M2 Shipping Firmware

[Joshua Wills]

Attached is a copy of the firmware that is shipped on the RAMBo
electronics for M2. It is Marlin 1.0.0 RC2, with custom features
added by jonnyr to support the digital potentiometers that control
stepper current. Stepper current settings are in configuration.h.

All settings are configured for a good baseline experience operating
an M2. PID and acceleration values are fine for general use, but your
exact setup (ambient temperatures, table stability, etc.) could
benefit from some tweaking. If there are any changes you feel improve
your operating experience significantly, please share.

[Rick Pollack]

I am not a fan of the name of the electronics....preferring to refer to them as M2 electronics.

[David Sharp]

Is there an M2 fork on github?

Dave

[Doug]

I just have some general questions about this firmware.  The Rambo wiki says that the motor current can be set with an M907 command, what would a full valid command look like. I'm assuming something like M907 Z115 would scale the current for the z stepper to 115 out of 255.  Is this correct?  I'd like to lower the current on the z stepper so it runs cooler, once I find a good set point I'll just change and update the firmware.  Also, could someone explain the steps of updating firmware or maybe share a link?

Thanks
Doug   

[Joshua Wills]

Doug - this link has information on the firmware that we ship, and is posted above: http://makergear.wikidot.com/m2-firmware .  It is a previous version, without the current-controlling gcode.  I'm evaluating the tonokip RAMBo fork, and will be releasing an M2 customized version when I've confirmed everything works as expected.  Until then, you can either modify the current in the firmware, as per the instructions linked above, or take the configuration values from above, and use them in the tonokip version.

[Q*bert]

Hey Joshua or Rick - are you sure this is the shipping firmware?

I think the PID_MAX setting may be different in the shipping firmware.  When I use the posted code I get severe temperature overshoot (20+ degrees) upon the initial heating of the extruder.  When I reduce this setting to half (127 vs 255) it behaves much more like it did originally.  I first 

Am I right that at least this has changed?

On Saturday, August 11, 2012 11:34:49 PM UTC-5, Joshua wrote:

[SMT Guy Austin, Texas]

Did this ever get confirmed?

Thanks!
Brad

On Saturday, August 11, 2012 11:34:49 PM UTC-5, Joshua wrote:

[Q*bert]

Joshua claims the above is the shipping firmware, but I'm not convinced as when I use the code I get severe temperature overshoot.

I think others have seen the same issue - see here.

[Ed Nisley]

I think most of the overshoot problem comes from the thermistor bead's tenuous contact with the nozzle: it's held in place by a wrap of Kapton tape and the fiberglass/silicone tube, so the heat transfer isn't very good. The nozzle gets hotter faster than the thermistor and the temperature overshoots while the bead is catching up.

I epoxied the thermistor bead and a thermocouple to the nozzle, then adjusted the thermistor table to make the thermistor temperature match the thermocouple. After that, the nozzle reaches 180 C in one minute, the overshoot amounts to 10 C, and the temperature stabilizes in about two minutes.... with the default 255 PWM setting.

I've been describing that process on my blog:

• Epoxy mounting
  
• Temperature comparison
  
• Thermistor table tweakage

There's more and better data to come, but so far it's working pretty well...

[terry mccafferty]

Is this still the current firmware for a current shipped unit?

 

On Saturday, August 11, 2012 11:34:49 PM UTC-5, Joshua wrote:

[Konstantinos Papadopoulos]

I think it is as I used it a couple of days ago with my M2 that was shipped about a month ago. Just follow the instructions on the wiki (http://makergear.wikidot.com/m2-firmware) for some tweaks that need to be made. Also don't forget to lower your z motor current so to keep it nice and cool (not actually cool but much cooler).