Re: Can't print PLA on 2X, loads fine but won't extrude on print, need suggestions

[Eric Weber]

Hi,

I have the same issue with the MB PLA (also using yellow).

It works for larger areas first - I need to push the filament by hand initially when the printer starts as it will otherwise block the nozzle right away - but as soon as I get to finer areas I have the same issue as you.

I believe the issue here is heat creep combined with the PLA composition MB uses.

The PLA simply get's soft all the way to the extruder - the hot end of the 2X does not allow for sufficient cooling.

There are plenty of discussions here in regards to this matter.

I have finally been able to print PLA on mine using PLA from China with a slightly higher temperature range and using a fan to blow into the 2X compartment (door open, hood off) to cool the PLA after it leaves the hot end - else the material will "jelly" around and will be pushed away by the extruder on the next pass.

Currently printing with 220C and the HB at 60C (Kapton Tape).

Print Quality however is far from ABS so far. The missing active cooling at the tip is a real issue I believe.

Maybe try with lower temps and blue tape instead.

Good luck.

[Carl]

I'm curious... if you switch off your HBP... and up the extruder temperature to 238 deg C... do the results get better or worse?

[Eric Weber]

I would need to test it out. My guess is that it will get worse. I nees the HB to get the first layer to stick. Without I assume it will come off easily.

Also increasing the temp will worsen the heat creep and increase the "jelly"  effect as the PLA needs an even longer time to cool after extruded.

I actually planned to reduce the temp further and use blue tape, HB off, and see what that does.

On Jun 10, 2013 5:52 PM, "Carl" <cpra...@gmail.com> wrote:

I'm curious... if you switch off your HBP... and up the extruder temperature to 238 deg C... do the results get better or worse?

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[Carl]

Give it a try... I am sure it will be worse... but I would like you to confirm this if possible... the HBP needs to off for this test... so try some blue painters tape/hairspray and power on through - even if the first few layers are a mess...

[Carl]

What is the ambient temperature where you are and weather conditions?

[Count Spatula]

Do a search for 2X PLA and you will see we have had no luck printing PLA on the 2X. It just won't do it. Until someone in the community comes up with a hack stick to ABS.

[Damian Gto]

That's not true. Me and other print PLA. So it can be done. The big issue is the heat and you must take care of that.

[Eric Weber]

Damiangto, can you provide more details on how?
What's your setup, temperatures and modifications? What PLA do you use?

Thanks

On Jun 10, 2013 9:44 PM, "Damian Gto" <dami...@gmail.com> wrote:

That's not true. Me and other print PLA. So it can be done. The big issue is the heat and you must take care of that.

[Count Spatula]

Damian, I should clarify.  I have been able to print small items such as the calibration cube but even then most of them fail. On my ToM I can print anything of any size with PLA but with my 2X I can't print anything large and small items do not print reliability or repeatability.

Have you had success printing large items and have you been able to repeat small or large items reliably?

I'm not being sarcastic,
Sean

[DHeadrick]

I have a Replicator 2, so I can't really help you with settings.  I can tell you that those bits of PLA filament that you have pulled out of your extruder look very typical.  My printer works fine with PLA and when I unload the filament, it looks like that at the end.  Just thought you should know that it isn't abnormal looking.

[Eric Weber]

Not working. The PLA will not extrude when printing. 

The higher temperature makes the PLA soft and the extruder slips :-( Same issue as with the MB PLA at 220C

[Eric Weber]

The 2 and 2X have a completely different head design in addition the rep 2 has a active cooling fan just for the purpose of cooling PLA.

Hence I believe both are not comparable and lessons learned from the Rep2 will not apply to the 2x.

I believe the 2X can work with PLA provided:

1. The hot end is updated to shield the filament closer to the extruder motor better from the heat (maybe retrofit the rep dual head...)

2. A cooling fan is added to the nozzle of the 2X (check out the design, work in progress, on thingiverse)

[DHeadrick]

I'm not saying they are comparable.  I am saying that his PLA filaments which he removed from his extruder are typical.

[Carl]

It proves that it is heat creep...

The price you pay for easy nozzle height adjustment on the 2X is that you can only print ABS reliably...

[FDP]

The Replicator 2X cannot reliably print PLA - period. I have spent a great deal of time trying to get this to work, and finally got MBI support (and sales) to admit that they can't get it to reliably print PLA either. The reasons are stated above in the thread, so I won't rehash them. If you want to print tiny objects with PLA you might be able to get the 2X to somewhat work. 

What is unfortunate is that certain MBI support reps claimed that someone in-house was printing PLA "without a problem", on the 2X, which turned out to be incorrect.

Bottom line, MBI has not bothered sending out an e-mail update re: PLA on the 2X, or posting to this forum. They seem content to let the 2X users eat up their time struggling with PLA.

[JohnD]

Chris Milnes has repeatedly said he has no problems printing PLA out of his 2x, of course you have Damien GTO as well, and I can absolutely, positively tell you that if you call MBI to order one today, they will *still* tell you you can print PLA on it...

The above said, I can't make it work consistently. 

[FDP]

I would greatly appreciate Chris or Damien elaborating on how they print PLA, and maybe what size/types of objects they can print. It would be incredibly helpful to hear from someone directly who actually has success, and get as many details as possible about how they succeed, as so many of us have zero luck with PLA on the 2X. 

I spoke with MBI support a week or so ago and finally got the admission about PLA. The trick is to use the word "reliable". Yes, the 2X *can* print PLA. Can it print reliably, absolutely not. I was always told that there was someone at MBI who was printing PLA on the 2X, but when I asked to be put in touch with this rep. I never was, and eventually was told that they were also having issues. 

It doesn't have to be this way. Users should not be wasting their time on things that MBI can't even get to work, and we shouldn't be coordinating the efforts to get their machine working. This community was part of the reason I picked up my 2X, but I feel like MBI needs to put in a lot more effort mining the fantastic resources that users such as Chris & Damien offer. If either of them can help 2X users print PLA then I would hope MBI would send a few reels of filament their way, along with a thank you on the blog!

[TaErog]

I am one of those that can print PLA on there Rep2x . .  

" elaborating on how they print PLA" is nothing outstanding at all and no secret (and not about to go over it again here - do a search )

It IS possible . . there is physical evidence really!  What people mean by consistent? is all over the place it seems.  I have printed large and small prints a few times (as I do not like PLA for allot of my prints I do not print "consistently" with it.)  I have not need or want to print more, but have demonstrated that I can easily print large/long prints in PLA

this does not mean that it is as fool proof as using a Rep2, it IS easier to set a rep2 going . . But a bit harder is a FAR cry form you categorically can't print PLA on a Rep2x !@#

And I think this is the real rub! you really need the 2x printer dialed in to work well in PLA.  There is allot more latitude for error on the rep2.

Knowing this and knowing the potential problems it is not hard to mitigate them and get printing.

so if you have a heat problem . . . . .

 

Add cooling!  My prints worked because I have dialed in the temp for the PLA I have (lowest that worked +1 or 2) and then put a desk fan blowing on the printer!  (top off, front open etc)    And I did NOT use the HBP at all . . just tape.  (also some colors behave differently so factor that in)

So if you are not supplementing cooling in a big way . .you are doing it wrong :P

 

This is really not that hard . .

[Joel Edelstein]

TaErog, 

  I appreciate that some users have things working. I *have* searched and read most everything anyone has to say on printing PLA on the 2X on this forum.

The problem is there is nothing scientific about this, and Makerbot themselves cannot print reliably or advise users on how to do so.

It is never helpful to say "I'm not going to elaborate". You threw in a decent amount of text, but what would be nice is actual numbers. What is "lowest that worked"? For me that was 210, but others can go lower (and PLA should be able to go down to ~180). Perhaps ambient room temperature and humidity are important? I am running at 70 degrees F and 47% relative humidity. 

