So I built my ToM in two evenings (about 14 hours total) and everything went together as it should and worked right off the bat. I was like "Yay!". Then I printed some of the basic calibration objects and they came out great and I was like "awesome". Then I was trying some raftless objects and the extruder drive died 1/2 way through my 20mm cube and I was like "WTF"?
The motor spun fine on a 7.2v LiPo battery. So I then put a voltmeter
on the motor lines from the extruder controller and it shows 12.2v.
However it does not seem to put out enough amperage to spin the motor.
It will, on occasion, sort of cough and sputter for a few seconds but
then dies again. I was watching the amps during this and the
controller never put out more than .15 amps which was just enough to
make the motor sort of move, but then it would drop to about .05 amps
which wasn't enough to make the motor spin anymore.
I assume this controller should be capable of putting out at least an
amp or so. Following this assumption I would presume I have a bad extruder controller.
Some other random notes.
- The extruder would not run at ANYTHING less than 255. Not even 254.
- The "debug" light on the extruder board now flashes constantly. Maybe I didn't notice it before?
- I think I was fighting the dying extruder the whole time as I kept dropping my feed rate and seeing only marginal improvements in fill density.
- I also swear I could hear the extruder RPM varying pretty much the whole time I had it running.
- Quite a few other people are reporting similar problems.
I am awaiting makerbots support response.
On the whole I am actually pretty pleased with how well everything went together and that it actually worked right away. The quality was on-par, or even perhaps exceeding my expectations. And I have yet to even try .3 or .2 mm layers.
Hopefully this is just "teething" problems which you sort of have to expect when being an early adopter of bleeding edge technology.
Here are some pics and further notes from my experiences so far.
Current state of T-o-M. Diagnosing extruder drive issues.
Progression of 20mm calibration cubes from Left to Right, top and then bottom rows. 1st cube is with default settings, last is where I ended up after slowing the feed rate and adjusting the perimeter and fill width/height variables a smidge.
Pretty happy with this cube! Now just gotta get my raft settings dialed in.
0.5mm wall calibration cube. 1st attempt, notice "sagging".
Exact same settings as the 1st attempt, but this time I try blowing on it when it starts sagging. You can see an immediate and obvious difference. Time to incorporate a small fan to help cool thin-featured objects.
Man it looks good with enough airflow.