Re: Extruder problems Replicator 2

[Robert Bonenfant]

Maker sure you clean the drive gear out with a tooth brush this same thing happen to me when i got mine. It could also be burn plastic but i would try cleaning the gear first then trouble shooting from there. Try unloading and loading your Pla a few time to try to push anything though that not suppose to be their. 

On Saturday, December 1, 2012 3:55:39 AM UTC-5, barbazoid wrote:

Hi everyone.

I really need help. Im new to all of this. I got my hands on a replicator 2 two weeks ago. I managed to print over the first week but just this week the extruder kept stopping halfway through a print. Now it's not even printing at all.

I've tried using this upgrade: http://www.thingiverse.com/thing:35810 but it hasn't solved my problem.

When I try to load filament the PLA just bunches up around the extruder (see pic) and only a very thin line of PLA is extruded at a strange angle until the filament seems to get stuck.

Is the actual extruder blocked, it doesn't seem to be my drive gear? Or am I missing something.

If it is the extruder - how can I fix it?

I would really appreciate any help because I'm pretty disappointed with the rep 2 at this point.

[Shawn]

I've seen that behavior with ABS. The culprit seems to have been a spec
of dust in the nozzle. After removing and cleaning out the nozzle
everything worked again.

Because you are using PLA, do NOT use acetone. Instead, the trick
mentioned by Robert might work - load/unload a few times, taking care to
snip off the end before reloading. This might clear the obstruction (if
that is really the cause of the problem). Failing that, the best
solution I've heard is to take the nozzle off, hold it with a pair of
pliers and run flame from a blow torch over it for a short bit. Care
not to a) burn yourself, and b) overheat/melt the nozzle. (I know I guy
who slagged his nozzle this way - we don't let him live it down. lol)
The goal is to get the flame into the nozzle and burn out anything
there. After it is cooled off, clear out the ash (water, compressed
air, etc.) and when ready remount the nozzle. The obstruction *should*
be cleared.

Hope that helped.

On 12-12-01 08:13 AM, Henry wrote:
> I have the same problem - but mine is only two days old. Not been able
> to print even one test print. Mr Jaws you are elusive ! Going to try
> cleaning the drive gear now.

>
> On Saturday, 1 December 2012 08:55:39 UTC, barbazoid wrote:
>
> Hi everyone.
>
> I really need help. Im new to all of this. I got my hands on a
> replicator 2 two weeks ago. I managed to print over the first week
> but just this week the extruder kept stopping halfway through a
> print. Now it's not even printing at all.
>
> I've tried using this upgrade:
> http://www.thingiverse.com/thing:35810
> <http://www.thingiverse.com/thing:35810> but it hasn't solved my
> problem.
>
> When I try to load filament the PLA just bunches up around the
> extruder (see pic) and only a very thin line of PLA is extruded at a
> strange angle until the filament seems to get stuck.
> Is the actual extruder blocked, it doesn't seem to be my drive gear?
> Or am I missing something.
>
> If it is the extruder - how can I fix it?
>
> I would really appreciate any help because I'm pretty disappointed
> with the rep 2 at this point.
>

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[Henry]

Reading the details of that answer I can see my problem is similar but different. Extrusion starts but then fails part way through the print. Plastic flows slowly and then not at all - leaving little balls on plastic on the print. Trying the load sequence shows it to be blocked - no plastic feeds through. If I unload and load again the filament runs again but still fails part way through the print. The plunger pull is strong so that isn't the problem. I am a noobie to this so little unsure what to do next. Going to try raising the temperature 10 degrees to see if that aids flow.

I've only had the machine two days and have successively only printed one thing (and that took 10 tries). :(

[Dan Newman]

On 1 Dec 2012 , at 7:13 AM, Henry wrote:

> I have the same problem - but mine is only two days old. Not been able to
> print even one test print. Mr Jaws you are elusive ! Going to try cleaning
> the drive gear now.

Have you tried tightening the plunger? See this video from MBI support,

http://www.youtube.com/watch?v=QOJN_8AAC9U

Although, I do have to wonder how easy it is to load in new filament after
things have been tightened that much.

Dan

[Dan Newman]

BTW, the above assumes that consistent feeding of filament is the problem.
If no filament will feed, then it could be that the section of filament
against the pinch gear is stripped in which case your cleaning plan is
a good step to take. Or it could be that the plunger is too tight.
Or, an actual jam in the extruder nozzle. (There's a support video from MBI on
clearing those as well.)

Dan

[Henry Shelford]

Thanks for the response. I did see that video and did the plunger test and it is pulling strongly. So I didn't tighten it. Plunger being too strong isn't something I had considered. I will look into that.

Right now I now have a new problem that the filament isn't feeding at all. It just clicks ! Have just opened it to clean it. But there really wasn't anything there. About to try to feed it now !....

...right that didn't work. Still clicking.

Dan

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[Henry Shelford]

Click is dealt with ! Bit of filament stuck in top of the extruder !

[Dan Newman]

On 1 Dec 2012 , at 9:54 AM, Henry Shelford wrote:

> Thanks for the response. I did see that video and did the plunger test and
> it is pulling strongly. So I didn't tighten it. Plunger being too strong
> isn't something I had considered. I will look into that.
> Right now I now have a new problem that the filament isn't feeding at all.
> It just clicks ! Have just opened it to clean it. But there really wasn't
> anything there. About to try to feed it now !....
> ...right that didn't work. Still clicking.

That's likely either

1. The filament is stripped at the gear -- you did remove the filament first,
before cleaning, right?

2. Or there's a jam of some sort and the stepper motor doesn't have enough
torque to turn the gear and it's slipping.

Jams can be: the plunger is too tight given the filament's current diameter
being presented or there's physical blockage in the extruder nozzle and you
simply cannot advance the filament through it. (I suppose that with the stepper
motor removed and the nozzle heated to temp, you can see if you can by hand
push filament through the melt chamber.)

Dan

[barbazoid]

Thanks everyone for your replies.

Looks like it must be the extruder as I've tried everything re: the drive the gear and filament.

Didn't want to be pulling apart the extruder this early in the game but will have to! I'll let you know how it goes.

[Big-E]

I've been having similar problems recently. I've tried to print a Yoda bust, got just past the eyes and it stopped extruding. This was using a minimalistic extruder which you can find at http://www.thingiverse.com/thing:36482

The V2 extruder at http://www.thingiverse.com/thing:35810 had issues too, I printed this twice, first in natural, and then in green PLA,  and tried a multitude of springs. the big spring version (the first link I posted) had the best results, but as I said, just when Yoda was at 60 percent or so, it stopped extruding. as for the v2 extruder, it had issues, I printed a stretchlet and a comb, and with both, the prints came apart; it wasn't extruding enough plastic for some reason.

I may retry the v2 extruder again, I was checking clearances, and comparing the parts I printed, and some of them are off. it looks as though I can use the back part from the first set I printed, and the arm from the 2nd set and have one that is dimensionally sound. I have a feeling it's a leveling issue that made the pieces a bit off.

BTW, if you decide to go with the big spring version, I suggest shimming between the arm and the back piece with one or two M3 flat washers to get the bearing to line up correctly. as I said, I had the best result with that one. I haven't given up on a minimalistic extruder mod yet, but It's back to the stock extruder block until I get it sorted.

in the meantime, I'm designing an STL of the plunger so if it wears, I'll have a few printed out, ready to go. The best prints I've gotten so far have been with the factory extruder block.

BTW, could it be the temperature? I'm extruding at 230 degrees, but the green seems a bit thicker than the natural at that temp. any suggestions?

[Rich Thompson]

I had faced similar issues. The only way I could complete a print was to watch for the printing to start to go bad. ONce the print went bad, I would unload and re-load the filament and continue the print. I might do that 5-6 times during a small print. Support has been slow and has suggested only  the standard items (i.e. plunger fix, clear the motor).

I spent the last 48 hours gradually stepping back the temperature and testing with each color of PLA that I own...7 in total. What I have found is that my Rep2 prints best around 195C for big prints and a bit less for small prints. There are small differences in PLA color as well, for example, clear blue seems to work best around 189C. I choose to keep the speeds consistant at 80 / 110.

So now, for the first time in about a month, I am starting to complete some prints without having to monitor the Rep2 and unload / re-load filament.

Of course, I sacrificed many penguins during testing:

[Big-E]

Thanks for the reply, Rich. I didn't figure on running temps that low, although I've found that small prints turn out great on the factory temperature settings @ around 230C (the stretchlet on the SD card prints even hotter @ 240C!) I was struggling today with a nozzle constantly clogging, I ran the load/unload process so much I lost count; I adjusted the plunger and went back to natural PLA, and finally got it extruding nicely again today. Even toyed with the High resolution settings a bit, but had to print at .15mm layer height (.1 still wouldn't work quite right)

I'll try to dial down the temperatures tomorrow. 189 degrees sounds like a good starting point; Thanks a bunch for the info; I'll give it a shot. if it works well, I may just go back to the minimalistic extruder and give it another try. Makes one wonder why MBI set the temps so high from the factory to begin with.

btw, While I had my extruder block out of the machine, I pulled out my calipers and designed a printable rep2 hollow-base plunger, I figured I'd print a couple just in case; they seem to print best at medium quality, .2 layer height @ 100% infill. doesn't seem to need support when printed nose-down, I haven't tried to fit it in the block yet, but it seems like it will work. If not, I'll revise it and post it to thingiverse when I've worked all the bugs out. It may be handy when the factory piece wears out and you're waiting for MakerBot to ship a replacement.

[Rich Thompson]

Don't forget that different PLA has different low temperature points. I found my transparent green needs to be closer to 200C to extrude properly. I am still experimenting with print size and temperature as well.

