Extruder will not heat

[Douglas Meyer]

Hi, everybody

I have a problem which has taken my Replicator 2 completely down. I just posted the following to Makerbot support, but having read several posts on this forum which lead me to believe that I can't really expect comprehensive support, I am also deliberately 'cross posting' to this forum. (I hope that that practice does not get me completely banned from this one). I believe that the following snippet, all of which was sent to Makerbot, fully describes my predicament. Any and all responses are welcome!

snippet
I have been happily printing since I received my Replicator 2 about two months ago. The Lifetime Total reads exactly 100 hours. I had to adjust the plunger http://www.youtube.com/watch?v=QOJN_8AAC9U at about 50 hours and all was well after that.

Recently I tried my largest printable project http://www.youtube.com/watch?v=QOJN_8AAC9U and it failed after printing several layers. I should have checked the 'raft' option. Due to that failure, much filament (PLA) was extruded that didn't stick to the platform. Instead it stuck to the bottom side of the extruder assembly.

After generating new gcode with a raft, I attempted the print again. This time, the accumulated gcode blobs at the base of the extruder assembly caught the already printed material on the first layer (the raft) and dragged it off the platform. I stopped the printing after that.

Assuming that I needed to adjust the plunger once again, I did so, using the same technique illustrated in the video cited previously. (Because the extruder assembly was now quite hot, I was able to quite easily remove the majority of the semi-melted 'blobs' from the bottom. I felt that I had gotten back to normal. But a problem remained, and here it is:

1. My extruder will not heat.
2. When I attempt to print, the LED printout reads
   2a: Extruder: NA, then
   2b: Extruder: 24/230
2x. Then the print process begins (while the extruder temp is still room temp (24C), and the printer makes passes which would normally create a raft. All the while, this is accompanied by a clicking sound of approximately 150 clicks per minute. No filament extrudes...at all. The nozzle remains cool to the touch.

Question: What do I need to do? Shall I back off that last 1/16 of a turn that your video advised me to make? Or is something else wrong? Mainly, why doesn't the extruder heat?
/snippet

[Eighty]

I may be wrong here, but I don't think this should be possible. One of the start gcode commands is to WAIT for the extruder to come to temperature. If your print begins with a reported temp of 24/230, then something is wrong. Did you recently update your firmware or make other changes? I'm thinking something could be corrupted.

[Douglas Meyer]

Thanks for the quick response, guys! I'm really impressed.

Eighty, a comment or two that I should have included in the original post: My guess is that I can pretty much exclude gcode from the equation, because of a simple test that I should have mentioned (in the original post) that I did: I selected 'Preheat', and got an LED reading the same as if I were trying to print, namely: Extruder: NA. Also it does not perceptibly warm to the touch. In fact, it stays downright cool! I will say that the gcode for this project was created using Makerware, though. My usual practice is to use ReplicatorG, but it actually choked at the size of the project--and that was after over eight hours of carving, slicing and dicing. (BTW, where can I find out what those skeinforge terms actually mean?) But to your original question: No, I've changed nothing in the printer for at least a month/50+ printing hours. I did see that v 7.2 is available and downloaded it a week or so ago, but 'never got around to it'. So that procrastination on my part does seem to make diagnosis one step easier.

Wingcommander, I am somewhat doubtful that I did anything to (at least permanently) change anything physically related to electrical connections (although Occam's razor also persuades me to at least begin considering that possibility.) I say this because I was quite patient and careful when removing the fan cover, making the plunger adjustment, reinstalling it, etc.

It seems to me that both the LED indicator and the lack of nozzle heating complement each other...even though that is only a single datapoint pair. Also, since the reading for the Extruder reads 'NA' and then switches to 24/230 (ambient/target) I am leaning toward trusting the temp reported by the thermocouple and then displayed on the LED.

Are there any test leads that one can tap into with, say, a multimeter to see if circuitry has been interrupted?

Franky, I am somewhat awed by the extruder mechanism itself. Although I am reluctant to try to take it apart, I am nevertheless resigned to undertaking the task if it is necessary. (Actually, I'm not too concerned with taking it apart. What I'm really concerned with is putting it back together again. Correctly.) I don't know if there are springs, cams, skinny little wires or sundry other parts in there to surprise me at the last minute, nor have I seen any diagrams, UTube videos or even narratives at how to undertake such a mission. Yet, I've seen some rather matter-of-fact references to printing new parts (presumably of ABS?) and blithe references to its disassembly. And frankly, I am kind of curious, so I might well take it apart in the morning.

On Fri, Mar 15, 2013 at 9:06 PM, Eighty <adun...@gmail.com> wrote:

I may be wrong here, but I don't think this should be possible.  One of the start gcode commands is to WAIT for the extruder to come to temperature.  If your print begins with a reported temp of 24/230, then something is wrong.  Did you recently update your firmware or make other changes?  I'm thinking something could be corrupted.