What is reliable? Better than 3 in 10, which is my error rate with small parts in PLA. I personally find that a cold machine (one that hasn't been running) will print better than one that has been going for a few hours. I have 0% success on anything in the 100mm x 100mm x 50mm size. I find that the filament jams reliably, meaning that is jams 7 out of 10 times or more.

I am using the same general setup as you (top off, front open, house fan, no HBP, Blue Tape). I've used natural PLA and red PLA from Makerbot. 

It is *really* that hard for me. Why? You can't say, and I can't say, but claiming that because things work for ~4 users out of 100 = "not that hard" is not very helpful. I am sure you have a great deal of experience that would be very helpful to newer users such as myself, but try your best to put yourself in the shoes of somehow who isn't having your experience. 

Let's work together to figure out what makes your setup work and mine fail. 

--

[TaErog]

Sorry on being short but After 3-4 times typing the same thing it gets old.

 

On that, the temp . . now I never gave temperatures as quite frankly it would be misleading.   My white PLA is very different from the natural, and I know from experience the temp the bot is displaying is not 100% accurate.  given just these two variables and I can probably thing of more the temp ideal temp you could be using would be different then mine . . That and given the cooling I added I do not think my numbers would do anything but mislead people from doing what they should and finding the correct temp themselves.  (Now doing that is something I looked up and researched from annotated photos of PLA print results vs temp and known feed problems I knew what to look for so I could calibrate.

My room temperature and humidity is similar to yours so those variables are at least not in the running.

 

reliability?  you asked the correct question, to define my meaning of it!  What I found was initial set up was everything here.  Jumping from test cube that looked more or less ok to larger print failed bad.  Making sure a test object was really dialed in (amount of material used, speed, temp, overhang tests etc) - there are allot of good ones on thingiverse (I do not use the cube for anything but a "in the ball park" print) Then printing larger objects was relatively easy.  Say 3-4 of 5 . . but this is where my sample size may start to suffer as I printed some large objects that all worked (strangely the some medium ones failed? but at least one was my fault etc). . and then went "Meh" it works fine.  (and I did say that above to let people know I do not print in PLA all the time, so should have had MORE problems?!) . . I would think the hand sized octo that has allot of volume and too a good time printing would have been the worse of the group given known PLA heat buildup with large and thick objects. but no problem.

 

I really do not know what to say,  I can't know how technical you are, now "in tune" you are with your printer, what quality your plastic is or is in (I keep mine is plastic bags with desiccant). if your printer is working well and calibrated, what slicer you are using, what FW, what settings. etc  and even if the less general things are shared "settings" "temp" etc they do vary per printer, slicer, and plastic.

So all I can legitimately do is give general advice on the bigger aspects. 

See the problem?  I do not think a few numbers here is the problem. and since the rep2x IS more finicky with PLA you have to have all of these "ducks" in a row or any one of these could cause problems.  The rep2 you could be a bit loosey on a few and it would basic still function if not well.

I say try again,  print with a raft (so that is not a variable), print at .2mm .27mm or more before going down farther. MAKE sure you are extruding the correct amount of plastic!! Keep all of it cool!.

 

Now, interestingly enough . .  I noticed that the prints I did use repg with (I moved on to Simplify3D creator) I did NOT use the PLA setting in the profile. (Repgv40 sailfish) as when ever I did I got strange behavior.  so I modified a ABS profile I was using (changed packing etc) and it worked much better.  . . a potential difference? ??

 

 

 

 

[Count Spatula]

TaErog - 
I totally agree that you need to take the time to know your machine, dial in the settings, etc, and, yes, the 2X is advertised as experimental, BUT the PLA profiles in MakerWare should be able to get you a decent print. I have not found that to be the case.  Once again, I was able to get nice PLA prints off my ToM with very little fiddling, you would think that this would also be true for their newest printer, especially since it's predecessor was optimized for PLA.  It seems like there are exponentially more people like myself who can not get the 2X to print PLA than those that have.

[TaErog]

But other then the Repg bug I ran into, I kind of doubt it is a slicer problem (could be wrong though) . . the problem is the Rep2 is optimized for PLA and the rep2x is optimized for ABS.  (read [hardware] is optimized for  . . ) "since it's predecessor was optimized for PLA"- Count Spatula  I agree totally - but you forgot the second part :)

 

So take that from face value you can get both to print the opposite plastic, but by default they are not setup to do it and both require help. (ie there is NO fan on the rep2x not even a small one . . so seriously how can anyone expect that to work?  and the nozzle is more prone to heat creep so need to keep cool! . . . same with the rep2 there is no HBP so you have to do something else to get ABS to stick and keep it warm). . . both are easily done even without modifying the printers greatly but they where not going to do it without some changes.

 

"BUT the PLA profiles in MakerWare should be able to get you a decent print" - Count Spatula   I could not disagree more . .  there are hardware design differences that make both less capable to do the others job as well as the other. (you state this clearly in your post)

 

I think the expectations are all wrong here . . you can print in the other plastic [and can with only some minor changes] is different, then you can just select a different profile and go.  (note that this is STILL DIY territory and if you are not having fun modifying your printer you are missing out on allot of the fun using them)

But if you expect either to be as optimized and good at printing what the other is made for . . I am not sure that is a reasonable expectation to have. (again harder <> impossible or not useful)

Hell on my old TOM I had to print a fan shroud/blower to get PLA to print well (without heat problems),  I expected and accepted that as the material demanded the change, why should this be different?

[Carl]

The problem is very fundamental... the heat from the heater block is traveling up the thermal barrier and into the aluminium cooling block... by that point the aluminium cooling block should dissipate the heat and assist in cooling the thermal barrier.

This is meant to happen so that the filament reaches its 'liquid' state as close to the nozzle as possible - allowing the filament that hasn't melted to act as a sort of plunger pushing the 'liquid' state filament out of the nozzle...

In the 2X... the PLA is reaching liquid state almost as it enters the thermal barrier... therefore no back pressure and therefore no printing...

Software settings may help... but I think the few people that are successfully extruding PLA on the 2X are only able to do this due having (apparently accidentally) found a sweat spot that is allowing the thermal dissipation to occur enough to allow printing to occur...

[Damian Gto]

I believe why we can get our rep2x to print PLA is for we take care of the heat problem. Post after post I read people do very little about it. Also I do not believe MBI did any modification when they tried. I'm sure it was stock.
What I did was to add more cooling where the nozzle is and then cooled the filament. I also had no lid and the front open. My sides was still in place. I used 210degree and makerware medium settings at first for PLA. After that I used a custom profile based on Abs. Only changed what was needed for the PLA.
Made some calibration test prints.
Then I did print some random stuff as long a had PLA filament. I did not had a full role..
I did not had any air print or broken prints. Only the first few test prints was bad, but after that they was Okey.
After that I did not print any more PLA stuff. I do have a full role of PLA now. I did not plan to print more PLA for I use abs, as what the printer is made to work with.
But I will see if I can repeat what I did and make some design for it. I'm sure you need 2 more fans to make it work.

[TaErog]

I agree and think you have the main and obvious problem (though I think if people are not carful the little problems complicate the tests and may even foil a good test)

 

. . .though "but I think the few people that are successfully extruding PLA on the 2X are only able to do this due having (apparently accidentally) found a sweat spot that is allowing the thermal dissipation to occur enough to allow printing to occur..." - carl

I take issue with "apparently accidentally" :P  I am very meticulous and I found possibly the "sweet spot" from carful work.  But I get your meaning.

Also I think we went overboard on cooling . . this alone may make the "sweet spot" much more manageable!