[Martin Galese]

I don't have a Rep2, but this sounds like a potential issue with retraction, particularly given the geometry that you believe causes the issue.  Each time the extrusion stops, retraction pulls the filament up to create a "sucking" force and keep plastic from oozing out.  It then reverses the process before starting to print again.  PLA, particularly at higher temperatures, doesn't seem to like this at all and jams.

Have you tried reducing the temperature?  I'm able to print very consistently at 205C with PLA on the Rep1.  Retraction set to 2 mm @ 80mm/s, usually.  You could also just try turning retraction off completely and seeing if that fixes your problem.

I don't think you can control retraction through MakerWare, but you can edit retraction settings in the Dimension plugin of Skeinforge. 

On Mon, Dec 10, 2012 at 12:15 PM, Joseph Adams <jad...@zdr.com> wrote:

Rich, what settings have you determined are best for natural PLA filament?  I've been struggling with the same exact issue since I received my Rep 2 a few weeks ago.  I've been attempting to communicate the problem with Makerbot support via e-mail but the particular representative I've been dealing with doesn't seem to be taking the time to read my detailed e-mails and has been less than helpful so far. 

I've been doing some methodical testing as well in an attempt to pinpoint the problem but haven't experimented with temperatures too much, only enough to convince myself that it seems to be a problem with settings/software and not the extruder plunger adjustment (took me a week to convince Makerbot of this).  My rep 2 prints the samples on the SD card perfectly and consistently without any extruder jams, but I haven't been able to print anything from code that I've generated myself without the extruder jamming. 

What I have determined on one particular model that I've been testing with is that it seems to run in to trouble when there is what I call interrupted geometry i.e. geometry that causes the extruder to stop and start multiple times on the same layer.  It happens consistently and repeatably when the machine starts building the same features of my test part.  It just may be a coincidence of timing though because I know of the same circumstances occurring on the samples provided on the SD card (chain_linked comes to mind) that print fine.  And I'm 100% certain that it's not a drive wheel/plunger problem because the stepper is skipping steps when the jam occurs, which indicates that the drive wheel has a very good grip on the filament.  I've also upgraded the plunger with the MK8 upgrade (http://www.thingiverse.com/thing:35810).  Since the stepper is skipping, I believe this also eliminates the possibility that the filament has become too soft at the grip point from excessive temps.

This is becoming a really bizarre problem to me because I have difficulty understanding how the filament can be flowing fine and then all of the sudden be jammed without an apparent physical obstruction.  At one point I theorized that the filament feed rate was too high because the problem is exacerbated with really small layer heights (.01) and my thinking was that the counterpressure was too high inside the nozzle.  But although jams occur less frequently at larger layer heights, they do still occur.

I will continue testing and sharing what I learn, any suggestions are highly welcome and appreciated!

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Martin Galese

[pfinucan]

From my experience, knowing only the temperature that someone was sucessful at doesn't help much.  That is because the volumetric rate of plastic they are melting is very important.  So you also need to know the flow rate, and layer height.  With the MK8 extruder your print can fail because you are printing too fast, or too slow.  Or another way to look at this is you are printing too hot or too cold. 

 

If you are running at a high feedrate, say 80 mm/s and a large layer height like 0.3mm, you are melting a lot of plastic quickly.  In this case if you temperature is too low your extruder will not be able to melt the plastic fast enough.  This will cause the motor to start skipping, (the click noise) or for the drive gear to strip the plastic filament.  If you see the motor click a couple of times but then continue, it is likely that you are running too cold.  The skipping gave the hotend a chance to catch up.  You can't see the gear strip the filament, the extruder will just slow and stop.

 

Now, say you got the printer to work great at 0.3 mm layer height and now go down to 0.10 mm at the same temperature.  The rate the plastic is flowing into the extruder is now reduced by a square root.  Now you are melting the plastic way to fast.  With PLA this cause the end of the filament to mushroom out, and melt further up the stainless steel tube.  Once it has mushroomed out, it will not fit into the nozzle anymore and will stall the extruder.  If you remove the filament you can see the mushroomed filament tip.

 

The tricky part is knowing which problem you have.  If you are running too cold, and the extruder jams, the filament will sit in the hotend.  If you wait too long the filament sitting in the hotend will have time to over melt and mushroom out.  So even though you print failed because your temperature is too low, it will look like it was too high, if you find it later.  So if you are having trouble, try to notice right when it fails.

 

On another note, retractions are also a problem area.  I would suggest turning it was down like 0.1mm or off if you are having jamming issues to rule that out.

 

Anyway, just my 2 cents, or may 5 cents.

 

 

 

 

 

 

[Joseph Adams]

Wow, you guys have been more helpful in the last 30 minutes than makerbot support in the last 2 weeks, thank you! 

Regarding the retraction, I was thinking that this could be the culprit myself and tried explaining this to makerbot but my comment went unaddressed in their last response.  I wanted desperately to try to turn this function off to see if it eliminated the problem but I didn't know how to do it through Makerware and I haven't been able to generate any usable code out of ReplicatorG yet (I'm a quite new to 3d printing and the Rep 2 is my first 3d Printer).  I've been learning alot about skienforge but I've been having some glitchy problems with the RepG software and it was making my learning curve that much steeper trying to distinguish between making the wrong selections and software glitches.  So I've been using Makerware primarily but forcing it to use the skeinforge engine with layer height at .15 and speed at 60mm/s and experimenting with different temperatures.  I've had the greatest success so far with this approach but obviously haven't solved the jamming issue yet.

As I write this I'm running a test print right now with the temp at 205, speed at 80 and layer height at .15.  I've already failed at these settings with a speed of 60mm/s.  I'm hoping the faster speed will prevent the filament from having enough time to mushroom at the nozzle tube entrance.  I'll let you know how it goes, but I feel pretty confident at this point (thanks to your help) that I'm on the right track!

[Big-E]

Hey Martin,

I think you're on to something here, I was testing most of the day yesterday, changing temperature settings and trying to get that yoda bust to print, I got a mostly successful print, but partially lost some layers midway through the job at 220C. I had to pause and screw around with the filament until it was extruding again, and resumed the print. The lower temperatures seemed even worse, and yielded less than 10 percent of a print.

I swapped the V2 minimalistic extruder back in, using parts from both my printed sets, and a much stiffer spring. I used the factory temperature setting of 230C and it printed perfectly. It seems the issues of clearances and spring pressure were finally resolved with this latest implementation, so, I believe you are correct in your assessment of a retracting issue. with a nice bearing idler under optimal tension, and no binding, it's no longer an issue, and my prints are coming out better than ever.

Next on my agenda is a decent set of feeler gauges and a dial indicator so I can get my bed leveled as best as humanly possible, at which point, i'm fairly confident I will be getting this machine to print as good as it can!

Thanks again for all the input. Maybe lower temps are more viable on other brands of filament, so far, I've only used MBI PLA, and it seems happy at the factory settings.

-Big-E

[Martin Galese]

Joseph,

You're right to think that faster may work better -- it is odd, but printing faster with PLA leaves less time for the filament to degrade within the extruder.  I'd try even faster.  Using Sailfish acceleration on the Rep1, I'm generally printing at 100-120 mm/s, at 205C and at .1 layer height without issue.  You might give that a try.

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Martin Galese

[Big-E]

Hey Jetguy,

Heat isn't a major issue for me, as I have a Replicator 2 (no heated bed). I have a Harbor freight near me, so Feeler Gauges and Dial Indicators can be had for cheap. Besides, I need the feeler gauges and dial indicator anyway to use in the garage, I need them to check valve clearance, spark gaps, warpage on brake rotors on my cars and other things. Still, I will give that thing you linked to a shot in the meantime; I won't be going to Harbor Freight for a couple weeks.

Also, using a dial indicator will let me know for sure if my build plate is warped, I checked it with a T-square out of the box, and it seemed pretty straight, but I won't know for sure until I use a dial indicator on it.

In all honesty, I'm sort of a cheapskate, if I can't find multiple excuses to buy something, I seldom invest my money in it.  :)

On Monday, December 10, 2012 2:48:10 PM UTC-6, Jetguy wrote:

No need for feeler gauges, just print this http://www.thingiverse.com/thing:21268

If the outer line is narrow or doesn't stick, you're low in that
corner. Too close, and the strip gets very wide. You can print this
multiple times and get it perfect. Further, because you are heating
the bed, then it's an accurate level, VS screwing around with feeler
and dial indicators. Sure, those ideas work on a real CNC machine made
of metal, but because MBI uses injection molded arms with built in
thermal stress, you must adjust it hot, in the same situation that
they would be used in. No better way to know than an actual print.

> > On Mon, Dec 10, 2012 at 12:15 PM, Joseph Adams <jad...@zdr.com<javascript:>

> >>> <https://lh4.googleusercontent.com/-dA6a1PdyjHs/UMPfKKYkwPI/AAAAAAAAAJ...>

>
> >>> On Saturday, December 8, 2012 10:54:43 AM UTC-6, Big-E wrote:
>

> >>>>  <http://i730.photobucket.com/albums/ww303/rave669/DSCF0578.jpg>
>
> >>>> <http://i730.photobucket.com/albums/ww303/rave669/DSCF0581.jpg>
>
> >>>> <http://i730.photobucket.com/albums/ww303/rave669/DSCF0580.jpg>
>
> >>>>  <http://i730.photobucket.com/albums/ww303/rave669/DSCF0584.jpg>

> >>>> I've been having similar problems recently. I've tried to print a Yoda
> >>>> bust, got just past the eyes and it stopped extruding. This was using a
> >>>> minimalistic extruder which you can find athttp://www.thingiverse.com/

> >>>> **thing:36482 <http://www.thingiverse.com/thing:36482>
>
> >>>> The V2 extruder athttp://www.thingiverse.com/**thing:35810<http://www.thingiverse.com/thing:35810>had issues too, I printed this twice, first in natural, and then in green

> >> To post to this group, send email to make...@googlegroups.com<javascript:>
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> >>http://groups.google.com/group/makerbot?hl=en.
>
> > --

> > Martin Galese- Hide quoted text -
>
> - Show quoted text -

[Joseph Chiu]

With my Replicator, I was having to re-level after each long print, or every few short prints.  Haven't had that problem since I started using the Replicator HBP height adjustment retaining jig -- http://www.thingiverse.com/thing:28723 -- 

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[Big-E]

That jig is pretty cool, maybe I should try to make one for my Replicator 2 (for the 3-point leveling system)
good Idea!