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[Dan Newman]

On 15 Mar 2013 , at 6:04 PM, Douglas Meyer wrote:

> Hi, everybody
>
> I have a problem which has taken my Replicator 2 completely down. I just
> posted the following to Makerbot support, but having read several posts on
> this forum which lead me to believe that I can't really expect
> comprehensive support, I am also deliberately 'cross posting' to this
> forum. (I hope that that practice does not get me completely banned from
> this one). I believe that the following snippet, all of which was sent to

> Makerbot, fully describes my predicament. *Any and all responses are
> welcome!*
>
> *snippet*

> I have been happily printing since I received my Replicator 2 about two
> months ago. The Lifetime Total reads exactly 100 hours. I had to adjust the
> plunger http://www.youtube.com/watch?v=QOJN_8AAC9U at about 50 hours and
> all was well after that.
>
> Recently I tried my largest printable project
> http://www.youtube.com/watch?v=QOJN_8AAC9U and it failed after printing
> several layers. I should have checked the 'raft' option. Due to that
> failure, much filament (PLA) was extruded that didn't stick to the
> platform. Instead it stuck to the bottom side of the extruder assembly.
>
> After generating new gcode with a raft, I attempted the print again. This
> time, the accumulated gcode blobs at the base of the extruder assembly
> caught the already printed material on the first layer (the raft) and
> dragged it off the platform. I stopped the printing after that.
>
> Assuming that I needed to adjust the plunger once again, I did so, using
> the same technique illustrated in the video cited previously. (Because the
> extruder assembly was now quite hot, I was able to quite easily remove the
> majority of the semi-melted 'blobs' from the bottom. I felt that I had
> gotten back to normal. But a problem remained, and here it is:
>
> 1. My extruder will not heat.
> 2. When I attempt to print, the LED printout reads
> 2a: Extruder: NA, then

The NA is shown when the "monitor" screen sees that the heater has failed,

if(board.getExtruderBoard(0).getExtruderHeater().has_failed()){
lcd.writeFromPgmspace(NA2_MSG);

Now, when the heater was declared "failed", the routine which did that
declaration also made a decision as to whether or not to abort the print.
Since it did not abort the print, the error must have been a "not plugged
in" error. In that case, the routine has some faulty logic which makes
it NOT cancel the print,

if(heatFailMode == HEATER_FAIL_NOT_PLUGGED_IN)
{
// if single tool, one heater is not plugged in on purpose
// do not trigger a heatFail message unless both heaters are unplugged
if(!platform_heater.has_failed() && eeprom::isSingleTool() &&
(!(Extruder_One.getExtruderHeater().has_failed() && Extruder_Two.getExtruderHeater().has_failed())))
return;
// only fire the heater not connected error once. The user should be able to dismiss this one
else if (connectionsErrorTriggered)
return;
else
connectionsErrorTriggered =true;
}

No platform, so platform_heater.has_failed() is false
You only have one extruder so isSingleTool() is true
You don't have Extruder 2 so Extruder_Two.get…has_failed() is false

Net, net, the routine ignores the error and returns. Bad logic.

Now, why does it start printing then? Elsewhere the code asks if the extruder has
reached temp. Well, it has! When it failed, the current temp reading was set to 1024
to indicate an error. (Note how you saw "24/230" -- that was "1024/230" but truncated
to 3 digits and a leading "0" removed!) Now the code to see if it had reached temp
is fooled by the 1024 being > the target temp of 230 and so it says, yup we've reached
emp. So the printing starts.

Bug!

> Question: What do I need to do? Shall I back off that last 1/16 of a turn
> that your video advised me to make? Or is something else wrong? Mainly, why
> doesn't the extruder heat?

Looks like the wiring for the thermocouple isn't screwed down tight? Or it's
wired backwards? Or the thermocouple isn't working.

Dan

[Douglas Meyer]

Brilliant, Dan!

That not only points me toward the real problem, it (more important) eliminates false leads.

I guess that I will indeed have to take apart the extruder. And maybe Makerbot will have to fix their firmware? And that Wingcommander was right when he said that I had bejiggered something whilst poking around inside the extruder. (But I will check the motherboard connection first, as suggested.) And Eighty was on the right track with his code-based solution, too.

If anybody has any pointers on how to handle extruder disassembly and re-assembly, I'd sure appreciate it.

Doug

[Douglas Meyer]

Just a quick question to any and all?

In light of Dan's exposure of the logic 'deficiency', I wonder if the thermocouple could be damaged by overheating? There was a thick layer of PLA goop on the underside of the extruder, and I'm wondering if that layer might have acted as an insulator/concentrator of heat? Chances are that the filament cooler fan was having no effect at all on the nozzle. Or maybe I'm just blowing smoke. Figuratively, of course.