It is good that people are being active now in trying to make it work then just saying "can't"

 

Another parameter I was looking at is I reduced the amount of retraction, I did get a bit of dribble but not much . . may have helped by not pulling warm/hot filament up as far?

 

I was looking at my parts pile . . being a PC gaming rig builder/moder I found some old cooling parts I had laying around. . a Peltier and a homemade water cooler.   The water cooler was well, rather big so not useable here but the concept it still good. the block needs to be lighter then what I have - the tubes would have worked great.  But the Peltier can be mounted on a heatsink easy and can actively cool the block let alone chill it :) . . overkill but fun overkill.

 

Still looking at a blower fan with a corrugated tube that will cool the block and provide air for the extruded material as the real upgrade  . . .  may kill both birds with one stone and it does not need to be mounted ON the print head. (easily removable for when I am not printing PLA) and cools the top of the head, block, filament etc and provide solidifying air under the nozzle.

[Carl]

No offence intended! :-) There must be a solution that is verifiable and repeatable!

I wonder if my AluCarriage Dual would assist with dissipating the heat... When printing Nylon at around 260 deg C on my Rep 2 - the aluminium cooling block is cool to the touch... The is due to the heat sink properties of the AluCarriage...

Has anyone who bought one of the initial dual units from me tried to print PLA?

If it does not help... the only other solution I can think of is a redesign of the thermal barrier to match the MK8/Rep 2... I think the current design does not allow a smooth thermal flow into the aluminium cooling block...

[Jetguy]

Carl,

No, your carriage won't "fix" the thermal issue at all and here is
why.

The 2X is different from previous extruders in that the thermal
barrier tube is no longer threaded into the mounting block. Threads
have more surface area for conduct heat away from the tube and into
the block to be disipated. The real kicker about the 2X is they
machined away a lot of metal away from the thermal barrier tube
mounting hole to make the clamp system. This alone could account for
the problem. The heat is never transfered from the thermal barrier
tube to anythign but the filament. There is not heat in the mounting
bar to disipate to the aluminum carriage.

Therefore, if you wanted to help witht he problem, simply make 2X
mounting bars tapped M6 instead of smooth bore and use bone stock
threaded Replicator 2 thermal barrier tubes. Problem solved.

[Jetguy]

Point being, Replicator 1 hotend and mounting bar/thermal barrier tube
has NO PROBLEM with PLA or ABS.
Replicator 2X, totally resdesigned those parts and now has problems
with PLA.

Pretty simple really, we learned this game before age 5, "which one of
these is not like the other".

On Jun 11, 11:58 am, Carl <cpraf...@gmail.com> wrote:

[Carl]

Oh... like the one I sent you to review 3 month ago! :-)

[Joel Edelstein]

The fan position might be causing the warping.

On Jun 11, 2013 3:04 PM, "David McInnis" <cir...@gatohaus.com> wrote:

just chiming in...

Rep2X, PLA printing seems to work good so far.
I started with a combination / sloppy average of everyone else's suggestions and my first couple of prints have come out well.

Using MakerWare 2.1.0.20

Ambient enviro:  66F 35%RH
No hood (hasn't arrived yet),  front door fully open, sides attached,  120mm fan pointing from above at left-center of extruders.

Settings under 'Medium':

Infill  15%
Shells  2
Layer  0.27mm

Extruder  210C
Platen  55C     (stock kapton tape)

Ex speed  50mm/s
Travel   80mm/s


The only issue I see is that some corners are slightly warped upwards for the first few layers.  
Guessing they're not sticking well enough..  will try upping the temp a bit or dropping the initial layer speed.

[Damian Gto]

It don't help to say to people they need to rebuild the rep2x to a rep 1. You keep doing this. Try to help to solve the heat problem some has problem with.
As some of use CAN print PLA just show the problem is not where you say.

To me it's clear that you NEED to cool the filament, like I did write even before I did own my rep2x.
Also you NEED to cool down when printing.
This did work for me.
So if it was the problem you say it should not worked for me or others.

[Jetguy]

I simply replied to Carl asking if his aluminum carriage would assist
with the heat soak problem.
I answered with technical details to a technical question. You once
again, jumped all over my post proving you have a serious problem with
anything I post.

Damian, your response helped not one single person on the planet.
At no time in this thread did I say you HAD to upgrade the extruder. I
simply stated FACTS as to what fits and what doesn't, and how a person
would change it if they wanted to.
What is wrong with that? It was in response to a question, quit acting
like I forced it upon someone.


From the movie Billy Madison:
Mr. Oblaski, Principal
Mr. Madison, what you've just said ... is one of the most insanely
idiotic things I have ever heard. At no point in your rambling,
incoherent response were you even close to anything that could be
considered a rational thought. Everyone in this room is now dumber for
having listened to it. I award you no points, and may God have mercy
on your soul...
http://www.youtube.com/watch?v=5hfYJsQAhl0

[Damian Gto]

You keep saying this every time people say you should stop with it.
You keep bashing the rep2x on everything. None of them you have any experience with. You keep telling owner of the rep 2x what they can and can not do and what problem they have. Face it, you do not know. You are wrong most of the time.
Also I DID write what I did to make the PLA print to work and what the main problem is. I guess that is helpful?

[Carl]

And how has what you've just posted relevant to the topic???

Here is a special little post for you to continue...https://groups.google.com/forum/#!topic/makerbot/Dq34C_XjDHk

[Damian Gto]

I guess as much your post did ;-)

I do have an idea that might solve this PLA problem without to add more fans. It might be enough to use the two that is mounted already and use the airflow from them. I need to come home and try it first and make a design for it.

[Jeffrey Birt]

I took the left extruder off one of my 2X's to see how it was put together. One thing that surprised me is that no thermal compound was used on the feed tube to aluminum block connection or from the aluminum block to heat-sink connection. The surface are of the contact between the aluminum block and the heat-sink is also rather small. I put a small amount of heat-sink compound on both areas, put it back together and told the machine to preheat both extruders.

 

After about 15 minutes of heating the temperature at the top of the left tube is about 32C and the right tube is 35C. the temperature differential has been in the range of 2C-4C over the ten or so times I have checked it. The temperature at the top of the heat sink is 30C on the left and 29C on the right which also helps to show that more of the heat is being transferred from the tube to the block to the heat-sink. 

 

I'm starting a test print now to see how the left side does. I have found the nut/bolt sample to work well as a test as it seems to fail about 80% of the time so any improvement should be apparent (I hope.)

[Jeffrey Birt]

On the replicator 2 extruder design - does the active cooling fan blow on the nozzle or the build platform/part? It seems like if you let the machine set for more than 30 seconds after loading, the filament will get cooked/overheated at the nozzle and cause a clog. I'm wondering if that is what the active cooling fan is all about.

[Jetguy]

The blower is all about blowing on the printed part not any part of the extruder except near the nozzle. It could be modified but the hotend on a Replicator 2 doesn't have this problem.

You can see the duct here:

[Jetguy]

The front fan blows on the heasink just like the 2X. The blower on the left is ducted to blow at the build plate around the nozzle.

It could be modified with a hole and bloew across the top of the heater block at the thermal barrier tube. Simply cut the cut with a hole in the right spot.

[Jetguy]

http://www.thingiverse.com/thing:46343

Alternative http://www.thingiverse.com/thing:73827

 

But again, those are for a Replicator 2, they blow on the part/bed, not the thermal barrier tube.

[Jeffrey Birt]

Thanks for the pictures. To me it looks like the active cooling fan (one on left) on the Rep2 is there to blow on the nozzle, the 'V' shape around the nozzle would direct the air around it. I still suspect it is to keep the PLA from 'cooking' in the nozzle. The temperature of the thermal barrier tube was not an issue from what I could tell, at 30C it is just over room temperature. The heat sink paste helped a little, but I don't think it is really needed.

