Makerbot Replicator 2 extruder troubleshooting

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So me and 5 other users of a 3D printer (MB Replicator 2) are experiencing extrusion troubles. This fault began to appear around 199 hour of use mark.

If an object is around 100mm wide or around that size (everyone is printing snowflakes) and settings in general are layer thickness at 0.15mm at 230C (temperature has been changed at times to 240 and 210), printer makes a thin bottom layer of an object, but after completing part of another bottom layer, it stops the extrusion completely, what's more, extruded strings are not even along their length. When extrusion stops, either the filment is stuck and difficult to take out or filment is taken out and loaded back in and again everything is almost ok for those first layers. We also did motor clean up by the manual. Issue got worst with every try until I decided to take it apart entirely.

Our troubleshooting:
We made couple of cleanings and reloads of the filment as well as different settings, but the issue persisted, so we concluded that the issue could be at the metal heat tube which can't exactly be easily accessed. I took apart the extruder, only to discover that the heat element is still pretty much inaccessible. Heated up needle, tried to get it through the hole, but needle was too thick. So heated up the heat element up to 280C and pushed filment manually - it wouldn't go in until a burning smell, smoke and a black drip came out from the other end (extrusion end) then the filment pushed through - I pushed through a fair amount of filment to make sure whatever is built up and burned there gets pushed out entirely. After that we put the whole thing back together. Another user calibrated and tried making her object, but it repeated the issue, however, when I recalibrated it, picked a "Nut and Bolt.x3g", it came out succesfully. Now another user is trying his snowflake and right now it looks like it's going fine. I am not sure if the issue is fixed yet. Oh and I lubricated axis.

History of issues:
On the occaision we got the regular filment stuck when changing colors, but following manual we solved it easily by taking out motor and cleaning it out. Most issues we had were with white color - I'm not sure what's up with it, but it keeps acting like an arse.

Your assistance:
We are not in a situation where we can go to a local hardware store or call a help desk (read my other topic), the only option is, is to give the MB to the people who gave it to us to solve it, however, I believe this is an issue a user can deal with on his own. I'm sure someone here has a greater experience troubleshooting 3D printers, so if you could please help me understand what's causing this, how to avoid this and how to more easily solve this, I would really appreciate it - I ilke 3D printing, so I don't want to give it away for couple of days.



It looks like the team (rest of the users) want to give it away for someone else to clean/fix it - not much problem there, we can't get other chemicals freely anyway. I'd give it a couple of more tries, but team is really bent on giving it away.

Oh well, thanks for the advice, it will come in handy in future. If there is anything else I should know, then go on ahead and share it, I'm learning.

Had the same experience, changed the nozzle as the stock is plain brass. Fixed the issue.
Recommend a Nickle XT if you ever get another:

I've been experiencing a similar problem.
My Thermistor needed replacement, the hot end would become way to hot as the thermistor kept on giving too low values. This caused heat creep flooding the entire hot end with PLA to a point where the PLA would just cool down and clog the nozzle,

My best guess for your situation would be to replace the Thermistor or print at significantly lower temperatures (20C less or so)

I have been having a intermittent problem with prints. For a time the machine prints perfectly and then I start having difficulties with the extruder skipping. It is difficult to describe. I have taken photos of a part exhibiting this problem, but I don't know if there is a way to post photos of it. The print begins well, then skips for a bit then begins to build normally and then skips again and ended up printing normally! This happened a few months ago and I had not used the machine at all. Then recently I was able to burn a couple of parts without incident and now today the problem is back. I am running with the settings on default. I thought it might be the filament, so I tried a different reel and nothing changed.

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You want to give it away? Heck, I'll take it!

Not like that - give it away to fix it and later return it.

I have idea this morning. I was having very similar issues, but they reduced / disappeared (fully after cleaning) after I started printing with lower speed and lower feed rate. At high feed rate liquid material was building up in the hot end much faster then he was able to be removed via the nozzle and was coming out under pressure backwards, clogging the input. Try to reduce speed and feed rate by 20%.

I'll take note of that, but team has already decided to give it away.

Thanks for all the help.

Do they know who they are giving it to?

People that gave it to us. It's a small 3D printing company in Baltics.

Thirdly, your white filament that's causing most problems just may be of a poor quality. Nothing much can be done against polluted filaments but throwing them away and using better stuff ;)

Canola oil tip sounds like a thing that could do the trick, however I can't get anything like that - getting aything here is pretty difficult, but I'll keep it in mind just in case an oppurtunity rises.

Plier tip seems like something I could be able to do, so I'll tryy that if the issue repeats itself.

It's a Makerbot Warm grey filment - it shouldn't be of poor quality, but then again I don't know since I don't have whole lot of experience in this field.

Thanks for the the tips, I'll see what I can do..