Doug

[Dan Newman]

On 15 Mar 2013 , at 9:54 PM, Douglas Meyer wrote:

> Brilliant, Dan!
>
> That not only points me toward the real problem, it (more important)
> eliminates false leads.
>
> I guess that I will indeed have to take apart the extruder. And maybe
> Makerbot will have to fix their firmware?

I've already fixed it in Sailfish which inherited some of this code from
the MBI firmware. There's actually a real underlying logic problem in
the MBI firmware which then led to that bad logic code I pointed at.
The bad logic code was someone working around the underlying logic problem.
We fixed the underlying logic problem some time back in Sailfish, but
hadn't spotted that bad if statement which is in a different module.
With Sailfish's fix to the underlying logic problem, that entire if
statement is not needed in the first place.

> If anybody has any pointers on how to handle extruder disassembly and
> re-assembly, I'd sure appreciate it.

Supposedly this means that the analog-to-digical converter thinks
that nothing is plugged in and so a full scale reading is being
read for that thermocouple port. So, if you have access to the
electronics bay, I'd make sure that the thermocouple wires are
screwed down. Look carefully with a magnifying glass to make sure
it looks like they are making contact with the terminals. You might
even give them a gentle tug. If they are and the problem persists,
then that suggests that the thermocouple wire is either broken somewhere
or the thermocouple bead is broken (where the two wires meet at the
end inside the extruder). Not too sure if you can see anything at
the extruder end with that new brass thingy the thermocouple terminates
in.

Dan

[Douglas Meyer]

Where in the bloody universe are you, Wingcommander, that you eat weet-bix for breakfast? Last time that happened to me I could barely understand the blokes because they all spoke (the President's) English with indecipherable accents. I needed my Babelfish, for sure.

And I will try to remember to Talk like a Pirate next September.

On Sat, Mar 16, 2013 at 12:05 AM, Wingcommander whpthomas <m...@henri.net> wrote:

And that Wingcommander was right when he said that I had bejiggered something whilst poking around inside the extruder.

I am feeling strangely telepathic today- must those Jedi mind tricks that parrot has been teaching me - or too many midi-chlorians sprinkled on my weet-bix this morning  =) 

[Dan Newman]

On 15 Mar 2013 , at 10:07 PM, Douglas Meyer wrote:

> Just a quick question to any and all?
>
> In light of Dan's exposure of the logic 'deficiency', I wonder if the
> thermocouple could be damaged by overheating?

Type K thermocouples are generally rated up to 1000C. Some up to 1200C.

Dan

[Douglas Meyer]

Well, that certainly isn't the problem, is it? Glad to be able to put that one to rest.

I will tip it over on its back in the morning to see what I can see. I hope to see something outside the extruder head itself, but am not to confident that I will. After all, the failure of the temp sensor is way too coincident with my poking around (however gently) inside the assembly.

Anybody know what are my options if I can't put my finger on the faulty component/connection?

Doug

Dan

[Dan Newman]

> Anybody know what are my options if I can't put my finger on the faulty
> component/connection?

Odds are, it's a broken wire. You'd then call MBI support and ask for
a replacement. If you have to pay yourself, the good news is that
they are under $20 but then there's shipping.

Dan

[Douglas Meyer]

Also, Dan, what is Sailfish? I've seen 'official' Makerbot references to it, but then I believe that I have also seen a statement or two saying that it's only for older versions of the product line. Like, maybe, ThingOMatic? Or something else? I am confused.

Doug

[Douglas Meyer]

That is comforting. At this point, and for that money, time is more important than money.

But then there is the problem of not having the first idea of how to begin disassembly of the extruder and how to reassemble it. Any recommendations on that?

Doug

Dan

[Dan Newman]

On 15 Mar 2013 , at 10:22 PM, Douglas Meyer wrote:

> Also, Dan, what is Sailfish? I've seen 'official' Makerbot references to
> it, but then I believe that I have also seen a statement or two saying that
> it's only for older versions of the product line. Like, maybe, ThingOMatic?
> Or something else? I am confused.

Sailfish is an alternate firmware for Makerbots which runs on Cupcakes,
Thing-o-Matics, Replicator 1's (dual & single), Replicator 2's, and
Replicator 2X's (considered experimental as neither Jetty nor myself
have a Rep 2X).

Indeed, MBI's 7.0 firmware adopted portions of Sailfish -- namely the
acceleration engine and planner. Sailfish was originally based upon Marlin.

There's some info at http://makerbot.com/Sailfish

Release notes on recent releases at

http://jettyfirmware.yolasite.com/v71-v42.php
http://jettyfirmware.yolasite.com/v73-v43.php

Lots of features above and beyond MBI's firmware.

Dan

[Dan Newman]

On 15 Mar 2013 , at 10:24 PM, Douglas Meyer wrote:

> That is comforting. At this point, and for that money, time is more
> important than money.
>
> But then there is the problem of not having the first idea of how to begin
> disassembly of the extruder and how to reassemble it. Any recommendations
> on that?