 

I guess the next thing to try is to direct some air over the nozzle itself. I think on the 2X it would have to be done from the front as it looks like with the two extruders there is no more room along the X axis.

 

I'm tempted to order a complete Rep2 print head just to see how it is made. What I should have done when we ordered two machines was to get one of each instead of two 2X's.

--

[Jeffrey Birt]

BTW, if the little tube is a 'thermal barrier' why is it made out of metal? It seems a ceramic tube might be a better choice.

[Jetguy]

One word says it all= Cost.

[JohnD]

I think it's stainless, which is actually a pretty decent thermal barrier in the world of metal. 

[Josh Jones]

Just for the record, I wanted to add that I too have a 2X, and it prints ABS fine, and I've never been able to get it to complete a non-tiny PLA print without the extruder getting jammed (I tried a lot of different extruder temps and have blue tape + non-heated bp + door and top open).. sigh!

I don't really like PLA anyway though! :)

[how]

Hi all, got a similar issue with PLA with my REP 2. 

Loads fine but stop extruding during prints. It cant even finish a single layer now. 

Contacted MBI but so far it's a guessing game. 

Things i have done for the past 4 weeks to fix this. 

-Change new nozzle

-upgraded to mk8 (constant compression on filament) 

-level build plate

-fully clean all extruder components.

-put thermal paste in thermocouple hole

-External check on extruder temperature and it matches the reading on rep2. 

-kick a few times

-tried diff temp from 200 - 245 degree C. 

-swap to replicator G

-swap to personalized print profile and adjust filament dia for each print

-revert back to makerware and use medium profile 

-kick a few more times. 

-increase compression on spring (helps a little but still cannot complete first layer of print and clicking occurs) 

-further increase compression on springs (print until 2nd layer with constant clicking). consequences of this is my base plate is ruined as PLA stick to plate like cement and i have to send it for machining.

-making a new stainless steel base plate. (yet to try this)

My next solution is to remove the heat sink and allow fan to cool the aluminium block and filament directly.

Hope the gurus can also help me out here. 

Thanks alot!  

[Carl]

how... Could you post a picture of your extruder? just of the aluminium mounting block down to the nozzle - preferably removed from the carriage (2 screws under the carriage need to be removed)...

Not too sure about thermal compound on the thermocouple... but I can't see it causing your problem unless it affects the temperature readings...

Before doing this... can you get the extruder up to around 230 deg C and let me know if the aluminium block is cool to the touch or very hot by touching the side of it...

[Eighty]

How,

Pictures of the failed prints (and your extruder) would be most helpful in solving your issue.  I see that you mentioned a few profile tweaks, but did you change the big one (Filament Packing Density)?  For PLA, it should be 0.97-1.0  If you're using the default RepG setting of 0.85, then you're probably overextruding.  Makerware had even worse settings (but they've improved the defaults in 2.2.0.46). 

[how]

@carl

i have attached the pictures as requested. hope you can spot something unusual and direct me again. 

When i first received the printer, i noticed the thermocouple was loose and during printing, the temp fluctuate often. After adding the thermopaste, temp became very stable. 

i set the heater at 230 D.celcius and let it stay heated for 20 - 25mins. I assume the temp should be stable and the side of aluminium block felt very warm. Still able to touch tho. 

@eighty

i downloaded the customised profile from http://www.thingiverse.com/thing:38390

i assume the  density is 1.0 according to the description. 

Still waiting for my base plate to return from the machine shop before i can do anything. 

cheers. 

[Dan Newman]

On 14 Jun 2013 , at 7:06 AM, how wrote:

> @carl
>
> i have attached the pictures as requested. hope you can spot something
> unusual and direct me again.
>
> When i first received the printer, i noticed the thermocouple was loose and
> during printing, the temp fluctuate often. After adding the thermopaste,
> temp became very stable.
> i set the heater at 230 D.celcius and let it stay heated for 20 - 25mins. I
> assume the temp should be stable and the side of aluminium block felt very
> warm. Still able to touch tho.
>
> @eighty
>
> i downloaded the customised profile from
> http://www.thingiverse.com/thing:38390
>
> i assume the density is 1.0 according to the description.

If it's PLA, then a filament packing density of ~0.95 - 1.00 is
apt. If it's ABS, then you're looking at smaller filament packing
densities -- around 0.85. But, as the subject contains the acronymn
"PLA", yes 1.0 is in the ballpark.

Dan

[Eighty]

How,

Not sure that this is pertinent to your issue, but where is your lower fan duct?  Did you remove it for the pictures, or do you not have one?

 

Reading your original post again, it sounds like your motor doesn't have enough strength to overcome something.  Clicking of the stepper means it can't do it's job.  There are a couple of possibilities:

1.) Too much friction in the filament.  Could be that your inlets aren't lined up well enough.  Can you manually push/pull filament through the entire extruder assembly (when turned off)?

2.) You could be trammed too close to the build plate.  If you can load filament ok, but it won't feed on a first layer, this could be the issue.  And since you mentioned that the plastic is sticking so badly that you have to get the plate machined, then it suggests you're printing way too close to the build plate.  You might try backing off just a hair to let the plastic exit the nozzle a bit more easily.

3.) I noticed that your heater block is turned at an odd angle.  May be nothing, but can you verify that it's tightly installed?  It should NOT spin easily.  If it does, then your thermal barrier tube may not be butting the nozzle.  That would definitely cause problems with extrusion.

[how]

yea i removed the fan. the fan is there during printing.

1) yup, i can manual push/pull filament when i removed the stepper motor with heater on. without heater on, just running the filament it becomes very tight and need to use a fair amount of force. 

2) ok, i follow the level build plate guide and there shld be a 1 mm gap. i can try giving it a bit more space there to see if it works. 

3) i received the printer with the nozzle turned at an angle. i just follow this configuration ever since. it is tight and the thermal barrier tube is touching the nozzle.

what you suggest to reduce the friction? i have tried fighting against the stepper during extrusion by pulling the filament and it wasnt easy. 

thanks.    

[Eighty]

Hmm, something doesn't make sense.  You said you're tramming with a 1mm gap - I hope you meant a 0.1mm gap.  That would be much closer to the intended ballpark.

 

So to your first item.  If you're not having any problems moving the filament back and forth WITH THE STEPPER REMOVED, but it gets very tight when installed, then your extruder may not be mounted in-line with the thermal barrier tube.  It'll be difficult to check, but you need to somehow verify that the outlet of the extruder mechanism feeds filament directly downward into the thermal barrier tube.  If they're off, then your stepper may be fighting it - resulting in clicking.

 

If your alignment is ok, then there are other avenues to check.  In fact, I'd recommend walking through your entire feed system to look for anything that increases drag.  Does your spool turn freely?  I use a bit of Vaseline on the inner surface of my spools to reduce the turning friction.  Is your spool installed so that the winds come off the bottom, and feed directly into the guide tube?  Some people have installed it the other way, where a hard bend is required to get into the guide tube.  Have you cleaned your barrier tube and/or nozzle?  While it may "load" ok, the additional backpressure when printing might be overcoming the total strength of the stepper.  And lastly, as mentioned above, being trammed too tight would increase the back pressure.  Sometimes, a combination of "a little too much here" and "a little too much there" will add up to overcome your stepper.

 

Failing everything else, there could be some voltage issues with your stepper.  If your connection is loose, or if you have dirty contacts, you might be losing power. 

[Eighty]

Oh, one other thing.  When I asked about your lower duct, I didn't mean the fan itself.  I was asking about the elbowed plastic duct that vents air to a forked outlet at the nozzle itself.  Just making sure that you have that piece (some people received printers missing that part). 

