MakerBot Motor Issues
In September and October 2010 MakerBot Industries received a number of support requests relating to our 37 mm extruder motors. While we have always been ordering the exact same part number from our supplier, It has come to our attention that we have been receiving two distinctly different motors.
In an effort to determine the cause of these issues and respond accordingly we are asking the community to help us do some science. Please complete this form once for each motor you have purchased from us. This will help us determine the quantity and failure rate for each type of motor. Even if your motor has never given you problems, it is important for you to provide feedback.
After removing the white plastic cover from each type of motor the difference is clear. One has a circuit board while the other does not.
The two types of motors we have in stock look different on the outside. The motor with the circuit board has a dull body with a shiny ring near the plastic while the other motor is completely shiny. This is true for the motors we have in stock, but we don’t know if the motors with shiny rings have always had the circuit board.
For more photos view the Motor Issue photo set.
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9 Comments so far
charlespax
I removed one of the questions because it appeared twice. If you’ve already submitted your form, don’t worry. The information is still there.
Tim
Where is the form?
Adam
Does this apply to orders that haven’t shipped?
charlespax
@Tim The form should be on the blog post above. It is an iframe of a google form.
Sveinn
Man, I completely sympathize with these kinds of issues. I had a supplier rev a part without telling us in order to “improve” it. Turns out that it caused our product (which we had logged tens of thousands of reliable operation) to randomly fail in the field when it got too hot. The only way we could tell the difference between the two revs was to look for a 5 mil strip of black resin using a jewelers loupe. Drove me up the freaking wall.
Jeff Christiana
Will everyone be sending back their bad motors and receiving new ones? I am at a stand still now that both my motors have stopped working. The motor with no pcboard lasted about 2 1/2 weeks. The one with the pcboard stopped working in a week.
Eric
I’ve had the motor with a circuit board for about a day, and recently it has stopped working, so… what is wrong? I Tested the capacitors on the circuit board, and the capacitor used to even out the voltages between ground and +12 v was shorted. So I removed the capacitor and tested it with a power supply and it worked perfectly. I have a feeling that the thermisistor is becoming disabled while the motor continues to work and the machine thinks that the heater is still very hot. When the heater eventually becomes to cool for plastic to melt, the computer thinks it is still hot, therefore the motor to extrude the plastic continues to “try” to turn, and because the heater element has cooled down the plastic is unable to melt, and the motor cannot turn the plastic, so it shorts, and becomes disabled till the machine is reset. I think that it is a software problem, but am not sure. Anyone have any ideas or have had the same problem?
charlespax
That’s strange that the cap was shorted. That would usually cause more serious problems.
There is a bug in replicatorG that is killing prints mid build if the previous build was stopped using the Stop buttpn. This is fixed in ReplicatorG 21, to be released in the next day or two. I believe this will solve many of the problems people have been experiencing. This should solve your problem. The fix is already in git.
It turns out that the motors that have been seizing because the first gear in the gear box is binding with the gear on the motor shaft. This can be fixed by moving the shifting the gear box relative to the motor. I’ve done this by plugging the motor directly into the 12 volts of the power supply, holding the motor in my hand, and wacking the gear box with a hammer.
There will be a blog post with this information and a look at what went into tracking down the bug.
Charles Edward Pax
After extensive research we believe the bug causing mid-print failures
has been found and fixed. The page linked below is just some of the
research done in tracking down and fixing the issues.
http://wiki.makerbot.com/the-great-motor-mystery