I'll let someone else answer. I've actually not disassembled my Rep 2's
extruder yet (other than to put the extruder mod on which I did on day 2
back in very early November). I've disassembled all the other extruders
many times (and built them as well). But this really should be answered
by someone who has been there/done that.

Dan

[Douglas Meyer]

Well, I have a Replicator 2 running MBI's 7.0 firmware. I have downloaded, but not installed 7.2. Should I be looking instead at Sailfish? Are you (and Jetty) under contract to MBI to maintain/upgrade/support it? I will check out the feature list in the morning.

Dan

[Douglas Meyer]

Cool beans.

Dan

[Douglas Meyer]

Oh, what is this extruder mod (that I had never heard of before three minutes ago)?

[Darrell jan]

http://www.thingiverse.com/thing:42250

Discussed in many places, including 

https://groups.google.com/forum/?hl=en&fromgroups=#!searchin/makerbot/wingcommander$20extruder/makerbot/FkuFyY2AXQM/y3-0-s20Sg8J

[Dan Newman]

On 15 Mar 2013 , at 10:32 PM, Douglas Meyer wrote:

> Well, I have a Replicator 2 running MBI's 7.0 firmware. I have downloaded,
> but not installed 7.2. Should I be looking instead at Sailfish?

That's your call. I myself don't run around advocating which firmware people
should run.

> Are you
> (and Jetty) under contract to MBI to maintain/upgrade/support it?

No. It's community generated, tested, maintained, supported firmware.
There's also a mailing list for it, jettyfirmware, over at groups.google.com.
Mind you, MBI did provide us with Rep 1's with which to port the firmware
to the Replicator. Later Bre gave Jetty and myself Rep 2s as very nice
gifts.

Dan

[Douglas Meyer]

Nice

Dan

[Douglas Meyer]

No worries, right? Reminds me of a pleasant week or two spent at a village named 'Cairns', pronounced, oddly, without an 'r' or 's' and hardly any 'n'. Somewhat confusing. The village had a number of things to recommend it, chief among them was access to GBR live-aboards! Spent several days 'upside down', i.e. under water instead of above it. Very pleasant. Good on ya, myte.

On Sat, Mar 16, 2013 at 1:38 AM, Wingcommander whpthomas <m...@henri.net> wrote:

Where in the bloody universe are you, Wingcommander, that you eat weet-bix for breakfast? Last time that happened to me I could barely understand the blokes because they all spoke (the President's) English with indecipherable accents. I needed my Babelfish, for sure.

Central Queensland in that strange upside down land of Oz

[Eighty]

Douglas,
Dan is too modest. Yes, you should absolutely consider upgrading from MBI software/firmware to Sailfish. It will transform your printer into a new machine! But you should master the basics first. Once you're comfortable with setting up profiles, tweaking slicing settings, and figuring out how they all tie together, then you'll be ready for the leap. RepG knowledge is a must (with Skeinforge, usually).
You will be amazed. But it isn't for pansies.

[Darrell jan]

And Wingcommander is the moving force behind the Rep2 extruder upgrade. But he's had no problem recommending it in the past! Seriously, something you should definitely do.

[Douglas Meyer]

I had suspected as much, and was waiting to see it in confirmed form somewhere. Well, here it is. I am going to 1) figure out and fix my thermocouple (?) problem. 2) download and install Sailfish and 3) print and install the extruder upgrade. (Looking at the disassembled parts shows me how well designed for the job it really is. Form follows function, they say. And they are usually right.)

But first, to 1) Without it, I can't even remove filament right now! Also, living in a somewhat unbenighted part of the US, I hope/expect to be able to obtain the necessary metric-denominated parts. If not, I imagine that that I will have to jump thru hoops ordering them from Europe. I will cross that pond when I come to it.

I am resolved to bite the Sailfish bullet. I have acquired some of the art, the lore and the 'feel' of PLA printing so far, but am far from being adept. It seems to me that if I need to learn a set of tools it might as well be Sailfish. I looked at the feature set and liked what I saw. (I looked at Emmet's Automatic Transmission the other day in which he described a simple technique for making two-color/two-ply prints and it did occur to me that one would probably want to jog the gantry off the vertical of the (semi-)printed object but could not quite figure how one might do it. With Sailfish and the Extruder mod, that ought to be a no-brainer.

But now it appears that there are two versions of the extruder mod: Wingcommander's and MBI's. Went to the link given below for thing 53125 (where two makers I respect --wingcommander and emmet-- are credited, plus another guy I have yet to run accross), I presume that's the latest refinement, gentlemen? And glory of glories: they offer a hardware install pack for USD8.00!

I probably better just buy the thermocouple replacement and twiddle my thumbs while waiting for the postman.

Thanks, everyone. It's all beginning to come into focus. This last dozen or so hours on line have been very productive for me. Your experience and lore have been impressive and essential.