[Mark]

I had my R2 nozzle get plugged with something.  I used a fine wire, after preheating the nozzle and doing an unload, to clear out the nozzle.  Since then it is has been fine.  I've used up over 2 kg of filament over the last week printing parts with zero extruder issues (I have updated my extruder to use the spring-loaded filament roller too, and consider that an essential upgrade to the R2 extruder).

 

When my nozzle got plugged, the drive gear also got loaded up with plastic, so that had to be carefully cleaned.  But, zero problems since clearing out the plug.

 

I'm assuming some bit of foreign material got into my nozzle, perhaps because I was using PLA from a different vendor who perhaps doesn't have the quality control that the Makerbot PLA has (just a guess).  I mostly use PLA from Makerbot, but needed black for one of my projects and they don't seem to ever have that in stock.

 

The spring loaded roller was the 2nd upgrade I made to my extruder.  The first upgrade was to get the set screw of the drive wheel onto a flat on the motor, as my drive wheel was most definitely slipping on the stepper motor shaft.  Some people have extended the flat on the stepper motor shaft to accomplish this.  I flipped the drive wheel around, but this required milling a hole in the heat sink.  In either case, you'll need a slightly longer set screw for the drive wheel, so plan accordingly.  I think the stock set screw is a M3x0.5.  I could find one at my local hardware store, so I drilled and re-tapped the drive wheel to use a 6-32 set screw.

On Saturday, December 1, 2012 12:55:39 AM UTC-8, barbazoid wrote:

Hi everyone.

I really need help. Im new to all of this. I got my hands on a replicator 2 two weeks ago. I managed to print over the first week but just this week the extruder kept stopping halfway through a print. Now it's not even printing at all.

I've tried using this upgrade: http://www.thingiverse.com/thing:35810 but it hasn't solved my problem.

[Joseph Adams]

Well, after a night of testing I can report that I’ve had some successes as well as failures and frankly overall it was a very disappointing and frustrating evening!

 

In the success column, I was able to determine how to change the skeinforge parameters in Makerware so that I could turn off the retraction feature.  I also discovered the rest of the skeinforge plugins as well and now have nearly complete control over the code that skeinforge generates from Makerware.  Sadly, that’s where my success ends…  BTW, if anyone is interested, the settings are contained in CSV files in this directory: C:\Program Files (x86)\MakerBot\conveyor\src\main\skeinforge\Replicator slicing defaults\profiles\extrusion\ABS.  Be sure to adjust the settings in notepad, not excel which was my default program for opening these files.  The only thing I haven’t figured out is how to make the temp that you set in the Makerware print dialogue actually stick (seems to be a bug), so I have to add a temp line to the g-code manually to adjust the temperatures.

 

After turning off the retraction feature that I would have practically bet my life was the problem, I anxiously awaited a new test print (that I expected to be a success).  Well, I’m sure you can gather by now that it was anything but.  In fact, there seemed to be no effect at all; my results were exactly the same (except of course that the print quality wasn’t as good without the retraction setting).  So back to the drawing board as they say. 

 

I continued to try a variety of changes to rule out some variables such as time.  I generated code for only the top portion of my part, which contains the features that are giving the machine trouble.  This makes the testing go a little faster of course but it also forces the machine to get to the failing features quicker and thus eliminates heat soak as a variable.  Sure enough, the build failed at the same place it always has even though it took a fraction of the time to get there. 

 

Next I discovered that there are some settings in skeinforge that Makerbot specifically suggests changing if the build is failing in the way that mine is, namely the cooling plugin and the “restart extra distance” setting in the dimension plugin.  I confirmed that restart extra distance was 0 (as suggested by makerbot)  and I disabled the cooling plugin which was slowing the feed rate down for these features since they are relatively small.  Again, no effect.

 

The one thing that I have noticed to “help” is that the build seems to get further before failing if I leave the filament cooling fan off.  I haven’t tested quite enough yet to say that this is repeatable, but does seem to be trending this way.  I don’t know exactly what to make of this however or what impact this could be having that would cause the extruder to jam. 

 

I’ve just finished a couple test prints with the filament fan off and everything else constant but varying the temperatures.  So far I’ve tested (and failed) at 195, 205, and 215.  195 was definitely worse, 215 didn’t seem to yield any improvements over 205.  In all cases, feed rate is 80mm/s, and layer height is .15 and the natural PLA filament that came with the machine.

 

Since the build is fine and always fails at the same features, I think (someone correct me please if I’m wrong) that it’s safe to say that there isn’t any physical obstructions in the nozzle that need to be cleared.  I also measure the filament that gets extruded and it’s always about .41-.43 mm.  Knowing that the nozzle is .4, I think this is enough to say that there aren’t any obstructions.  Again, someone please correct me if I’ve missed something.

 

I’m now running short on things to try (not to mention patience) and getting utterly and completely frustrated!  Any ideas?

[Joseph Adams]

Ok, so here's an update.  I was having an utterly miserable day with the Rep2 this morning.  It seemed like things just kept getting worse instead of better (BTW, here's a little piece of advice, be careful to hold onto the filament when your snipping the end after it's jammed.  If your luck is bad enough, it will accidentally fall into the cooling fan and shear of a couple blades) anyway, I reached a breaking point.  I stopped everything, took a step back and took a breath.

I decided to tear down the entire hot end and see if I could learn anything.  After the tear down, there really wasn't anything obviously wrong, but at least I got the opportunity to learn how this thing was really put together and how it worked (surprisingly simple I have to say, maybe deceivingly so).  So in light of everyone's comments about suspected heat soak, I decided to add some thermal grease to the nozzle tube that threads into aluminum mounting block.  I was hoping this would reduce the thermal contact resistance between the tube and the mounting block and help dissipate the heat better in this area.  I also added some to the heat sink where it mounts to the block.  To finish it off I removed the plastic spacers between the cooling fan and heat sink and replaced them with some stout springs.  This would reduce any vibration from the (now damaged and out of balance) fan and prevent it from migrating through the assembly and affecting the build quality.  Even more importantly, it also provides a consistent amount of pressure between the heat sink and the mounting block regardless of thermal expansion of the components.

After putting everything back together, I re-leveled the build platform (which of course was important because I undoubtedly altered the height of the nozzle), reloaded the filament, started a new print and awaited another disappointing failure.

To my shock and (guarded) happiness, it completed the first print without jamming.  Maybe I'm on to something.  The settings for this print were temp at 205, feed at 80, no filament cooling fan, no retraction and layer height at .2 (notice I increased the layer height from my previous testing of .15)  From this point forward I continued testing and improving the settings one by one for each print.  Each time completing a successful print without jam.  Also, upon dimensional inspection i found that the machine was building more accurately than it ever has (+/- .002")

As I write this I'm finishing up a complete build (as opposed to the partial I was testing with) and all of the settings back to optimal including retraction and filament cooling, and it's looking good.  WHAT...A...RELIEF!

So, for the time being, it seems like my heat transfer improvements may have solved my problems.  I sincerely hope this can help others and prevent someone from experiencing the same frustration I have endured the last couple days.  On the positive side, I had the opportunity to learn the machine and software inside and out, so I'm much better off for it. 

I want to extend my most sincere gratitude to everyone here that took the time to contribute and help!  If anyone has any questions about what I did or how I did it please don't hesitate to contact me directly.  I would love to share what I've learned.

Thanks again to all!
-Joe

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[Jonas Andersson]

Wow, you have no idea how good it feels to see some progress on this problem.  I will absolutely try this tomorrow. Funny thing is I spoke to the local support about cooling paste for the heat sink to the alu block but they told me there was no need for that... :)

I will dig into thermal and cooling mods to see if it improves my feeding problems as well.

Joseph, thanks for sharing your improvements!

/Jonas

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[Joseph Adams]

Jonas, it’s my pleasure to share, I hope you find success as well.  One thing about your comment regarding your discussion with local support.  Although I’m sure that adding the grease to the heat sink helped, my gut tells me that adding the grease to the threads on the nozzle tube had the greatest impact.  So whatever you do, please make sure to at least add the grease there and make sure it covers the entire threaded length.  And of course be careful not to allow any to actually get inside the tube.  I honestly don’t know what it would do, but it’s probably not something you want to find out.  Good luck!

 

-Joe

 

[Joseph Adams]

Matt, I'm sorry to hear that you've been having as hard of a time as I have with makerbot support. I've taken a lot of time to compose extremely detailed emails to the tech support I've been corresponding with for two weeks and the responses I get are down right angering. It seems apparent that he isn't taking the time to read more than a few lines of my message and it takes him two days to respond with a less than helpful answer. Anyway, I can sympathize with what you are experiencing.

