MakerBot Industries

im Ryan i got a thing o matic for xmas
i put it together and after 2 test prints the extruder motor stoped working
so i unplug it from the extruder controller and test it with a 12v power source and it worked fine
so i plug it back in to the extruder controller and it works for about 10sec then slows down and then speeds up then quits
i think its a bad extruder controller or software issue but im not sure
can you guys help?

Well here are a few things:
you can try uploading the firmware again,
try a new rs485 (ethernet cable: DO NOT plug it into a router or anything),
try another rs485 port on your mother board,
or if almost none of that works try running to bestbuy or go to newegg.com and order a new power supply (higher wattage/amps) but thats worst case scenario.
BUT if all of that doesn't work your extruder controller maybe shot ='{

That's probably you best bet. I'd also RMA (send it back) the Extruder DC motor, just in case. You never know with these things…

I was having problems with the extruder motor not running within two days of using my cupcake. Sometimes it would work, only to quit while doing the raft, but most times, it would just plain not work at all. It seemed as though the drivers were just not powerful enough because they were outputting the proper signals. Not sure if it's related, but the ATX power supply died on me shortly thereafter (luckily I had a spare).

I was going to return the board or motor, but since it was Christmas weekend and I wanted to get it running, I decided to tinker with it. You may not want to do this, but what ended up solving the problem for me was replacing the motor driver with an LMD18201 (I had one laying around). This required removing the surface mount chip, directing the logic signals to the screw terminals and hand wiring the LMD18021 to power, the motor and the logic signals. Haven't had a problem since.

If you feel up to removing the surface mount driver and wiring up the LMD18201, let me know and I'll send the wiring diagram.

I think the current drivers are just able to drive the motor in the MK5 extruder and need just a little extra capacity to deal with tolerances of the motor and the chip.

I am having the exact same problem. Motor spins fine on a DC power supply. Extruder driver puts out 12.2v but only at about .05 amps.

I wish I knew how to do Peter Nolan's upgrade, but I am a not an electronics guru. I am quite handy with a soldering iron however! Peter, is the LMD18201chip capable of pushing more current than the stock driver chip? Care to post a little tutorial for us?

I am seeing a lot of people with this issue. Seems like Makerbot either got a bad batch of components or under-designed this board.

I had (or have) a similar issue, although for a few days my DC motor was working fine at 225 PWM, at least after warming up. I was getting some nice calibration prints, and was zeroing in the fine tuning it at 225 (or 230) when periodically it would stop extruding and restart during a print, for ~10 seconds at a time or so; after a day or two of that it stopped extruding at all at any value less than 255. So I restarted tuning at 255, which forced me to a faster feed rate than I'd like.

I just added a 10 ohm power resistor, and seem to be able to extrude down to 205 (the lowest I tested). I haven't done a long print yet, but it seems pretty promising. Thanks for the hint, Clothbot.

More thoughts. I had wired in some LED lighting during all this and noticed a distinct flicker and drop in in the light level as the motor coughed and sputtered. I also noticed the same thing when the extruder or ABP heaters turned on. I never had a volt meter on the PS but I assume it's not maintaining a constant voltage.

Upon inspection I discovered the included PS was only rated to 22 amps on the 12v lines. And these power supplies are frequently "dual rail" or "triple rail" which means there may actually be two 11 amp or three 7amp 12v (or some combination) of supplies inside. I had the extruder controller and a stepper controller on one pigtail and the two other stepper controllers on the other. If this is indeed a dual or triple rail PS, I think we could easily be overloading it, especially as indicated by the flickering LED's. I also assume this could kill power components pretty fast if you driving them from an under-volted and unstable PS. In retrospect I should have thrown the voltmeter on the 12v lines to see what they were doing, but hind-sight is always 20-20 :)

So, I upgraded the PS to a Corsair 650w "single rail" PS. I like single-rail PS's much better because you don't have to pay attention to what's getting plugged in where, to keep it load balanced. There is now, no noticeable LED flickering under any combination of loads and I am quite positive that the included PS is marginal at best. If someone is really interested I could pull the bottom off, again (for like the 15th time), and plug in the old PS and see what the actual 12v voltages are under load.

Also during this testing I have discovered my ABP no longer gets up to temp, it can only mange about 95c. Yet another symptom of a dying extruder controller board I suspect.

Wow! I thought I was alone on this problem. The fine folks at Makerbot have been working with me to resolve this same issue with my machine. This week end I have made some additional observations that may help someone come up with a solution. I added a 6 ohm resistor in series with the motor. It continues to fail periodically during a print. I placed an oscilloscope on the motor leads and discovered that with a speed setting of 255 there is no PWM occurring. So I am getting 11.9V steady state to the motor with the resistor in series.

With a speed setting of 254 I get 0 (zero) volts. The oscilloscope shows no activity. As varying the motor speed is part of the calibration of the bot this presents another problem besides the motor stalling and stopping.

In addition looking at the extruder controller board the Direction LED comes on when forward is selected. The speed LED comes on when a speed of 255 is selected. With a speed of 254 the speed LED goes out completely which indicates that the PWM signal is not being snet to the driver chip.

Is there a Skienforge setting for minimum motor speed?

It will be interesting to see what the solution to this is.

Sorry for the delay. I drew up a schematic, but I just realized I can't attach it, so I'll just describe it.

1. You have to remove one of the drivers on the extruder board. If you don't have the proper tools, use chipquik. Be very careful if you're using desoldering braid, because you can lift up the traces pretty easily.

2. Where the driver used to be, connect pin 6 to pin 7 and pin 3 to pin 10. Be sure to not short the pins to adjacent ones. This will connect the logic signals from the micro to the screw terminals for 1A and 1B.

3. Wire up the LMD18201:

• Connect a 10 nF cap between pins 1 and 2.
• Connect pin 2 to the red lead from the motor.
• Connect pin 3 to terminal 1B on the extruder board.
• Connect pin 4 to GND.
• Connect pin 5 to terminal 1A on the extruder board.
• Connect pin 6 to 12V.
• Connect pin 7 to GND
• Connect pin 8 to GND
• Connect pin 10 to the black lead from the motor.
• Connect a 10 nF cap between pins 10 and 11.

For the 12V and GND connections, I wired it directly from the ATX power supply.

The LMD18201 can be mounted to one of the holes on the side of the cupcake. Also, for the 12V / GND / motor connections, you might want to use connectors.

I hope this helps. I have not had a problem since doing this.

-Peter

I should also mention that I have version 2.2 of the extruder board.