Feel free to mine my questions on this thread for more answers, but the key questions have, I feel, been answered.

Doug

On Sat, Mar 16, 2013 at 11:27 AM, Wingcommander whpthomas <m...@henri.net> wrote:

And Wingcommander is the moving force behind the Rep2 extruder upgrade. But he's had no problem recommending it in the past! Seriously, something you should definitely do.

 

That was when I didn't think MBI was taking notice us - I was shamelessly plugging my extruder upgrade whenever I got the chance. Then it hit the top 10 most popular things on Thingiverse for a whole month, and MBI released their version http://www.thingiverse.com/thing:53125 of it, and I felt that we had collectively made the point that extruder problems on the Replicator 2 were not isolated and that this group was not some marginal fringe of wingers that could be just fobbed off and ignored - you can see why John gave me the Wingcommander monkier =) 

I spent the dosh on my Replicator 2 expecting it would be a great printer - it had the potential to be a great printer and with the help of this group its now delivering in spades. The evidence - 100+ hours of print time each week and the bin next to the printer is now only filled with ooze strings, and tare off ear rafts, no failed prints - and the surface finish is as good as it has ever been - thanks to Dan and Jetty.

So I guess I am starting to mellow a bit...

[Eighty]

Doug,
Are you in the continental US? I can send you the bearing/spring/screw for the whpthomas upgrade. Don't bother spending $25 or more for boxes of all the parts. I did, now I have several extras of everything. Just shoot me an email off list.
Now, having said that, there are some limitations of the PLA-based upgrade. Specifically, it bends over time and use. You'll have to print a replacement every few weeks-months. Or, consider ordering an aluminum one (coming soon), or find someone to print you an ABS version. A very generous member on this forum (you know who you are!) printed me an ABS copy, which I just received (haven't yet installed).

[Douglas Meyer]

That's very generous of you, Eighty. I always liked the idea of karma, even though I never truly believed it!

You've put your finger on the one potential problem that I could see with printing a PLA part for use that close to the nasty bits: melting. I thought that perhaps ABS might be more resistant to heat stress than PLA, but having had no experience with it, I was unable to credit my assumptions. You are right about aluminum, I think. It seems like the right material for the job. Now to find somebody who can print aluminum....

Yes, I will be happy to accept your kind offer. And I'll make it worth your while, if not in cash, then in kind. You might want to start thinking about your favorite filament supplier, color(s), etc.

Doug

[Douglas Meyer]

While I am trying to get extruder problems diagnosed, I have an old (~50 hours ago, MakerBot time) story that has never come up until now. I wondered it it might be germaine to my sundry complaints <grin> in this thread:

Some time around 50 hours ago (I now have about 100 hours on the MB), I noticed some flakes falling off the extruder head and into the printed objects. They were tiny, pinhead-sized. Then I noticed a 'flap' protruding from the bottom and it was actually rubbing the newly printed surface on the next pass. Thinking that this must be simply some kind of stupid packing material that I, in my haste, must have neglected to remove when setting up, I tore off the offending material. Then some a little patch of gauze-like material started getting gummed up. So I got rid of that offending bit. And never thought at all about it until now.

But now I'm wondering if the offending bits I removed were actually vital insulation poorly affixed in the first place. The underside of the extruder is a tough thing to inspect, and quite frankly I forgot about it. Out of sight: out of mind, as they say.

Has the pooch been screwed?

[Douglas Meyer]

Hi, Dan

I've been poking around what I think is the 'electronics bay' for a while this afternoon. I am in an electronics bay, but perhaps there is more than one? The one I am looking at is under the floor of the bot, accessed by removing a steel pan while the bot is lying on its side.

I'm trying to follow your instruction, but have pretty much struck out. If I'm in the right place to begin with, I don't have any schematics to work from and don't have a clue which leads support the thermocouple. The most promising prospect is a red/black pair descending from the extruder head and terminating in their own plug/socket combination. The socket is on the motherboard at its edge between the pair of small LEDs and the large character 'B'. Is this where I should be looking?

I took a couple of pix to illustrate. Apologies for their quality; under some duress.

I am beginning to feel that I'm in beyond my depth. Help, guidance, assistance, all the above are appreciated.

Doug

PS Just had a second look at the attached pix, and the LEDs don't actually glow in the pix. They are the objects at D51 and D52, respectively.

Dan

[Dan Newman]

On 16 Mar 2013 , at 3:13 PM, Douglas Meyer wrote:

> While I am trying to get extruder problems diagnosed, I have an old (~50
> hours ago, MakerBot time) story that has never come up until now. I
> wondered it it might be germaine to my sundry complaints <grin> in this
> thread:
>
> Some time around 50 hours ago (I now have about 100 hours on the MB), I
> noticed some flakes falling off the extruder head and into the printed
> objects. They were tiny, pinhead-sized. Then I noticed a 'flap' protruding
> from the bottom and it was actually rubbing the newly printed surface on
> the next pass.