Regarding your problem, can you provide anymore details describing the settings that you have used so far? Feed rate, temperature, layer height, what software you're using and slicing engine (miracle grue or skeinforge)?

I just wrapped up the first successful day of printing that I've had since getting the rep2 a few weeks ago and I think that I *might* have finally gotten all of the kinks worked out so hopefully I can help you too! I am still a novice at this myself though so don't get your hopes up, but at least it seems like there are some very knowledgable and experienced users here to help if I can't.

-Joe

[Rich Thompson]

Joe, I will try this as well to see if I can get my inconsistent Rep2 to work. Lowering the temperatures has masked the real issue I think.

Also, please reference this thread on thermal compounds before trying this at home: https://groups.google.com/d/topic/makerbot/G66XxVhDi6Y/discussion

Rich

[Joseph Adams]

I’m not using exactly this size bearing but close.  I found one laying around my stash that was close enough (OD = 9.5mm and width is about 3mm) and it seems to be working fine.

 

-Joe

[Mark]

I tried all sorts of things to get my R2 printing well, temperature settings, speed, etc., etc.  The failures were random, so it would sometimes seem like something made a difference, but then it would fail again.

 

Fixing the drive wheel to the flat of the stepper motor and adding the spring loaded clamp was a 100% solution for me.  I've printed tons of parts now (~2 kg) with zero printing issues.   I just use the default settings for medium resolution prints.  High res still isn't working as well as I'd like, but I'm sure that's just settings that need to be tweaked.  The extruder hasn't skipped a beat since I made those changes.

 

Mark

[Jonas Andersson]

What I did this morning was to remove the heat sink and just bolted the fan on the extruder directly so the filament gets some air flow and knock on wood it has printed flawlessly (not a single load/unload since then).

No heat sink pasta added so far - instead I removed the heat sink... 

I should probably make a hole in the heat sink to get some airflow to cool the actual filament line... 

I got a load of colors from plastic2print this afternoon and the two colors I tried so far melt at a lower temperature than the originally MBI supplied transparent PLA. However these two also print just great at the default 230 degree setting...

... Knock on wood... !!! :)

/jonas

On Tue, Dec 11, 2012 at 11:38 PM, Joseph Adams <JAd...@zdr.com> wrote:

Jonas, it’s my pleasure to share, I hope you find success as well.  One thing about your comment regarding your discussion with local support.  Although I’m sure that adding the grease to the heat sink helped, my gut tells me that adding the grease to the threads on the nozzle tube had the greatest impact.  So whatever you do, please make sure to at least add the grease there and make sure it covers the entire threaded length.  And of course be careful not to allow any to actually get inside the tube.  I honestly don’t know what it would do, but it’s probably not something you want to find out.  Good luck!

 

-Joe

 

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[David Mytchak]

I have had my Rep2 for several weeks and had zero failure until this morning.   I was 25 hours into a print, checked it at 3 am this morning and BAM - JAM.   No clicking from the stepper - just dead space.  I just read this thread yesterday thinking "poor guys.  I haven't had any of these issues".  So at 3 am - I just turned the machine off and went back to bed.   So this morning I decided to fiddle with it before going to work and ran the filament load script.  I stepped out of the room for 10 seconds and when I returned, there was a big blob of goo on the build plate with another blob hanging from what looked like a deformed noodle.  The noodle did not look right - it was thin at points for several inches and then became a 'normal' noodle.   I let it run for a minute or so and the noodle looked good after the run.    Without having any of these issues before and the stepper was not clicking, I'm wondering if it maybe a bad batch of PLA or perhaps an issue in a section of PLA which caused the clog.    I'm off to a business trip today but wanted to share my experiences with the group.   

So here are my short facts:

- 25 hours into a print - clog

- No clogs prior 

- Extruder stepper was not clicking
- Machine cooled and then ran filament load - blobs of goo and deformed noodle

- After a short load run, noodle looked normal again

I'm going to take the nozzle apart and clean it this weekend.  More to come...

-David

[Joseph Adams]

I noticed something strange today that maybe you guys can help with.  My extruder is still functioning good now since my changes, but I’ve noticed some inconsistencies in the build depending on how the code is communicated to the machine.  Here’s the story…

 

So there are some minor things I’m trying to tweak now that I’m finally building good parts.  Things such as the fact that Makerware is ignoring the temps I tell it to build at, forcing me to manually modify the code to add a M104 line.  Not a big deal but a nuisance to be sure.  So I decided to use ReplicatorG to send the code to the machine.  I’m using the same code that I generated from Makerware and have several successful and consistent builds from.  The only thing that I have done was add the start and end code to home the axis and start heating the tool prior to the homing sequence (another annoying thing Makerware doesn’t do).  After I add those sections I start building, and everything mostly builds well except when the machine begins to build the features that I was having trouble with before.  Now it doesn’t Jam outright, but it definitely is not feeding filament properly and I can hear the stepper skipping every once in a while (even on layers that didn’t have a problem before).  I’ve reproduced these results three times now.  So I thought maybe it was a data transfer/communication issue so I exported the code (through RepG) to s3g to the SD card and built from the SD card…same result.  I went back and printed (using the same code again) through Makerware sent directly to the machine (not SD card) and perfect build again.   What I haven’t tried yet was exporting through Makerware to the SD card and building from that ( I will try this next).  But this is weird isn’t it?

 

So here’s the summary:

Parts built from code communicated to the Machine through Makereware; perfect build

Parts built from code communicated to the Machine through RepG; no good

In both cases the code is exactly the same except the for the start and end code (although I don’t know if is or isn’t the same because I have no way of verifying what Makerware adds to the code when it is sent to the machine)

 

Any ideas?

 

-Joe

[riggeek]

Printed this calibration test http://www.thingiverse.com/thing:34692 with PLA on my stock Replicator 2, using Makerware medium 0.27mm layer height, 230c temp, and 10% fill. Seems OK to my eye. There were a few problems with the extrusion pattern starting crosswise on some of the early bridges, causing stray filament, and the first bridge layer is stringy (detached from the ones above it) but the rest of the bridge layers are solid. I am going to play around with different temp settings and see what effect they have. However currently I am printing a 0.1mm version for comparison so I will post when its done.

[Big-E]

I have a similar issue now, I can print at medium quality, as soon as I try a high quality print, the machine just refuses to cooperate, as if it's not extruding enough plastic. I tried to print a creeper model for my son, I got a raft, and shortly after that, the extruder did nothing, the nozzle was a few inches off the build plate, nothing coming out. I had some success before with a .15 layer height setting, and now, that doesn't seem to work either.

Miracle Grue sliced prints (at low or medium quality) print perfectly now. I noticed almost no plastic blob at the start of a print though, but on High quality prints, there is always a clear, defined line at the start of the print, even if it eventually fails.

Tomorrow, I'll try pulling apart the hot end a bit, starting with the nozzle, to check for clogs and debris. I may also try ReplicatorG to see if I can get some improved prints in higher resolution; was planning on trying that out anyway.

If I can get High quality prints to work as well as my medium quality prints, I'll be a happy camper.

I'll post some updated info if I discover anything.

[WMc]

Great discussion going on here and like many others my brand new Rep 2 also stops midprint.  Makes great 3d air models, perfect every time!   

 

My prints are almost perfect for few sets of layers, it then goes fluffy and noisy at the surface and then dead.  The only thing that changes is the time which it goes through these 3 phases.  The only thing I can thing that makes sense to me is the feed is jamming but not due to anything mechanical.  I can instantly unload,reload and extrude no problems.  Mushroom effect most likely maybe?   

 

Anyway I am thinking more and more about the heat transfer up the filament and the mushrooming effect which jams the extruder.  I was thinking of putting the filament spool and guide tube into the freezer in an attempt to increase the differential temp between the tip and feedin filament. 

 

I only have one roll of natural filament with my new machine and can't get anymore here in asia at the moment so don't want to trial this right yet.  To the more knowledgeable out there, is there any merit to this idea or has anyone tried anything like this?

 

Would love to do the MK8 upgrade but can't print the parts. 

 

 

[Big-E]

I've gotten my Rep2 to print well at low and medium quality. The Mk8 minimalistic extruder is the reason this works. I've considered adding a flat to the stepper motor's shaft so the extruder gear won't slip, as the set screw really needs to torqued down on a flat spot to properly lock the gear in place. Why MBI didn't do this at the factory is beyond me. It may be fine with ABS, but PLA seems like a harder filament, and when it tries to retract the filament, the little indentations made by the gear seem to get stripped (hence, you hear lots of clicking and the filament gets stuck) like stripping the gears in a transmission.

Natural PLA works pretty good for me, it seems to come out easier and has a runnier consistency when melted. Now that I think about it, the only success I've had with high-resolution prints have been with natural PLA, with supports and rafts turned off. I'd definitely say the temps need to be lower, since it seems to come out runny (the prints end up oozing a bit, an taper wider near the build plate more readily too)

Try tightening your plunger, I was able to print the parts just fine. Turn the little set screw in the block to snug the piston up to the filament, but don't over tighten it. you may also want to tighten the set screw on the extruder gear. remove the stepper motor (with the extruder block attached) and make sure that screw is snug. There are some good support videos here that will help: Makerbot support videos. Thanks to Dnewman for posting the link to these.

When you print them, print each part, one at a time, with 2 shells @ 100% infill no raft, no support, and make sure the bed is as level as you can get it. acceleration should be turned on on your bot.