[Carl]

How... based on the images you posted... I would say the first potential problem is that PLA seems to be leaking though you nozzle thread at the point were it connects to the heater block... This would explain the problem you are having...

I see that your nozzle, heater block and thermal barrier are rotate about 45 degrees... Have you taken these parts apart before? My recommendation would be to strip, clean and rebuild the whole assembly... If you haven't done this before... let me know and I'll walk you through the steps... I have done this many times on my machine! :-)

[how]

@ eighty,

Sorry that was a typo, 0,1mm gap is correct. 

I printed the extruder upgrade in PLA awhile back. The prints was ok for 2 weeks or so. I know a lot of users do not recommend PLA for the extruder upgrades but i do not have excess to ABS and shipping is crazy. Furthermore, the aluminium block is only warm and able to be touched thus i believe to a certain point that the heat is not melting away the mk8 upgrade. oh well, i just have to trace the alignment issue with the feed mechanism. Spools are placed correctly so no issue on that. i have cleaned the nozzle and barrier tube. Placed them in the stove and cook them till all crap was melted. 

I am also under the impression that the voltage might not be sufficient during printing. Can guide me on this? what should be the voltage during operation and which point to take reference. 

@carl

i will check on the leakage. 

yup i have taken all the parts out before. i have clean them about 10 times till date. 

The heater block, thermal barrier and nozzle came in 45 degrees so i assume that is the original position. i tried shifting them straight but the carriage wont fit due to the thermocouple wire and heater wire. 

sounds like my original setup has a slight difference with you guys. i am wondering if i received a beta kit.... hmmm..  

[Eighty]

Ok, the fact that you've reinstalled the thermal barrier tube and nozzle (multiple times) could be a factor. You MUST ensure that they butt up to each other properly, or you'll get leakage and, inevitably, jamming. I would focus on that.

The other focus would be your printed upgrade. If you had good prints when it was new, and they're not so good now, that could be the issue. While the block may be cool, keep in mind that 230c air is constantly wafting upwards into the PLA parts. I noticed a small gap in your upgrade parts, at the base of the lever arm. That probably means it is deforming. Also note that the arm is hitting your overhead shroud. Also a sign if deformation. You might try printing another one for now. Just put a big fan blowing directly onto your gantry to get you through the print.

[Carl]

To assemble the nozzle, heater block, threaded rod and cooling/mounting block:

I screw the nozzle into the heater block (to my desired height) by hand. I then take the threaded rod and screw the short threaded section into the heater block until they touch - I then take the assembled parts, add a nut and then thread the longer threaded section of the threaded rod through the aluminium cooling block. When it comes out of the other side, I line the heater block up and then add the second nut and lock the two nuts together. I then reconnect the heater and thermocouple.

Once everything is in place I tighten it all up (gently).

You should have plenty of space for the thermocouple and heater wires once in place... turn 90 degrees to get through the carriage opening and then rotate back into place once though the opening... Although if everything is put together properly... it shouldn't be a problem to have it at 45 degrees... just be careful to make sure that the heater element is not too close to anything...

[Eric Weber]

Hello TaErog,

I see that you are using Simplify 3D now.

I'm currently evaluating the SW and was wondering whether you could pass me the 2X profile you are using?

I did adapt the Rep2 profile that came with it but can not get the left extruder to work at all and have some gaps between layers if print with the right one and leave the layer overlap <35%.

Thanks !!

On Tuesday, June 11, 2013 3:35:43 AM UTC+8, TaErog wrote:

Sorry on being short but After 3-4 times typing the same thing it gets old.

 

On that, the temp . . now I never gave temperatures as quite frankly it would be misleading.   My white PLA is very different from the natural, and I know from experience the temp the bot is displaying is not 100% accurate.  given just these two variables and I can probably thing of more the temp ideal temp you could be using would be different then mine . . That and given the cooling I added I do not think my numbers would do anything but mislead people from doing what they should and finding the correct temp themselves.  (Now doing that is something I looked up and researched from annotated photos of PLA print results vs temp and known feed problems I knew what to look for so I could calibrate.

My room temperature and humidity is similar to yours so those variables are at least not in the running.

 

reliability?  you asked the correct question, to define my meaning of it!  What I found was initial set up was everything here.  Jumping from test cube that looked more or less ok to larger print failed bad.  Making sure a test object was really dialed in (amount of material used, speed, temp, overhang tests etc) - there are allot of good ones on thingiverse (I do not use the cube for anything but a "in the ball park" print) Then printing larger objects was relatively easy.  Say 3-4 of 5 . . but this is where my sample size may start to suffer as I printed some large objects that all worked (strangely the some medium ones failed? but at least one was my fault etc). . and then went "Meh" it works fine.  (and I did say that above to let people know I do not print in PLA all the time, so should have had MORE problems?!) . . I would think the hand sized octo that has allot of volume and too a good time printing would have been the worse of the group given known PLA heat buildup with large and thick objects. but no problem.

 

I really do not know what to say,  I can't know how technical you are, now "in tune" you are with your printer, what quality your plastic is or is in (I keep mine is plastic bags with desiccant). if your printer is working well and calibrated, what slicer you are using, what FW, what settings. etc  and even if the less general things are shared "settings" "temp" etc they do vary per printer, slicer, and plastic.

So all I can legitimately do is give general advice on the bigger aspects. 

See the problem?  I do not think a few numbers here is the problem. and since the rep2x IS more finicky with PLA you have to have all of these "ducks" in a row or any one of these could cause problems.  The rep2 you could be a bit loosey on a few and it would basic still function if not well.

I say try again,  print with a raft (so that is not a variable), print at .2mm .27mm or more before going down farther. MAKE sure you are extruding the correct amount of plastic!! Keep all of it cool!.

 

Now, interestingly enough . .  I noticed that the prints I did use repg with (I moved on to Simplify3D creator) I did NOT use the PLA setting in the profile. (Repgv40 sailfish) as when ever I did I got strange behavior.  so I modified a ABS profile I was using (changed packing etc) and it worked much better.  . . a potential difference? ??

 

 

 

 

[TaErog]

Sure send a Email and I will fire them over.

[Eric Weber]

Thanks

On Jun 17, 2013 3:58 AM, "TaErog" <tae...@gmail.com> wrote:

Sure send a Email and I will fire them over.

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[FDP]

Just an update, I picked up a Replicator 2 and the PLA experience is night and day with the 2X. I haven't printed anything that challenging yet, but the prints just work. The 2X worked fine for ABS, which is clearly what it was designed for, but I'd say that any other users looking to print a lot of PLA should just go straight for the Rep.2. 

My intention had been to start using the 2X for PLA, and then eventually move to using it for ABS as needed/as I gained more experience. In hindsight I don't think that is at all a good approach with that machine. Just print ABS on the 2X, unless you have a lot of experience and another printer handy to help with making things like fan blowers!

-FDP 

[3DwannaB]

Damian gto knows how to make it work perfect!

The position of the nozzle mate with the tube, the heat signature of the entire assembly, the cooling on to the assembly, the insulation, the extruder feeder design, all work together for it to work or not. Only a couple of people here have stated that they can print both ABS and PLA reliably on a 2x. The majority of those who post here have had trouble with PLA on the 2x.

Want to print both? Want dual extruders? Try the Flashforge. It works.

[Bottleworks]

Just shooting from the hip (Take cover!)....  Because they removed the threads on the 2X, what about putting some thermal compound/grease between the barrier tube and the block?  It might help regain that lost heat transfer. 

On Tuesday, June 11, 2013 12:19:23 PM UTC-4, Jetguy wrote:

Carl,

No, your carriage won't "fix" the thermal issue at all and here is
why.