Possibly the ceramic insulation tape,

http://store.makerbot.com/ceramic-insulation-tape.html

which is wrapped around the heater block and then that wrapped
with Kapton(™) tape,

http://store.makerbot.com/kapton-tape.html

Sounds like the tape came loose.

> Has the pooch been screwed?

No, not really, It's just insulation which helps the heater block retain
heat and keep the heat away from your print. If you had some spare
ceramic tape and Kapton(™) you could restore things.

If you are in the USofA and contact me privately, I can send you some.
My e-mail (which doesn't show up if you are reading this via the google
forum) is dan dot newman at mtbaldy dot us .

Dan

[Dan Newman]

On 16 Mar 2013 , at 3:38 PM, Douglas Meyer wrote:

> Hi, Dan
>
> I've been poking around what I think is the 'electronics bay' for a while this afternoon. I am in an electronics bay, but perhaps there is more than one? The one I am looking at is under the floor of the bot, accessed by removing a steel pan while the bot is lying on its side.

That's it.

> I'm trying to follow your instruction, but have pretty much struck out. If I'm in the right place to begin with, I don't have any schematics to work from and don't have a clue which leads support the thermocouple. The most promising prospect is a red/black pair descending from the extruder head and terminating in their own plug/socket combination. The socket is on the motherboard at its edge between the pair of small LEDs and the large character 'B'. Is this where I should be looking?
>
> I took a couple of pix to illustrate. Apologies for their quality; under some duress.

Type K thermocouple wires are RED and YELLOW (standards to the rescue!). The thermocouple wires are usually
in a brownish sleeve. See the picture at

http://store.makerbot.com/type-k-thermocouple.html

BUT DO NOT ORDER THAT PART! The actual part used in the Rep 2 terminates at the non-yellow/red end
with a specially machined brass part. That part is NOT in the makerbot store and only available
if you call Makerbot on the phone. The support folks, who are REALLY GOOD ONE ON ONE and go above
and beyond when you are working with them can send you one after first working with you
to confirm you need a new one as opposed to just needing to cinch your existing one down.

Dan

P.S. The MBI support folks are truly very good and very dedicated. I cannot say enough good things
about my interactions with them going all the way back to the Cupcake days and when I think Ethan
Hartman WAS the entire support team. It's in the e-mail and electronic communications where I think
they tend initially (triage stage) to be a little too terse and abrupt. ("Keyword in index" is the
term that comes to mind.) But get them on the phone or past the first initial electronic response,
and they will hang in there with you to the bitter end and follow up afterwords.

[Douglas Meyer]

Hi, Dan

Your advice and encouragement this last 24 hours or so have been invaluable. I have finally gotten up the nerve to take apart the extruder head and now have quite a good idea of how it all works, where the key components are located and a much better sense of how they all work together.

I said that the extruder head is taken apart--but that is not entirely true. One component (the metal block that rests in the Y-axis carriage yoke and contains the nozzle, heater and thermocouple) remains. The metal assembly is surrounded by PLA goop that had been extruded during the last (failed) run and then set. The goop pretty much surrounds the metal block and prevents me from removing the block from the Y-axis carriage yoke.

The cold PLA is pretty strong(!) and completely resists gentle hints from the blade of my screwdriver. It also obscures (partially) my view of the thermocouple, although I can now clearly see the leads that you referred to yesterday. The PLA goop has pretty well pinioned the metal block into place in the carriage. I should also say that I have found and removed all the capscrews that fix the metal block to the carriage, and there is some definite play between the two components, so I am fairly sure that the only thing that still keeps the two parts together is the deformed plastic.

A thought occurred to me. If I were to be able to apply power to the heater, I'm fairly sure that in short order the plastic would soften enough for me to grasp the metal block (with an appropriate pliers, of course) and pull it free from the PLA mess.

But since the initial problem I'm trying to solve is a lack of heater response, and the proposed solution involves creating a heater response, I find myself with a dilemma. Then in the shower this morning it occurred to me that perhaps there might be a tweak or diagnostic override somewhere in the firmware (either generic MBI or Sailfish) that allow me to temporarily turn on the heater long enough for it to soften the PLA constraints. Any thoughts on that?

I have a very short, very amateurish movie of the situation that I can include in a follow-on email, if the word picture above is inadequate.

Best

Doug

[Dan Newman]

On 17 Mar 2013 , at 10:07 AM, Douglas Meyer wrote:

> Hi, Dan
>

No magic secret sauce in the firmware. The leaking PLA is not normal, but
folks have reported it occurring. (Something isn't seated as well as it
might be.) And PLA is pretty hard stuff but does soften around 100C. Problem
is that some of the surrounding parts are ABS which might also soften if
you're not careful (e.g., if you used a heat gun).