Some notes on installing the extruder mod: You still may need to file the outer-facing side of the idler arm (the part with the bearing) to allow for the proper clearance, and only the outer face, so the filament guide hole lines up with the gear. Make sure the assembly, when held together in the working configuration, is not thicker than the factory extruder block. You may need to try a few diffeernt springs to get it to work properly. I tried several, and found one that works. I'm still swapping in different springs in an effort to get it just right. make sure not to over tighten the top-left screw, tighten it enough to keep the parts snug, but not so tight that they bind up and the arm moves freely without any slop. You may want to sand the inner surfaces where the two parts make contact, so there is less friction between the two faces, but don't overdo it, you don't want to take off so much material that the bearing or filament guide don't line up properly. if you do accidentally take too much off, use an M3 washer or two to shim the arm so everything lines up correctly. If you can't find an M3 set screw to mount the bearing, like me, use a similarly sized M3 machine screw, and install it with the head facing towards the stepper motor to avoid clearance issues, it works just fine.

Hope this helps, and good luck.

-Big E

[Steve]

-Big E:

Are your replacement extruder instillation steps for the one that requires cutting a part on the Rep 2, and if so just

what cut is required? There is also an extruder replacement that does not require any cutting on the Rep 2. I am trying to

understand which one you used and how to best install it.

[whpthomas]

I printed the same calibration test http://www.thingiverse.com/thing:34692 with PLA on my stock Replicator 2, this time using Makerware with the high setting 0.1mm layer height, 230c temp, and 20% fill. Compared to medium, the sagging on the bridges is about the same, but the fist layers on each bridge appears to be more are more stringy, even though the strings are finer. There is obviously an overheating problem with the top three layers causing smeer on the sides. Clearly printing small parts in HQ is going to be an issue until we can tweek these settings - i.e. the cooling delay needs to be greater for small layers - or for smaller parts maybe consider running at a lower temp in HQ. The earlier medium print had no problems with this.

[Big-E]

On Thursday, December 13, 2012 11:14:01 AM UTC-6, Steve wrote:

-Big E:

Are your replacement extruder instillation steps for the one that requires cutting a part on the Rep 2, and if so just

what cut is required? There is also an extruder replacement that does not require any cutting on the Rep 2. I am trying to

understand which one you used and how to best install it.

Hi Steve,

I used the no-cutting version, there are also three different versions of the no-cutting version:

The original V1, and the V2, which are both at this link: http://www.thingiverse.com/thing:35810
and the version for larger springs, which is at this link: http://www.thingiverse.com/thing:36482

I have made the V2 and the large spring version. the large spring version is like the V1, only it is designed to accept a fatter spring. both the V1 and large spring versions require extra work, one of the holes is a bit off, and needs to be widened to get the screws to line up to the motor properly, I also needed to use two M3 washers to get the filament guide and bearing to line up. The V2 addresses these issues, but may still require some fine tuning to get it to work, but all the parts line up correctly. I am currently using the V2 mod, and my earlier post was addressing that version. However, my earlier explanation will help address issues with any of the no-cutting versions.

For the record, I have tried both the V2, and the large spring version. I have had the best results with the V2. I have printed it twice, and have parts from both of my printed V2 sets in my setup (which were selected for print quality and dimensions to allow for the proper clearance) This is why I suggest printing each part individually, rather than both on the same build plate.

Hope this clarifies things a bit.

Oh, btw, there's another extruder mod that shouldn't require cutting, and it appears perfect for the Rep 2, I've considered trying this one too. you can find it here if you want to try it: http://www.thingiverse.com/thing:24644

[pfinucan]

So I just spent a month fighting a MK8 clone on a printer I made.  Here is what learned about this extruder:

1. Temperature is a function of feedrate and layer height.  If you are printing at 80 mm/s at around ~.25 mm layer height you can print PLA at 230C, if the feedrate or the layer heigh goes down, the temperature should too.

2. Do NOT under estimate the problems back-pressure can cause.  I found that if you have problems in the middle of a print then look to back pressure

3. Back pressure can be caused by build plate level, Z level start, or over extrusion

4. I solved jamming issues by changing the filament dia from 1.73 to 1.75, which decreased the amount of filament being extruded.

What surprised me the most is that modest over extrusion causes chronic jamming.  If you have problems with jamming try setting the filament too thick as a test.  If you jamming issues start on solid layers, that is another warning sign. 

Anyway, something else to try.

On Thursday, December 13, 2012 10:04:23 PM UTC-6, Ichigo wrote:

Hey, I just wanted to give you guys an update... After a week and a half of brutal, brutal, painful troubleshooting, we were able to get our Bot back up and running better than ever thanks to the mk8 upgrade.

http://www.thingiverse.com/thing:35810

I had a bitch of a time trying to find bearings, a hobby shop is your best bet honestly(specifically helicopter). I went to about 15 different places in Los Angeles in terms of hobby shops and hardware stores... Anyway, the 3x8x4 bearing was definitely too small but the 5x10x4 did work.

We also removed the heat sink.

Just out of curiosity I tried lowering the temperature to 189, as we use clear blue(though we have a plethora of other colors) and I had been reading that a lot of people are having problems with their Rep 2 would see success(using clear blue) if they lowered the temperature to 189. I did not see any sort of improvement, in fact... with the modification, the clear blue would not extrude at 189.

I hope this is helpful...

[whpthomas]

Coming to the end of a marathon 10 hour 3D print run making a StarWars X1 Tie Fighter for my son. This was done with MakerWare high (using skeinforge) with 0.2mm layer height - so it didn't take forever! No jams at all - my Replicator 2 is running flawlessly. So adjusting the filament pinch grub screw seems to have sorted out the extrusion problems for me - at least for today ;)

[John Biehler]

I've been having a number of issues with my Rep 2 extruder...even after unclogging the nozzle and stainless tube (thanks to some burnt up PLA blobs from some cheap filament from China). 

Removing the heatsink seemed to be the trick to get better airflow to the filament drive and prevent it from getting too soft and buckling. It's also much easier to monitor things and guide the filament to it's destination when loading. Thanks for that tip, Ichigo!

Strangely though, my fan is now on 100% of the time...even after finishing an overnight print, it was still on this morning despite the print finishing hours earlier. It's also louder now thanks to my knocking 2 different fins out with the m3 hex key while trying different things.

[tomlombardi]

I've had a Makerbot TOM since the MK5 days, I've done all the upgrades even replaced the stepper drivers with Pololu. I've always felt like a beta tester, then my wife secretly orders me a Replicator 2 for Xmas! I found out only because she said my gift would be late. I thanked her then I CANCELLED THE ORDER!
Don't get me wrong, I have a strange admiration for the people at Makerbot, however you'd never catch me spending $2300 to be a beta tester again.

BTW, Makerbot TOM + MK6 + Sailfish + Slic3r = unbelievably beautiful prints!


On Tuesday, December 11, 2012 9:15:02 AM UTC-7, Jetguy wrote:

Sorry and I know I'm harping but does any one else find the number and
complexity of fixes we must apply on the latest machine to be
excessive? More or less, modify many aspects of the extruder including
the filament drive, deal with some of the same bed issues from the
previous Replicator 1.

I say that because this thread is a text book example of who Makerbot
targets this machine for:
http://groups.google.com/group/makerbot/browse_thread/thread/bd3610b4df391999
This quote says it all:
"I'd rather not have to completely hack the machine. Please keep
replies as
non-jargony as possible. "

This guy certainly isn't going to file the shaft or mill out the
heatsink to fit. Heck, he can't even get his X-Y working to see later
on he has an extruder problem that hasn't come up yet.

Sorry for the rant but am I the only one who sees this? And what's the
fix in this guy's situation? Either, he has an uphill learning crash
course in mechanics, or that machine is going back to MakerBot for
repairs. Hopefully, he hooks up with somebody local, but basically as
I said, that is text book MBI's target market for the machine right
now. None of the fixes seem appropriate given his initial response and
lack of desire to jump into the mechanics of the machine. How is this
guy going to handle a nozzle clog? Would he even attempt to replace
the filament drive with a printed one? How many failed prints before
he gives up? I'm not trying to be off topic, just understand how the
problems and solutions in this thread apply to the new MakerBot
Operator generation who has zero interest in the mechanics of the
machine and expects it to work like the office copier? I know  I made
a massive generalization there, but we see it every single day in the
questions asked here in the forum.

So I guess the real question is: Does MakerBot have any formal
representation reading this forum and are any of these lessons learned
being taken to the engineering and customer support teams for
resolution? In other words, changing directions, changing parts and
making the new kits better and offering upgrades for early adopters?
Or is everybody totally F'd in the A again and told to buy a new bot
next December, or maybe they do a Mid Year upgrade? MakerBot support
is nice enough, but seriously missing the mark as a "Grown Up Company"
that Bre kept reciting at the release of the new machine. Real
companies don't release a 4th generation product (Unless you're Apple-
facepalm) that has problems they knew about in previous generations.

I want this to be more than a gripe, but rather a serious question
about what is MBI doing to fix the problem? What can we do as a
powerful group to better help the poster I linked?

Also, I'm going out on a far limb here, but let's take the number of
problem posts per day since release, figure in a factor  of how many
people who have a problem even know to join and ask in this forum, and
compare that to toal number of units shipped. A lot of those are
factors only MBI knows, but it's not too hard to see the numbers could
be interesting. Either a ton of these work out the box with 0 problems
ever, or there are a lot of users in frustration, who may not even
know to go here and either deal with MBI support directly who may or
may not resolve the problem. What about repeat problems?

Again, is what we are seeing in this thead a common design issue, or
minor tollerance issues and one-offs? How would a person who doesn't
want to take the bot apart deal with that issue? Is it a user training
issue? Is it a default software setting issue(temperatures for
example). I'm just trying to identify the bigger picture fix.