The 2X is different from previous extruders in that the thermal
barrier tube is no longer threaded into the mounting block. Threads
have more surface area for conduct heat away from the tube and into
the block to be disipated. The real kicker about the 2X is they
machined away a lot of metal away from the thermal barrier tube
mounting hole to make the clamp system. This alone could account for
the problem. The heat is never transfered from the thermal barrier
tube to anythign but the filament. There is not heat in the mounting
bar to disipate to the aluminum carriage.

Therefore, if you wanted to help witht he problem, simply make 2X
mounting bars tapped M6 instead of smooth bore and use bone stock
threaded Replicator 2 thermal barrier tubes. Problem solved.

On Jun 11, 11:58 am, Carl <cpraf...@gmail.com> wrote:
> No offence intended! :-) There must be a solution that is verifiable and
> repeatable!
>
> I wonder if my AluCarriage Dual would assist with dissipating the heat...
> When printing Nylon at around 260 deg C on my Rep 2 - the aluminium cooling
> block is cool to the touch... The is due to the heat sink properties of the
> AluCarriage...
>
> Has anyone who bought one of the initial dual units from me tried to print
> PLA?
>
> If it does not help... the only other solution I can think of is a redesign
> of the thermal barrier to match the MK8/Rep 2... I think the current design
> does not allow a smooth thermal flow into the aluminium cooling block...

[Eric Weber]

Tested the thermal grease idea but not much improvement unfortunately (stinks like hell though).  :-(

--

[Bottleworks]

Bummer.  Someone needs to start playing around with:
http://www.mcmaster.com/#ceramic-hollow-rods/=ncujx9

[Jetguy]

"unfortunately (stinks like hell though). "

That should be a giant clue that what I have said is true. The smell if from the compound being heated and the actual grease portion boiling off. That indicates the barrel is that hot, because it's not being cooled because the small contact patch and even worse, the reduced section of the clamps is providing thermal resistance than therefore NOT conducting the heat away.

 

Think of it this way, the heat is going to conduct upwards from the heater block. The only way to reduce that is to reduce cross section of the thermal barrier tube above the block(AKA make the walls super thin). That in turn could have people breaking the tube if you hit the nozzle against anything accidently. So, the thermal barrier tube is thicker, but then that means you MUST conduct the heat to somewhere and dissipate it. The current clamp system and aluminum block have so much material cut away, and uses a smooth bore instead of threads there is very little one can do.

Others have suggested thermal epoxy but I highly doubt any of that will work and the temps we are dealing with may make it fail. This is not to mention the mess creates as one day, you might have to move or adjust a heater block and nozzle and with epoxy or the other methods you just screwed yourself for removing the head.

 

But hey, what do I know about thermal design?

It's not like I build and modify my own extruders or anything.

On Wednesday, June 26, 2013 1:51:16 AM UTC-4, Eric Weber wrote:

[Jetguy]

On Wednesday, June 26, 2013 3:06:28 AM UTC-4, Bottleworks wrote:

Bummer.  Someone needs to start playing around with:
http://www.mcmaster.com/#ceramic-hollow-rods/=ncujx9

 

While MBuser was suggesting this (holy exotic material Batman), how are you going to make threads in it to attach and seal in the heater block to nozzle interface??

"Machine: Use diamond grinding wheel"

 

Or, just a thought, say you treat this somewhat like the PTFE insert in the MK6. You need 4 stainless screws in the thermal block in tension to a stainless plate and then this thermal tube is clamped to between the mounting and heat spreader plate and the thermal block. But at that point, we are back at stainless steel parts anyway, active cooling and a heck of an expensive hot end.

 

Or, just use a design proven to work say like the previous and cheap MK7 thermal barrier??????????

 

[Jetguy]

If you really want to try ceramic and have some sort of bolt in replacement, request a quote from this place.

http://mangalamceramics.en.ec21.com/offer_detail/Sell_Ceramic_threaded_tubes_for--17620573.html?gubun=S

 

Minimum order 1k units.

 

I'm just saying that ceramic required diamond grinding tools to cut. OK, you can get those even for a Dremel tool. So you buy that tube from McMaster, and then go about cutting them, but isn't ceramic dust a huge health hazard? I mean if there are threads about folks worried about lead leaching out of a brass nozzle (Come on, really? Did you already eat lead paint chips as a kid?), then certainly cutting ceramic at home deserves the same fear and precautions if not worse?

 

What I am presenting is not that you cannot do something, but when do we call the line on practicality?

 

 

Yes, ceramic would be cool. It's been brought up a number of times. That said, the same folks haven't solved or even thought about the problems in a hot end system.

You must seal the nozzle to the thermal barrier tube inside the heater block (heck, we have folks who fail to do this right now and that just an assembly problem). You must then somehow ensure the tube supports the hot end in tension and compression, along with side loads. You still have to heat sink the top side to the mounting bar as some heat is conducted. Yes, reduced but still present. The heat must go somewhere and into the feed plastic is NOT where we want it going. We still then need to make an entrance cone to guide the filament in easily into the tube. The tube needs to be a specific diameter as too large of an ID allows the filament to snake or expand and bind against the walls. Too small and variations in filament diameter wedge it. You need to be able to adjust nozzle height some how with the mounting system. Sorry, a set screw or the current clamp system would surely crush that tube? Maybe not, who knows?

 

 But the real problem in this DIY attempt is how to attach the heater block and nozzle to the tube and have it seal, and have it survive the tension the filament pushing into the hot end pushing the heater block off the tube. So it's both a sealing and an attachment method. Not to mention, machining the tube sounds like a fun operation.

[Jake]

See this guy: http://3dobjectifying.blogspot.nl/2012/12/ceramic-hotend-part-1.html

Claims he has a guy in China that did a minimum order of 10:

I've found a few Chinese ceramic manufactures. Only draw back I had to order 10 pieces for the first batch.. on something that has never been tested, well I'd give it a shot.... and ordered the parts.

He doesn't say where though.  Someone did ask in the comments but he never answered.

[Jetguy]

Sorry, I know I helped pull this thread off topic.

We really need to move a new thread and discuss hot end designs in another thread rather than this one.

 

I say that because I think the author wanted a simple solution to the question of why he and others were having trouble with PLA on a 2X and was there something simple that could be done. I thikn the idea that a setting or maybe something added like thermal paste is the answer we all would like to see it be. Sorry if I'm negative but folks are trying those things and it's STILL not working.

 

I'm only attempting to educate on why I think that is the case and why those simple methods are not working.

 

I'm also not going to say all folks have the problem, there are few who swear they have no issues at all. The problem is, that answer of  "it works fine for me, I don't know why you are complaining" doesn't help the person with the problem.

 

Again, short of replacing the bar or adding some serious directed airflow at the space between the heater block and the mounting bar, are the only real methods I see for changing the thermal charateristics. Adding a fan is no joke either, some folks have damaged motherboards in the process. The other part is how to mount and direct enough air to specifically blow just above the heater block and on the bar. Cooling the topside of the bar won't do much.

And I'm sorry, some of the mod designs that just blow air on the pinchwheel or the filament have NO clue about the thermal issue at hand.

 

I believe in good science and part of that would be to take a cheap multimeter from Harbor Frieght and start measuring tempertures of the different parts of the thermal barrier tube. http://www.harborfreight.com/ac-dc-digital-multimeter-37772.html

Measure before and after making each mod:

So measure a stock baseline, heat the extruder to normal temps for 10-15 minutes at the stead printing temps (230C for most right?).

Insert the thermocouple wrapped in a single layer of kapton into the feed tube/thermal barrier of the hot end.

Measure the top side temp, halfway down through the block, the bottom side of the block, and maybe the barrel itself. You could put permanent marker lines on the thermocouple cord as you insert it to determine the depth you are sesing at and write the data values in a table, again with before and after columns for each mod. So one for thermal paste, one for adding epoxy as suggested. One for adding a fan and so on.