So I'd seriously wait to talk to MBI support before doing something which
they might construe as violating warranty. As things stand now, they may
well repair things at their own expense. But if you do something they don't
appreciate, they may put the onus on you.

Dan

[Douglas Meyer]

Sounds like good advice.

....one more day without printing. <sad>

[Douglas Meyer]

Thanks, Jetguy, for the comment about heatguns.

I will keep one in my Utility Belt in case I need it.

Seriously, your comment makes a great deal of sense to me, and it does seem to me to be a natural auxilliary tool for anybody who works with melted plastic.

I'll be checking in with MBI by phone, as Dan as recommended, first thing in the morning. I didn't really realize that there were possible warranty issues here (I thought, rather seriously, that this was all experimental, as in amateur radio, homebrew computers and arduino robots, and that we were pretty much cut off once our box of awesome arrived. I guess that it is me who arrived...and several years too late!)

I am pretty hopeful that I can get my immediate problem resolved through future conversation(s) with MBI. I hadn't known the protocol, either. That's not clear in their support promise, I guess. I had lodged the issue on Friday afternoon via the Makerbot website and received an open ticket report from them later on in the evening. I suppose that was a robot telling me that my request for help had been received. I was assuming that I needed to 'go thru channels' and stay in the email channel. But thanks to Dan's advice, I will also double up by phone. I am quite hopeful of an early resolution. (Mark my words!)

Doug

On Sun, Mar 17, 2013 at 7:10 PM, Jetguy <barry...@hotmail.com> wrote:

Also, I don't know why this isn't higher on the list of stuf to try
first. A heatgun does wonders. The entire hotend can be heated
externally with air. It doesn't get mmuch easier than that. A decent
heatgun is also great for fixing warped parts, cleaning nozzles to
keep a few spares around etc. Pretty much the IDEAL way to remove it.

> >https://groups.google.com/d/topic/makerbot/TwjG3qsq3DY/unsubscribe?hl...

[Eighty]

MBI email support took a nosedive somewhere around the first of the year. Like the old moderator, Andrew, (who stepped aside in mid-December) put it, there was most likely an onslaught of Christmas present recipients that needed help. The Rep2 was going like hot cakes, and now the Rep2X is doing the same. They're just under water. But you will find that a phone call is quite the opposite: quick and courteous. At least, it'll get you started. But by then, your issue is being dealt with by a person - not a machine. They'll follow up with emails, and you actually know who you're talking to.

[D3F1ANT]

I've been waiting for 2 weeks for MBI to reply to my support ticket. My replicator 2 seems to have developed the same problem, no heat.

B.

[Douglas Meyer]

D3F1ANT, what were the circumstances leading up to your heat failure? Was there anything noteworthy? How many hours of print time did your printer have?

BTW, my Rep2 was also a Christmas present. To myself. <grin>

--

[Douglas Meyer]

I would say that you should call 'em up. I posted my (fairly extensive) problem statement late Friday afternoon--actually, it was probably after closing time in NYC. I had a number of conversations on these threads over the weekend, finally gaining enough courage to disassemble my extruder head. Then I found some real problems. I called MBI first thing this morning at their support number (347-334-6801). Got thru the wait queue in less than a minute. Talked to a real person, referenced my ticket number, and had a real dialog. Straightforward and to the point. Sent him a couple of pictures and have an interim pathway to follow, at least a set of steps that I can take to get me closer to the final diagnosis. They are some of the best responsive (by phone, at least) customer support people I have ever dealt with. And I have done software development for forty or so years, so I have been on both ends of their phone line. (I do agree with others that their email support sucks. Phone service is first rate.)

So give 'em a call.

On Sun, Mar 17, 2013 at 11:21 PM, D3F1ANT <ba...@dinger.co.nz> wrote:

--

[D3F1ANT]

I bought mine for mostly for work related rapid prototyping buts its easily one of the most productive gadgets I've ever bought.

It was printing away nicely a few minutes before, I loaded up the next print, and went off the make a coffee. When I got back it was still 'preheating'...and well that was all its done since, just says preheating, no errors. The displayed temperature changes with ambient so I don't think its the temp sensor. It just seems weird there no fault detection built in. The Heater measures a few ohms so I'm guessing its not that. I've not been been able to find out what the actually voltage/current is supposed to be but I have a feeling the main board just isn't outputting any power to it. I don't want to get to carried away 'repairing' it myself unless MBI say its ok and won't affect my warranty. My guess is the heater output driver is toasted, or has a bad solder joint.

I'm tempted to just order a spare heater (which I think means an extruder cause it seems to be securely held in there) and spare mainboard to allow for a quick debug by exchange ;) I'm in NZ and not so keen on the cost of the phone call so will wait patiently a bit longer.

[Eighty]

Is it just me, or there a LOT of heater errors being mentioned lately.  Are we seeing another common defect?  I guess we need to find the resolutions to all these posts, and see if there's a trend.