On Dec 11, 10:23 am, Mark <m...@kenworthymachine.com> wrote:
> I had my R2 nozzle get plugged with something.  I used a fine wire, after
> preheating the nozzle and doing an unload, to clear out the nozzle.  Since
> then it is has been fine.  I've used up over 2 kg of filament over the last
> week printing parts with zero extruder issues (I have updated my extruder
> to use the spring-loaded filament roller too, and consider that an
> essential upgrade to the R2 extruder).
>
> When my nozzle got plugged, the drive gear also got loaded up with plastic,
> so that had to be carefully cleaned.  But, zero problems since clearing out
> the plug.
>
> I'm assuming some bit of foreign material got into my nozzle, perhaps
> because I was using PLA from a different vendor who perhaps doesn't have
> the quality control that the Makerbot PLA has (just a guess).  I mostly use
> PLA from Makerbot, but needed black for one of my projects and they don't
> seem to ever have that in stock.
>
> The spring loaded roller was the 2nd upgrade I made to my extruder.  The
> first upgrade was to get the set screw of the drive wheel onto a flat on
> the motor, as my drive wheel was most definitely slipping on the stepper
> motor shaft.  Some people have extended the flat on the stepper motor shaft
> to accomplish this.  I flipped the drive wheel around, but this required
> milling a hole in the heat sink.  In either case, you'll need a
> slightly longer set screw for the drive wheel, so plan accordingly.  I
> think the stock set screw is a M3x0.5.  I could find one at my local
> hardware store, so I drilled and re-tapped the drive wheel to use a 6-32
> set screw.
>
>
>
> On Saturday, December 1, 2012 12:55:39 AM UTC-8, barbazoid wrote:
> > Hi everyone.
>
> > I really need help. Im new to all of this. I got my hands on a replicator
> > 2 two weeks ago. I managed to print over the first week but just this week
> > the extruder kept stopping halfway through a print. Now it's not even
> > printing at all.
>
> > I've tried using this upgrade:http://www.thingiverse.com/thing:35810but
> > it hasn't solved my problem.
>
> > When I try to load filament the PLA just bunches up around the extruder
> > (see pic) and only a very thin line of PLA is extruded at a strange angle
> > until the filament seems to get stuck.
> > Is the actual extruder blocked, it doesn't seem to be my drive gear? Or am
> > I missing something.
>
> > If it is the extruder - how can I fix it?
>
> > I would really appreciate any help because I'm pretty disappointed with
> > the rep 2 at this point.- Hide quoted text -
>
> - Show quoted text -

[WMc]

Hi,
I am also having extruded jams on my new rep 2 which causes prints to fail anywhere from 0 to 50% of the build. I want to attach a photo of the filaments after they are unloaded after a jam because I believe it shows the symptom for the problem occurring. How can I attach a photo in this forum? In short it repeatedly shows a filament end which starts skinny as expected for the nozzle ID, then fat at approximately 1.75mm dia but slightly mangled but obviously un melted then above that melted again down to a skinny diameter. This is all within the filament barrel/nozzel. This upper melted section above the unmelted section strikes me as a real problem. Surely this points towards a problem in the hot end. It is no wonder the extruder is jamming. Any ideas of the cause?

Thanks,

[WMc]

Hi,
Further to my post before this, here is a link to a photo of the removed filaments. Can anyone tell me why there is an unmelted section between 2 semi melted sections? Thanks,

http://www.flickr.com/photos/91502513@N03/8307830165/

[whpthomas]

Mine look the same as yours - but no problems with my extruder (Unmodded Mk8 o Replicator 2) so maybe this is a red herring.

[Patrick Finucane]

I have seen that.  It is caused by backing up the filament or pulling it out of the extruder by hand.

From my experience it isn't the cause of extruder problems, more like it happens after the extrusion stop and the filament is removed.

It is possible that if you are running too hot or too slow that too much of the filament is melting.  So not just in the nozzle but up into the ss tube also.  Then when you pull it out the melted plastic stretches.

--

[WMc]

Cheers for the replies, I'll start looking else where for the cause of the jamming. I've tried temperatures all the way from 190 to 245deg c. I watch the drive gear at the point of failure and I can see that the drive gear stalls, not slip (as mentioned in some other posts). The filament is obviously jammed solid somewhere in the barrel or nozzle. It comes out no problems and reloads no problems. As soon as I then try to pint all problems start. At 190deg it fails almost immediately, at 245deg it is much better but still fails eventually. I don't want to go any higher in temp but I can't help but feel the problem is getting better as I go higher and higher in temp. Is it possible the temp read out is really off and I am only just reaching the real temp of pla melt? I have just bought a laser temp thermometer, will test some components later and report back.
I know this is probably a really annoying topic as it is so common. It might be worth building a troubleshooting flow diagram to solve these extruded problems. I am thinking of including infared non contact temp readings of different parts to better diagnose the problems here. I am happy to do this but unfortunately I don't know enough about the solutions yet.
Cheers,

[whpthomas]

I just had an extruder failure for the first time, and it was because I setting the Cool: minimum layer time in ReplicatorG to 10 seconds - 2 seconds seems to work better for me. What I noticed is that as the printer slowed down on smaller layers, all the filament in the heating chamber oozed out, and there was nothing left in there to print with. So here are some random thoughts. Is you printer printing as high speed - 80 mm/s feed rate & 150 mm/s travel rate, acceleration turned on in the Rep2 settings menu? If you are using ReplicatorG theck the settings in Cool for minimum layer time. Also if you have adjusted your delrin plunger, make sure that it is not too tight - this will also cause filament feed problems if the filament diameter is inconsistent.

[BilbyCNC]

Check the plunger is tight (pg 52 in the manual). Also make sure it does not have wear line that is effecting the pressure it is providing against the filament.

When the plunger is too loose you will see a thin stream and/or intermittent flow to no flow depending on how loose it has become. Once it is a little loose it can vibrate looser during printing

Good luck
Lee
BilbyCNC

[WMc]

Hi Guys,

All good ideas and now I am back printing more or less successfully.  Added thermal paste to nozzle and heat sinks.  Mk8 upgrade complete and installed (had to unload and reload the filament 10 times just to print the 2 parts!).  Glass build plate cut and installed and blue painters tape added.  Default rep 2 settings in Repicator G and I can now print the example objects without failure, what a relief!  Desperate times called for desperate measures but one of them has paid off.

So onwards to the specific part which I bought the printer for.  My first attempt is an innersole for a shoe to test how a printer could cope with organic surfaces.  No real reason for the choice of part other than it fills the entire build platform and demonstrates organic cures from a 3d printer.  First attempt last night went ok until it jammed and stopped.  The jam occurred during a period of infill where the extruder is going crazy in a back forth motion.  The innersole part I modelled is only 1mm thick throughout the contoured surface.  I turned on supports.  What happens is on each layer there is a few shells laid down around the contour then filled in with a violent oscillation to paint the infill.  It is during this infill that the extruder jammed.  I caught one of them in the act so was able to unload and reload without losing the print.  The second time it jammed it required a disassembly of the extruder to remove an obstruction at the filament tube.  So that was the print cancelled and unfinished.  

Is there any way to restart a build midprint but not just using the pause un-pause function?  I needed to turn the bot off to clear a jam, but then there was no way to pick up where it left off, the unpause option is lost once the bot is rebooted. 

Here are the photos of what did print:

http://www.flickr.com/photos/91502513@N03/8313683868/

http://www.flickr.com/photos/91502513@N03/8313679384/in/photostream/

Cheers,

   

  

  

  

[Chris Milnes]

Those look perfectly fine actually.

[whpthomas]

I have found that flat organic shapes are the hardest to print.

[barbazoid]

Hi everyone,

So it's been a few weeks and I have had no luck. I've pulled my replicator 2 apart, tried everything mentioned on this thread and still have had no luck.

My replicator 2 will load filament fine, no problems. But as soon as I start to print it starts clicking away and nothing comes out.

Really, I'm pretty disappointed. Don't really think that makerbot could call this prosumer with the issues i've been having.

If anyone has suggestions I'd really be interested!

[Henry]

Long pause here too - Christmas etc - and then got back at it. Sad to say I have also given up.

I've kept a record of my attempts. I am now at 70 print starts. Tried various temperatures, resolutions, stock files, plunger tightness, multiple unnecessary cleaning of the filament feed - all without getting it to properly work. I can't print reliably, rarely anything over 3mm high, NEVER anything bigger than a few cm cubed, and NEVER anything above medium quality. I just get airprints. Lots and lots of airprints.

Support are next to useless. They take a long time to respond and then with useless exercises "can you print this" rather than any kind of solutions. Complicatingly I have been able to print one of their files - anyone want a stretchy bracelet !? - but I can't print any of the other objects. The elusive Mr Jaws. Or something I actually want to make. It makes me feel it could work. But something is clearly not not right.

I've seen the links to alterations but I am not willing to mod the machine at this stage. Partly because I shouldn't have to. No machine should require altering to perform its basic functions. Partly because if I do I'd invalidate any warranty / consumer rights.

My machine is a complete dud. It absolutely doesn't do what it says it does. Looking at the comments here and the 1000+ views of this thread I am not alone in this.

I think we're at the stage they need to show it can work rather than continue to put time in trying to prove it can work. 

So I've asked them to take it back. If they can make it reliably work they can send it back to me. Otherwise, I've asked for my money back. In the meantime I am eyeing up the formlabs one. I am genuinely sad that my makerbot doesn't work.

[bart.s...@ichoosr.com]

Henry,

Same here. 

I have 2 R1 in basement and they print super, but after 2 weeks trying to tweak the R2, I give up. Am not able to get some consistent out of it.

Please keep the group in the loop about your discussion with MBI.