That would be the correct way to dispute the data and determine what works and what doesn't.

 

Right now, we are in a lot of voodo science where one person says it works, another tries those settings and it down't work and we have NO IDEA what is different between the two tests. We need science and numbers to back this up.

 

And to that end, I can say I've at least tried this with a Replicator 1 and my thermal barrier tube in the block never exceeds 46C under worst case conditions. Just below the mounting block where the heat is not being conducted away and there is minimal airflow, I see a rapid rise as I move towards the hot end as expected.

[ten13th]

Hi,

I had my Rep2x for six weeks now.  Mostly I print ABS, but sometime I need transparent parts, so I've been experiment on getting some respectable result with PLA.  Attached is pictures of my PLA print of thing:104120, it printed overnight for 7.1hrs.  As you can see there are some blemishes on the vase.  As it was printed overnight I can't explain what caused the blemish midway up the vase.  There are couple veins that curled up at the bottom of the vase as well.  Here is the setup and procedure I used to get this result.

- thing:94979 upgrade for filament feeder
- MakerWare 2.2.0
- 210* extruter temp, 60* platform temp, rest of setting on default LOW res.
- 3M blue tape
- level the build platform after blue tape is on, then lower it by another 1/8 of turn to decrease the back pressure of 1st layer (Win Risner, MBI Support Agent suggested this)
- hairspray the platform
- leave front door wide open, remove the hood if you have one (I've yet to receive mine, but made a temp one from cardboard box...greatly improved my ABS prints)
- Preheat to 210/60 temp on a cold machine
- Once preheat is completed, I quickly ran 3 load and unload cycles to clean out the nozzle
- Print

Good Luck

On Sunday, June 9, 2013 4:47:46 PM UTC-7, CAD Jedi wrote:

Dear fellow 3-D printer enthusiasts,

I've had my maker bot for about a week and have been printing ABS plastic just fine. Unfortunately the smell of ABS plastic is too much for the other inhabitants of my house so I am trying to switch to PLA plastic. So far, no luck whatsoever printing in PLA plastic.

I am printing with the makerbot 1.75 mm true yellow plastic. The plastic loads fine and ran it for five minutes to clear out any ABS which might of been in the nozzle as you can see in the photo.

When I start to print a part, no plastic seems to extrude out.  Then I head back over to the load filament utility, no plastic extrudes out and I believe it should.  So I unload and reload the plastic.  I have attached a photo of what the end of the filaments look like that I pull out of the extruder.  Fat blob on the bottom followed by a skinny diameter.

I have read and read and read.  I've tried changing the temperature, putting down painters tape and wiping it with acetone, heating the build plate, changing the template to adjust the feedrate and filament diameter.  

I just can't get the PLA to extrude out and have tried temps from 220 - 238.  I've read posts where others claim that they could not print PLA with the right extruder, and I am using the right extruder so maybe that is the problem. I might try the left extruder later, but am weary for today after changing so many settings and testing.

I think this is an extruder problem, either caused by a clog or because the filament is stretched and the feed gear is not pushing the plastic through. It's maddening and I am hoping someone else who had this problem with PLA can share their fix.

Thank you all.

[Damian Gto]

Good to see other print PLA with the rep2x to.

Try to add a Fan that blows to the printing. You might need to use a higher temp if you do it, due it will cool the nozzle a bit to.

You can use any normal fan that you use in a computer. Add a battery to it and put it in the front of the bot.

I use double sided tape and put it in the front top panel. That way it do blow cool air on the middle of the build plate.

[3DwannaB]

This illustrates what I see as the typical assumption that all is well with PLA on the 2x... Damian argues all you need is the downward cooling. This thing has a toolpath which maintains a constant stream and minimal retraction. As such it would minimize the issues others have seen with PLA on the 2x which is the result of retractions of the PLA up into the nozzle then quick downward extrusion in a repeating manner. The toolpaths and the slicers' resulting gcode instructions is the largest variable. I would like to see this poster try to print Cell's bowl which significantly tests a printers ability to rapidly repeat retractions with PLA before any conclusions can be applied.

[veet...@gmail.com]

+756 can't print pla on the 2X.

[Bryon Miller]

Have you made large PLA prints?  Or are these all small prints like a calibration cube?  Could it print an organic character model that is 5 inches tall?  The Rep 2 can.  I think the lack of the downward blowing fan to cool the PLA really is an issue.  If it was possible to make an upgrade to include a fan on the extruder to blow on the PLA as it is layed down, maybe it would work just like the Rep 2.

On Monday, June 10, 2013 6:43:52 AM UTC-7, Damian Gto wrote:

That's not true. Me and other print PLA. So it can be done. The big issue is the heat and you must take care of that.

[Bryon Miller]

They made that decision before they even launched the printer, that's why they labeled it as "Experimental" for the enthusiast.  I took that to read "We couldn't get it to work, but you guys love this stuff, maybe you can".  "Experimental" is a dealbreaker for me, that's why I went with the Rep 2.

On Monday, June 10, 2013 9:51:09 AM UTC-7, FDP wrote:

The Replicator 2X cannot reliably print PLA - period. I have spent a great deal of time trying to get this to work, and finally got MBI support (and sales) to admit that they can't get it to reliably print PLA either. The reasons are stated above in the thread, so I won't rehash them. If you want to print tiny objects with PLA you might be able to get the 2X to somewhat work. 

What is unfortunate is that certain MBI support reps claimed that someone in-house was printing PLA "without a problem", on the 2X, which turned out to be incorrect.

Bottom line, MBI has not bothered sending out an e-mail update re: PLA on the 2X, or posting to this forum. They seem content to let the 2X users eat up their time struggling with PLA.

On Monday, June 10, 2013 11:14:37 AM UTC-4, Carl wrote:

It proves that it is heat creep...

The price you pay for easy nozzle height adjustment on the 2X is that you can only print ABS reliably...

[Bryon Miller]

Does anyone have pictures of large prints that were done in PLA on the 2x?

On Monday, June 10, 2013 10:01:28 AM UTC-7, JohnD wrote:

Chris Milnes has repeatedly said he has no problems printing PLA out of his 2x, of course you have Damien GTO as well, and I can absolutely, positively tell you that if you call MBI to order one today, they will *still* tell you you can print PLA on it...

The above said, I can't make it work consistently. 

[Bryon Miller]

I was looking into this software and posted about it here.  I think it is $120 and the slicer is FAAAAASSSSTTT!  I'm on a Rep 2 though and the plastic extrudes ugly.  I get no help on their forums and my eval expired before they could help me.  I probably will not buy it because of the lack of response but how do you like it?  I love the way they set up supports that you can just place on the model with click and drag.

[how]

@ carl & Eighty

Finally my build plate came back from the shop. Did a few print and failed miserably again. Suspect high back pressure so i increase the distance between nozzle and build plate by 3x using the paper. It helps for the first layer but jam subsequently when build went into 20% or so. With the software i changed to 0.25mm resolution and build progress jumped to 40% before failing. 

Oh well, what a bummer, nothing works and i decided to add some canola oil into the nozzle. Well, lots of mixed feelings when the print went so SMOOTH. first print completed perfectly (30 mins), now im doing a 2 hour print with finer resolution and lower temp. Doing good so far. 

seriously, MKI (or should i say stratasys) should update their maintenance manual and include a bottle of canola oil for all owner of rep2. 

Conclusion, PLA + OIL = happy customer.  

[Eighty]

Glad to hear you solved your issue. This is what I was alluding to when I mentioned having too much friction in your filament. I believe the canola oil does nothing inside the extruder - it really just lubricates the entire feed system.