 

D3F1ANT, did you say that this is one of the most PRODUCTIVE gadgets you've ever bought?  LOL!  How many other gadgets have you had to stare at for 10 hours, just to get a dinky piece of plastic?  I love my printer - it's changed a lot of things for me.  But making me more PRODUCTIVE?  Hah! :-)

[Douglas Meyer]

<<I'm in NZ and not so keen on the cost of the phone call so will wait patiently a bit longer.>>

I've heard that they have Skype in NZ :-))

Sorry for making light of a pretty hopeless-feeling situation.

I know nothing about electronics, so I can't help you there. But I do know that I 'announced' my problem here just a couple of days ago and got a great deal of knowledgeable support from true experts in this game.

Give that a shot, too, maybe.

Doug

[D3F1ANT]

No it really has increased productivity. I do a lot prototyping, and being able to just print a hard copy of an object that will later get injection molded or machined from solid is awesome and doesn't tie up my time. Nothing beats being able to physically hold an object. I've even started using to for small production runs of parts. 

[Eighty]

Douglas,
Just curious as to the status of your issue. Did you figure out what it was?

[Douglas Meyer]

Thanks for keeping me in the loop, Eighty.

I have let it rest for the last forty-eight hours. I have got the extruder head as disassembled as I can get it using common tools like hex wrenches. I intend to remove the carrier (the plastic that traverses the Y-axis) from the bronze bearings to free it so that i can get a better purchase on the problem. I have made a video https://www.youtube.com/watch?v=8MGP-xvepLU of the problem and it's still in the state shown in the video. (Not sure if I have forwarded the video to you earlier or not.)

I have high hopes that once the carrier bracket is free I will be able to see the problem from all dimensions and I expect to be able to free the 'hot end' (the metal part that holds the nozzle, heater, thermocouple and I don't know what all else) from the plastic carrier by carving away enough of the PLA goop to free it completely. Then I will finally be able to get to the thermocouple and to the heater. I am convince that one or both of them, and/or one or both of their sets of leads is damaged.

I would have probably had this task completed by now had I not had family obligations these last several days.

Doug

On Tue, Mar 19, 2013 at 6:57 PM, Eighty <adun...@gmail.com> wrote:

Douglas,
Just curious as to the status of your issue.  Did you figure out what it was?

[D3F1ANT]

Just watched your little video...crickey that looks messy. Over what sort time did that happen? I guess it was unattended print...note to self, check on my bot regularly.

I once did a quick test print and just had a new spool sitting on the floor, the filament was crossed up and the entire reel ended up lifted well clear of the floor, Wingcommanders extruder upgrade works almost too good :) 

[Douglas Meyer]

Yeah, I'm going to print his extruder mod first chance I get.

Crikey, that *is* messy. I have been picking and chipping away at the PLA off and on all afternoon (it's shortly after 7PM here now). I have gotten it down to (Damn, I haven't got any vocabulary for this job) it's the little square metal thingy that's connected to the other metal thingy by the threaded pipe that ends in the nozzle.

I'll try again. All the essential parts meet in a metal block about 2cm on a side and 1 cm thick. I have managed to get that piece completely isolated from all the other bits without breaking any of them.

That little block contains at least 1) the heater, 2) the thermocouple, 3) the nozzle and 4) an unknown bump that seems to be something running parallel to the nozzle. There is still a fair amount of goop there, but I might be able to hack away everything I need to fairly soon.

I fear that the thermocouple is shot. I actually think that its failure is related to the heater failure. My working hypothesis is that the thermocouple failed first. That caused the motherboard to stop putting out a command to call for heat (or in reality, to supply the necessary current for the heater. That perhaps caused partial heating, at least enough to extrude some goop and all the x-y motion caused it to work itself up into the carriage. I don't know and probably will never know.

I tried to cut thru the PLA with a jeweler's hack saw and it worked, but too slowly. It would have taken hours to free the hot end. I toyed with the idea of applying external 24V to the heater and just let it soften up the goop and then extracting the hot end that way. But I thought that might cause perceived (or actual) damage to the heater and might cause a voiced warranty. Then I realized that my old soldering iron had a spade tip and bingo! I was able to carve my way thru the PLA like a <pardon me> hot knife thru butter</pardon me> It was such an easy metaphor. With the hot knife tool, I can pretty much remove all the PLA goop except the film residue. I think that I'll be able to get things cleaned up pretty well.

MBI promised today to send a replacement thermocouple by postal mail, gratis. I will probably not do much more until I have got that replaced. Probably no sooner than the weekend, at best.

I'm feeling that I'm in much better shape than I was 24 hours ago. And I was in better shape then than the day before. Unfortunately, I have done no diagnostics (because I don't know how to do it, and don't have any ranges, values or target numbers to be shooting for), so all my decisions have been guided by informed intuition. I sure hope that I have been making good guesses.