Bart

[John Watson]

HI ALL
well after a week of tweakeing and pulling and pushing and leveling and reloading and cleaning
I seem to be getting prints ...I am going to keep going today  to try and keep the ball rolling
heres a list of the things I have found

1) Pinting heat at 220 seems to be the happpiest range for me..
2) this is a big one ...the fan and heatsink were actually on the wrong way round  or if they werent I turned them round  so the fan is blowing onto the heatsink fins not drawing it away
3) I did the adjustment  with the side fan of and kept tweaking the plunger till I could not stop it with 2 fingers squezzed together as hard a s I could ..then gave it a 1/8th turn to make sure
4) checked all my stl files with netfab to amke sure they were good
5) only printed using the sd card ..after exporting with repg software and making sure  use default start and end gcode was checked  and use printomatic was checked and replicator2 slicing profiles were used .
6)used blue tape ..but made sure I cleaned it with alcohol or a touch of acetone

I have now done 3 prints so far which I will upload when I get a chance ..but I am back at it  again so will keep you informed
happy new year
John

[whpthomas]

Henry: very sad to hear that you have had such bad luck with your Rep2. No fun at all. 

In my limited experience, I have only had white PLA fail to print like this. It seems very temperamental, however it was worse when my build platform was floppy - the rubber pads it sits on had squashed down and I could grab it on the side and shake it up and down - it was not snug against the clips that hold it in place. I just used a few layers of paper - underneath the build plate to raise it up until it was snug. After that, combined with using my interactive build plate levelling aid http://www.thingiverse.com/thing:39430, tightening the extruder grub screw, and changing the ReplicatorG Diameter packing density to 0.97 - I had a lot more success with white PLA.  What I suspect happened was that when the build platform wobbled side to side, it changed the back pressure in the nozzle - maybe more filament oozed out, not really sure, but something would go wrong in the extruder and it would start air printing, like you say. When I did a load/unload globs of snotty plastic would spit out in a splutter and then gradually a strand of filament would come out, first inconsistently and then finally in a continuous solid stream. No Idea why this happened - or really what caused it because I changed a whole bunch of things trying to fix it, but if this is what is happening to you - I can see way you are having so much trouble. Every time I had this problem the prints would get all messy and then it would stop working. Now that its fixed, it only seems to happen with white PLA if I forget to enter the exact filament diameter in RepG before slicing and exporting the gcode.

[bart.s...@ichoosr.com]

Dear Mr or Mrs Makerbot,

If your biggest community (this group) has 1110 views on this topic ... Extruder problems Replicator 2 ... then you should come forward with an announcement.

Clearly something is wrong.

We know this, but we are also enthusiastic believers in 3D printing, and we have not dissed Makerbot, but you need to show a sign of life ...

Looking forward to your reply.

Bart

[bart.s...@ichoosr.com]

Rick,

I think acetone doesn't do anything to PLA?

Bart

On Tuesday, January 1, 2013 6:20:28 PM UTC+1, Rick Rogers wrote:

I've had the same filament feed problems and tried all the suggestions from Makerbot support.  What finally seemed to help was:

1. Adjusting the extruder plunger - tighter than as shipped
   
2. Changing filament (from the 1 pound spool to some other that I ordered with the Rep2)
   
3. Tearing apart the extruder, soaking the nozzle in acetone overnight.

Mine has been printing reliably for the last week or so after those adjustments...fingers crossed

[Chris Milnes]

I've read that it has 0 effect on PLA. 

But can't confirm first hand. 

--
 
 

--
======================
Chris Milnes  |   True9.com
======================
office: (201) 840-1303
cell: (201) 207-4163
email: chr...@true9.com
======================
facebook.com/muckychris

[whpthomas]

So I had a very interesting (read frustrating) day today trying to get a large component that took up most of the build plate to print. I was printing in WHITE PLA which is the colour I have been having the most trouble printing with.

Firstly I had problems with the first layer being inconsistent, so had to re-level the build platform. It really would be better for larger prints if the adjustment screws were right out at the corners of the build plate rather close to the middle. But after a bit of trial and error I got a good first layer to print.

Next I had the dreaded extruder stall - six times in a row, at 23%. Each time I tried something new to see whether it would resolve the problem.

First I decided to give tightening the plunger grub screw a try. Except this time I took the stepper motor out, inserted a piece of filament and tightened it until I could not strip it out by pulling on the filament and stopping the feed gear with my thumb. I then turned the feed gear manually to make sure it was still able to move without too much force. I basically adjusted the grub screw until it was as tight as possible, but I could still manually turn the feed screw without excessive friction of force. While this improved the consistency of my extruder - it did not fix the stalling problem. Clearly it was not an extruder feed failure.

Next I played around with both temperature and feed rates. This also had no effect.

So six failed prints later and a day wasted I was feeling rather dejected. I started looking over the failed prints. Interestingly enough they had all failed around the same layer. It was a a layer with a large solid infill followed by a long but very short zig-zag infill with a width of about 0.5 mm. After that the extruded filament was progressively inconsistent - although it was hard to pin-point which fill type caused it. So it seemed to me there was something about large filled areas on upper layers, or large tight fills where the nozzle is zig-zagging very quickly but not moving particularly fast that was causing my extruder to jam.

So I figured the easiest way to test whether this was the case, was to change the ReplicatorG Fill->Infill Begin Rotation to 45 degrees. This limited the size of the infill strokes, and changed the nature of the zig-zag so the nozzle was moving faster. Sure enough, print number seven using these settings worked.

Clearly there is something going wrong on some infills - at least on my Replicator 2 with WHITE PLA that is causing my extruder to back-up, clog and stall. It was repeatable and occurred on the same layer in the build. While this might be a mechanical problem, I suspect that the PLA is backing up and spending too much time in the nozzle chamber, which is causing it to go bad and clog. 

Seems the solution would be to change the flow rate for solid infills somehow.

[Rick Rogers]

I'd heard that too, but it did seem to clean up the nozzle (could be my imagination).  And again it could be my imagination, but it seems to make a difference if I wipe off the build plate with acetone before a build (better adhesion - maybe it's cleaning off stray oil from my hands?).  Or maybe I just like the smell :-)

Rick

[Joseph Chiu]

If changing the flow rate is helping prevent the jams, it might be that changing your extrusion temperature up or down might help.  My initial guess is down -- as your faster infill is heating up the filament less...  I've been struggling with filament jamming as well (I think I've got it mostly under control now) and have found blowing my bot with a room fan also helped tremendously.

--
 
 

[whpthomas]

So here is another example of a print failure where I had a large area of supported solid infills. I managed to fix this problem by changing the surface design to be flat, and adjusting the filament diameter to a larger setting, with a packing density of 1.0

So far I have 230 hours of printing under my belt, with dozens of large successful prints, it is only this WHITE PLA that is dogging me - my bin is full of it - and in particular failures on upper layers with large areas of solid infill. 

I bring this up for two reasons. Replicator 2 operators having extruder problems may want to try different filament - even from different suppliers - and also printing different types of objects. Clearly some objects are more problematic to print than others.

[whpthomas]

After a bit more playing around I am pretty sure the problem can be isolated to long duration but short in distance zig-zag infills. Like say a 4mm wide 100mm long wall - as the extruder does the crossways infill the head jiggles quite fast but doesn't actual move very fast. The slow extrusion is cooking the filament in the nozzle and causing it to jam. I am going to play around with the Inset->Infill width over thickness setting to see if I can correct this - anyone with experience with this setting?

[Andrew Plumb]

I'd double-check that this "WHITE PLA" is in fact PLA.  If you're able to easily dissolve it with some acetone or nail polish remover then I'd be more inclined to classify it as an accidental spool of ABS.  Wouldn't be the first time someone has ordered one material and gotten another.

Be grateful it wasn't HDPE or you'd be in a *real* mess. ;-)

Andrew.

--
 
 
<infill-print-failure.jpg>

--

"The future is already here.  It's just not very evenly distributed" -- William Gibson

Me: http://clothbot.com/wiki/

[Richard Wildey]

My Replicator 2 has developed the same annoying problem after about 140 hours of use and many great prints.  I thought it was color, but I have tried Black, Blue, White, Green, and Red all with results similar (Grey is the worst for some reason).  I get about 40% done a beautiful print and then it stops extruding.  I have done 35% infill, 10% infill, 100% infill, I have done temperatures from 220 to 260, I've leveled the build plate so many times my makerbot business card is worn out.  All 1.75mm PLA.  I have used ReplicatorG with defaults, and even Makerware with Grue defaults.

 

I'm going to continue figuring this out... but watching this thread with great interest.  The amazing thing is, my machine was great for about 125 hours... now this.

 

My Replicator 2 is great, but I'll be thrilled when this is solved.

[Eighty]

Everyone's results are different, as I have had resounding success with my white PLA. I'm starting to think that Andrew is right...maybe you got some ABS by mistake.
The short zig zag infills, by my reckoning, shouldn't cause problems with degradation. While the extruder may not be moving quickly, it is still discharging the plastic at a decent clip - therefore the filament doesn't hang around long enough to burn up. You would theoretically notice more of an issue on prints with lots of travel (and not much extrusion). If you're getting blockages with tight infills, it may be excessive back pressure.

[Dan Newman]

On 2 Jan 2013 , at 5:36 PM, whpthomas wrote:

> After a bit more playing around I am pretty sure the problem can be
> isolated to long duration but short in distance zig-zag infills. Like say a
> 4mm wide 100mm long wall - as the extruder does the crossways infill the
> head jiggles quite fast but doesn't actual move very fast. The slow
> extrusion is cooking the filament in the nozzle and causing it to jam. I am

> going to play around with the *Inset->Infill width over thickness* setting

> to see if I can correct this - anyone with experience with this setting?