[how]

Agree. i am imagining without the canola oil or lubricant, the melted PLA is sticking to the nozzle walls and becomes very hard for it to flow thru. 

ok, with that out of the picture, its time to fine tune the machine to print small parts with decent finishes. Any tips on that? 

Cheers. 

[Eighty]

Actually, I'm of the opinion that the problem is higher up. Warm PLA gets tacky, and I think the friction issues are occurring in the guide tube. Hence why some users eliminate the problem when they hang overhead spools.

[how]

Hmm, for my case, i dip the end of the filament which is going to the extruder into the oil and feed it straight to the extruder.

guide tube refers to the threaded metal tube or the long plastic tube?

[dmertens6956]

OK everyone, I finally got my 2X to print PLA with both extruders.  First off, I would like to thank everyone for their suggestions.  After two weeks of trying everything I could think of here is what I came up with.

-  Build plate covered with blue painters tape and then sprayed with hair spray
-  Added 5" fan inside of printer - leave top off - leave front door open
-  Changed out stock extruder to spring loaded extruder
-  Set extruder temperature to 220C
-  Add cooking oil to end of plastic

I am using MakerWare Version 2.2.0.46 and its default settings for all three PLA settings - Low, Standard, and High - only changing the extruder temperature to 220C.
I tried printing my own spring loaded extruders but couldn't get them to work so the ones I finally got to work where the ones I ordered from peoples-exchange on ebay.
I added the 5" fan to the left side of the printer mostly to keep the extruders from getting too hot during initial start up - its location doesn't really blow on them while its printing but I leave it running since the setup seems to be working.  The spring loaded extruders also allow for the plastic to be loaded without using the printer load/unload procedure which might be too hot at 230C.
The last thing I did was to dip the ends of the plastic into cooking oil.  This step might be the only step needed since all the other things didn't work reliably but as I said before the setup seems to be working so I have left all the other changes until I have more time to undo them one at a time to see if it was just the oil that did the trick.  I also still need to play around with the 220C temperature to see if I can lower it to reduce the amount of extra material seeping out of the extruder not being used during dual printing.

I have attached pictures of everything I have used to get this to work.  Once again, thanks to everyone that provided help and suggestions to get this to work.

[Maurice | 3dmaker.co.nz]

I print black PLA on my 2X without any problems, it's the banana yellow one that caused me a headache. What worked for me is to lower the extruder temperature to 220 degrees Celsius (normally 230) and to heat the bed at 40 degrees (normally I use 50) Celsius.

Hope this helps,

Maurice
www.3dmaker.co.nz

[S Scherrer]

 

Hi,

 

I have been printing ABS for few months on my 2X now and ordered some PLA as a try out...  I spend the day on this and after reading various posts and forums I kind of tried several things.- I do not have YET the 3M Blue tape nor any upgrade on the machine (outside the spool holder smaller...as my PLA is not from Makerbot :) , so really I'm talking VANILLA out of the box. I use as well makerware 2.2.2.89 . My personal conclusions are :

 

 - With PLA the nozzle can easily get clogged it seems in between prints . You'll know it immediately in the initial startup when it print the horizontal line.,.. nothing extrudes. Unload and reload filament (with a clean cut on filament) and making sure all remaining in nozzle has been removed once and you are good to go for next one.

 - Extruder temperature = like ABS @ 230. My PLA extrudes without issues. Tried to lower like 210 -220 but nothing was coming out and was clogging.

 - Bed HEATED as I am printing without 3M directly on the Kapton. I heat at 110 (like ABS). Surprisingly based on readings was expecting the first layer to be damaged... did not notice so far.

 - Using a White PLA, 1.75mm

 - Using a custom profile. My startZ is 0.1 and I print height in 0.3 right now

 - My bed is well calibrated (or so I think... what is certain is that I print ABS without any issues)

 - I cleaned the bed with ACETONE

 

What is interesting is this, is that contrary to the use of the 3M Blue tape, the bed is heated and settings are like ABS ones... so I may eventually try a mix of the ABS and PLA through dual extrusion. And then ABS and PVA... !!!!

 

Needless to say I wasted many attempts where the first layers would simply NOT stick. A good leveled bed, a cleaned Kapton with ACETONE and the proper heat fixed the

 

Whilst I ordered my blue tape... I'll see how far I can go with this, as I rarely saw anyone referencing that Heated Kapton could work for PLA.I did read once or twice and even on Makerbot it's barely mentioned.

 

Did the octopus print, I did a larger case (10cm) and the 20mm cube test prints. Results are good with some curved warping on the cube in the X and Y by almost 1mm that I need to investigate (probably the lack of fan and PLA remains too hot when building next layers.

 

Just sharing my experience so far. My main issue today is the regular clogging when the PLA cool into the nozzle and then fail to extrude afterward. If the nozzle remain hot, no such issue.

 

Stephane

[James Taylor-short]

Hi There,

I too have the replicator 2 and am having this problem. I can print well using ABS but the PLA either wont extrude during a print or half way through it it stoppes drawing the PLD through. Would you be able to reply with yourPLA setting please?

James

On Monday, 10 June 2013 15:29:16 UTC+1, DHeadrick wrote:

I have a Replicator 2, so I can't really help you with settings.  I can tell you that those bits of PLA filament that you have pulled out of your extruder look very typical.  My printer works fine with PLA and when I unload the filament, it looks like that at the end.  Just thought you should know that it isn't abnormal looking.

[DHeadrick]

I use PLA from MatterHacker (Natural and Black) just in case that makes any difference.  The Replicator 2 is using sailfish firmware 7.5.  I only slice models created in SolidWorks using Makerware (always the latest version - I don't know which version I was on when I commented).  I don't use any modified profile settings.  I print on the high resolution setting (sometimes Standard if the part is just a rough test and I need it fast).  My shells usually vary from 3-5 with infill between 20% - 50%.  Temperature, I leave at 230C and speeds are at 90mm/s & 150mm/s for extruding/traveling.

The only upgrades I have installed in the bot are my 3in1 extruder upgrade (for reliable extrusion) and a glass build platform (for a flat, non-warping platform).  I damaged my Lexan build surface and have been printing on blue tape for about a week now.

[Joel Edelstein]

If you are having problems with PLA on the Rep2 I would contact MakerBot. The 2, unlike the 2X should print PLA very well out of the box.

--

[DHeadrick]

For about a week... then the stock plunger wears down and you have issues with the extruder.  Unless the new ones have the new spring loaded feeder, which is an improvement but not perfectly reliable.

On Tuesday, 6 August 2013 12:56:49 UTC-4, FDP wrote:

The 2 should print PLA very well out of the box.

[Joel Edelstein]

Ah, yes, I was lucky enough to get the new model. There are still definitely issues* with the machine, but it had worked well for several weeks with PLA under pretty intense use (several 8 hour builds and almost a kg of material so far).

*Whatever you do don't try to change the filament immediately after printing ends, will cause thrashing of the print head.

--

[DHeadrick]

Can you explain this more?  What does "thrashing of the print head" mean?

[Joel Edelstein]

No problem. I had the same problem with the 2X. It appears that there is no global soft limiter on the replicators.
If you try to unload filament immediately after a print has finished (I like to unload at the end of the days printing) a bug in the print head positioning will try to move the head beyond the axis limits in both the X and Y axis. Without any limits (soft or hard) to protect against this, the head will repeatedly slam against the left front corner of the machine.

I covered it in depth in another thread, as it seems like it could damage people's machines I'm hoping MBI eventually fixes it (they have been notified).

[DHeadrick]

Ah... I have never seen this because I've used Sailfish from 7.2 onward.

[Joel Edelstein]

:) yeah, I need to switch to sailfish!