Clogging can also sometimes be solved by sticking a piece of filament in the fully heated hot-end, push it in as best as you can, then let it cool down to 80-90 degrees Celsius, and with one short pull with pliers, removing the filament the same direction you pushed it in. Repeat if necessary. If successful, you'll see some debris at the end of the filament. This method sort of requires you to dismantle the machine a bit (I'm not sure how the makerbot works, but with Ultimaker, you need to remove the transparent plastic bowden tube the filament is led through, because you need to apply force directly away from the hot-end).

I've had these problems with my Ultimaker. Following an internet tip, I now dip my filament in canola oil before I insert it into the machine (4-5cm, just coat it, make sure it's not dripping or it'll get messy; I just do it whenever I replace the filament, so not after every print) and that seemed to fix the problem for me. 'The internet' was specific to use canola oil (don't know what's special about it though), but I understand you have limited access to stuff, so if you can't get any, try another cooking oil. As an added bonus, the machine smells nice from time to time. Haven't seen any negative effects on the prints either!

Thanks for the tip, for the future I'll keep it in mind, but we are giving the printer away to those who gave it to us.

What is material of your extrusion head? I never had makerbot, so I ask, printer that I have, has brass extruder head, I'm cleaning it with different set of chemicals designed for cleaning carburettors and vibration bath I'm using CarbMedic and Wurt... and acetone if I used ABS. oh, and I repeat this process couple times, every time cleaning it with compressed air. I'm doing this + - once a 6 to 8 month. Whole process takes me 90 min max

If it's not temp sensor like Corona688 wrote.

To be fair, I don't really know - it's not written in the user manual and the only internet page I have available is this.

Not that I have access to those things, but I'll take a note of the tip - if I have any chance of getting additional cleaning chemicals, I need to understand what chemicals I need.

You need something that can react with the printing material and not corrode the nozzle / hot end. By the temperature you describe I assume you have ABS, acetone would work fine if you can safely unscrew the nozzle and put it in the acetone as long as it needs to remove build up ABS. I understand that you must be very careful and you don't have big amount of spare parts.

I wrote in other post that you can reduce print speed by 20% (feed rate is normally reducing wit it, but if not reduce it by the same amount) it should reduce pressure inside chamber with molten plastic in the hotend. Oh and if I'm wrong and you are not using ABS but PLA, reduce temperature, I advice to not exceed 220C if you are using PLA I'm printing PLA at 217C

Edit. I looked at the spec of makerbot, it looks like standard brass nozzle if you need you can unscrew it and clean it.

We are using PLA. Does acetone react with PLA plastic? I have no way of researching this now, so sorry for the simple questions.
I'll take note about temperature for the future, but it looks like the team (rest of the users) want to give it away for someone else to clean/fix it - not much problem there, we can't get other chemicals freely anyway. I'd give it a couple of more tries, but team is really bent on giving it away.

Oh well, thanks for the advice, it will come in handy in future. If there is anything else I should know, then go on ahead and share it, I'm learning.

No, acetone reacts with ABS only, PLA is very durable polymer, only things I found that can melt it was those carburettor cleaners / industrial solvents.


  • if you wand to unscrew nozzle it must be hot (in other ways plastic inside wont let you do this and you can damage the nozzle)
    -PLA melting point is somewhere between 170 and 190 (it depends on mixture between polymers PLA and PDA and it can depend on dye)

  • you don't need heated bed if you have tesa masking tape, or kapton tape

  • start printing with medium speed settings and go faster with every print, doing that you can find optimal printing speed for you printer

-it's good to have something that cleans filament before if will enter the feeding port of the printer (dust is your enemy), some kind of sponge or something like that

-keep electronics cool

-do not exceed 220/225C with PLA, self combustion point is somewhere near 370C but combustion gases appears near the printing temperature (it depends of mixture PLA and PDA polymers within filament called PLA-D, clean PLA starts decomposing at 200C PDA is more durable, and stabilise mixture but for safety issues do not exceed 225C), so basically you are burning PLA inside printer at higher temperatures

I think most of your problems came from there, no one told you about temperature settings, and optimal temperatures, you were burning filament inside printer clogging the nozzle with burned material.

Ok, thank you,

I believe the fault then was the burning of PLA since combustion gases were present at one point. We are still giving it away for cleaning, since we can't get the necessary cleaners and be confident whether it will self clean with time even at slower speeds.

So when we get it back, we won't exceed 220C.

Thank you again, I appreciate it.

It could be a temperature sensor issue. Inconsistent tempertaure can cause the extruder to jam like this. It can be frustratingly difficult to predict if the trouble is due to fraying wiring. The left head of my X2 showed similar symptoms for some months before it eventually conked out with temperature sensor errors.

If you're lucky, it's a loose connector, you can tighten some wires and it will start behaving again.

I had this with my printer as well. I had to return the machine and get a new temperature sensor. With the new sensor none of this nonsense appeared again. My printer would print 10 mm of height and then stop extruding due to low temp.

Sounds like a drag to fix with what I have, hopefully it's not that or if it is, then hopefully it's just a loose connection. I'll try checking the wiring, thanks for the tip.