No good experience with that setting. But I can give another thing or two
to consider

1. If it's a very small area for the entire layer, then the Cool plugin.
However, I doubt this is the case for your print: it looks to have a lot
of area in that layer.

2. The jerk control values. The XY "jerk" control which the MBI firmware
uses is likely dropping the speed way down in that infill. Increase the
XY jerk value or use line infill instead of rect. grid or hex grid.

Dan

[Joseph Chiu]

This seems similar in some way to my recent problem where jams were happening while printing an object that had small islands.  Jams were happening down somewhere in the hot end -- the problem seemed to have resolved with increased cooling.  One untested hypothesis I have is that the increased cooling leads to higher heat flow and better temperature regulation inside the nozzle (because the PID is dominated by air cooling losses which is constant, versus the filament cooling losses that varies with extrusion quantity) -- I think there must be some kind of dead man's curve in the temperature/flow rate/cooling rate curve...

Dan

--

[whpthomas]

Tested the white PLA with acetone - had no effect - so it is PLA. But the roll is coming to and end, so maybe filament from towards the end if the real is a bit more squished and inconsistent.

I played around with the width over thickness setting but no obvious benefit.

It is pretty hot here today, 33C (91F), and the stepper motors are heating up, all the stepper motors are quite hot to touch. I wonder if this heat is transferring through the drive gear to the PLA and causing problems. Going to run floor a fan blowing into my Replicator 2 and see how that goes.

[Chris Milnes]

Hi Richard, 

That exact scenario was solved with tightening the grub wheel that pulls the filament into the nozzle. 

It wasn't clicking or anything - just when i got at a specific point on the same print it would stop extruding. 

This may not be the prob you are experiencing but one more thing to try. 

(it's not the infill or temperature i would bet that) 

Good luck friend.  

Best, Chris 

--
 
 

[Richard Wildey]

Hi Chris,

 

I've done that too... watched the Makerbot support video, and I've adjusted it just right... plenty of pull when I hold on to it as it's loading.

 

Tonight I've done 220 Degrees, 230, 240 all the way up to 260 Degrees and the best print (readers will cringe in disbelief) is at 260 with the cooling fan off (yep off).  I live in Arizona where it is generally dry, not sure if that matters.

 

As I've said, the first 140 hours, brilliant prints... lately, not so much.  I'm beginning to wonder if the temperature readings are correct on the Replicator 2.

 

Rich.

[Joseph Chiu]

Well, the PLA will definitely not melt below 186, and will certainly be melting (though perhaps a bit thick) by the time you hit 200..  If you are 40 degrees off, I think you'd see that you can't melt the PLA at 200...

--
 
 

[whpthomas]

So I tried re-running my troublesome print with a fan blowing into my Replicator 2 to see if keeping it cooler would help. No luck - two failed prints. It was really annoying me. Lots of failed prints int he bin 

I can confirm that even a hot stepper motor is not hot enough to make the PLA go soft - so this is not an issue. It might if the heatsink fan was disconnected, but not just running normally on a hot day.

So I went back to my default profile, and this time tried the opposite. I went into the menu and turned off the build plate blower. I figured that because this is a big work piece, its no going to have problems with layers not cooling down enough.

Now, turning off the blower hasn't actually fixed the problem, but every time the feed gear slipping it clicks, and the machine is quieter now so  that I can here it as soon as it starts to happen. I just grab the filament and keep pushing it into the extruder until the flow resumes. This is a kind of manual fix, for extrusion failure, but at least I will get this part printed and out of the way and I can move on with other things.

It is definitely on the long small zig-zags where this happens - it gets 2/3 along and starts clicking. Very curious as to why it jams here, but at least this manual approach provides a solution. I suspect that the flow calculations for these small zig zag extrusions are wrong. Normally they just stalls the extruder, but because most of the time they are short in duration - there are no problems. However with a larger fill area the extruder feed gear strips and fails. Just a hypothesis, but I plan to design a test shape to see if I can repeat this error reliably - which may lead to a fix :)

[whpthomas]

OK so the last approach worked. Turning off the blower and manually feed the filiment every time the extruder stalled. Basically, I sat there for three hours, and every time I heard a click on the extruder I grabbed the filament and pushed away. It only happened about five times, but I am sure that if I had let it go the print would have failed.

Towards the end I turned the blower back on because the remaining islands were getting small and needed cooling to stop them from being uneven - by then the worst of the hazards had passed. Short zig-zags were the main culprit - not on every layer, but just here and there at random. Later I will make a custom object to see if I can reliably reproduce this problem. It would be interesting to see if it is a slicing error or a firmware problem. But it was very apparent that on some layers with these long runs of small zig-zag infil there was a lot of back pressure causing the extruder to stall - it was turning way faster than the filament could be extruded - even with me pushing down hard on the filament. I even stopped it a few times and did a unload/reload - but as soon as it resumed it stalled again and started clicking - there was just so much back pressure for the extrusion speed. I would like to isolate the gcode that is doing this and see if I can figure out what is going on.

My hypothesis is that there is a bug somewhere that is creating inconsistent flow rates causing short spikes of back pressure, and that most of the time these are insignificant enough that the extruder recovers. However if the grub screw not tight enough, or the filament diameter is inconsistent the drive gear slips, and if the back pressure lasts for long enough, it strips the filament and jams the extruder.

[bart.s...@ichoosr.com]

Henri,

And if you print @ lower speeds?

Would that solve the problem?

Bart

[John Watson]

well just installed the mk8 rep2 replacement part
and finaaly got a 3.5 hour print done with 0 issues..going to keep trying over the next couple of days and will keep everyone informed

[Bart Stevens]

Isaac,

It's on thingeverse.com

Bart

On Thu, Jan 3, 2013 at 8:07 PM, Isaac Budmen <ibu...@gmail.com> wrote:

Hey John- If you would, could you please point me in the direction of the mk8 rep2 replacement part are you referring to? Thank you!

On Thursday, January 3, 2013 1:54:03 PM UTC-5, John Watson wrote:

well just installed the mk8 rep2 replacement part
and finaaly got a 3.5 hour print done with 0 issues..going to keep trying over the next couple of days and will keep everyone informed

--
 
 

[Bart Stevens]

Henri,

I tried at 40mm/s, but no luck.

Got stuck at 45% of build.

Has to do something with retraction ...

Bart

--
 
 

[John Watson]

http://www.thingiverse.com/thing:35810
or this one
http://www.thingiverse.com/thing:36482

i made the top one :-)
cheers
john

 

--
 
 

[John Watson]

On Thursday, 3 January 2013 14:07:39 UTC-5, Isaac Budmen wrote:

Hey John- If you would, could you please point me in the direction of the mk8 rep2 replacement part are you referring to? Thank you!

On Thursday, January 3, 2013 1:54:03 PM UTC-5, John Watson wrote:

[John Watson]

sorry double posted
ps I am still printing after 4 hrs ..getting a few clicking noises but the extrusion is still good
lets keep our fingers crossed
I reckon if a spring was added to the plunger it too might aleviate the problem ..
but this is the most I have printed so far so I am hoping this is the case ..if anyone has done the mk8 replacement just make sure the srping has lots of tension ..or it wont work well
I went to princess auto and bought a box of assorted springs and found a good spring  and used that..but I still think the mk replacement could do with a minor mod to allow for tensioning a spring :-)
almost at the end of my roll now ..with more on order..but i Reckon makerbot ows me a roll of free filament ..and they should be making an mk replacement themselves and sending us a shiny aluminum one :-)

[WMc]

Hi John,

I made a mod to the Mk8 upgrade to include a tensioning spring when I made mine a few weeks back.  If you increase the hexagonal spring pocket (the mk8 upgrade which doesn't involve cutting the plastic cover) to 8.2mm AF then a stainless M6 head fits perfectly inside.  I cut the bolt down so it fit and used a locknut and washer to do the tensioning.  Works great but not sure it will be for everyone.  Simplicity and few parts is the key for most people I think.  I can post a photo of it later today if you want to see the finished product.  I used solidworks to modify the hexagonal pocket.

Cheers,

  

[John Watson]

That sounds great
would be great if you posted the finish I would love to see it
I have been talking to a friend who has a cnc milling machine and have asked him if he could make one up out of aluminum  which I think might be a less flexible solution heheh:-)

[Infinityplusplus]

I was going to set up the spring tensioner on mine to see if I could get nylon to extrude properly. It was wanting to slip a lot easier than PLA. I decided to try a stiffer spring first. I put on a jones c12-041-040 spring and was able to get both PLA and nylon to print without slipping. Also switched in a 10mm bearing to test. Working good so far. I did have to modify the springs diameter at the base a tiny bit to seat it, if it works I'll fix the part to make it fit correctly.

[John Watson]

well I finally got a response from makerbot and this is it ..I am stunned and completely disappointment as to the reply as it was completely useless
check this out

 

Hi John,

Again, I'm sincerely sorry for the delays; between holidays, an office move, and extremely high ticket volume, though, I'm getting back to everyone as quickly as I can.

I'm very glad to hear that you're doing alright with the MK8 Replacement. I have heard very good things about this design. If you plan on reverting to the original design at any point, feel free to re-open this ticket and I'll be happy to continue working with you.

 

what the hell kind of response is that ..there was no way I was letting them off the hook  as I had written a novel on the issues  and only told them I had made the replacement part out of frustration
why the hell would I just let it go after putting on the replacement and getting prints ..I wanted solutions from makerbot ...and all I got was this lousy tshirt of an answer

now I am really annoyed