Simple Metal randomy shuts off during print

[ScarabCoder]

Hello,

A few months ago, I had to replace the Printrboard on my Simple Metal (bought the printer nearly 3 years ago now) a few months ago. I ended up only doing a few test and calibration prints, then dropped it for awhile. I took it out again today, and with a bit of calibration it works smoothly.

However, I noticed that after about 40 minutes of printing, it'll disconnect. Looking closely at when this happens, I notice the printer itself switches off then on extremely fast. I thought it might be an issue with the extruder short circuiting or something (someone else had that problem before). I took it out, cleaned it, took it apart, put it back, and the problem is still occurring.

I have the Printrboard Rev F6.
Anyone have any suggestions?

Thanks!

[IB3D]

Try another power supply...

[ScarabCoder]

I forgot to mention, I use a simple laptop power supply (my ATX broke down and I had to revert back). I've tried a different cable already, with a different voltage - nothing.

[IB3D]

Are you using a heated bed with the Laptop power supply?

[ScarabCoder]

No, I'm not.
I'm pretty sure it's overheating, when I touch the stepper motors it's almost too hot to touch.

[RetireeJay]

You can turn down the power to the stepper motors. They should be warm, but not too hot to touch. On Rev F boards, the power is controlled with software commands (documented in this forum and also presumably on Printrbot.com). Each motor has its own power level.

However, this is not particularly likely to be the cause of your shutdowns.

[ScarabCoder]

Thanks Jay, I do remember seeing that somewhere. They talk about the code to put in, but don't really explain it very well. Would you mind explaining how that works to me? I'd really appreciate it.

[RetireeJay]

The following applies to Printrboard Rev F running Printrbot's version of Marlin firmware only, not Printrboards below Rev F and not to the Rev G. But it is valid for any of the numbered sequence within Rev F (1 - 6).

Power to the Stepper motors is controlled by what Printrbot calls "digipots" which replace the physical potentiometers in the lower rev boards. Each "digipot" chip has its own tiny Electrically Erasable Programmable Read Only Memory (EEPROM) - separate from and entirely independent from the "regular" EEPROM on the Atmel CPU chip.

There are three commands to manipulate the digipot chips: M907, M909, and M910.
M909 reads the Digipot memories, as in this example from a Repetier log:

Code: Select all

08:21:24.615 : N15 M909*23
08:21:24.621 : echo:Stepper current values in % (Amps):
08:21:24.621 : echo: X:60.00 (16581.82) Y:65.00 (36581.82) Z:60.00 (16581.82) E:55.00 (71054.55)


M907 sets Digipot "Active Value" - the value that will be used temporarily until power is lost or another M907 command is issued

Code: Select all

M907 X60.0


M910 commits the "Active Values" for all the steppers to their local chip EEPROM memories. This means the value previously set by M907 will persist even after a power-down.

Code: Select all

M910


In Printrbot's implementation of these codes, you use percent. So M907 X60.0 sets the X stepper current to 60 percent of full scale.

[ScarabCoder]

Thanks a ton, I'm really hoping this'll solve my problem as I'm not looking forward to paying $80 to replace an almost unused board.

[ScarabCoder]

Hey, it actually works! Lowered it by about 20% on all axis, hasn't skipped any steps or anything weird, and it's working really well. Thanks!