Need to switch the hotend and hotbed on Printrboard Rev D

Code hacking talk

Need to switch the hotend and hotbed on Printrboard Rev D

Postby scholzie » 2013-May-Thu-00-May

My printrboard Rev. D came with a bad hot end mosfet. My workaround (until I hopefully get warranty replacement...) is to switch the thermistors around on the board, and move the hotend over to the hotbed circuit.

However, the firmware still addresses the hot end and hotbed separately when sending/interpreting G-code, so that won't get me very far. For instance, if you just swap the cables around and change the limits in Configuration.h, the hotend will heat up. But when Pronterface sends the "shut off hotend" signal once it hits right right temperature, it never actually shuts off, because it's not plugged into that port on the board... So really what I need to do is switch the ports around in the firmware as well. For instance, if port A was hot end, and B was hot bed, I simply need to swap those so the right G-Code commands go to the right headers.

Does anyone know where that stuff is in the firmware, and if this is easy enough to do? It seems like this should be REALLY simple - a matter of switching two values around.

I already updated the max temps and thermistor values to match what's actually been switched around physically.

Thanks!
  • 1

scholzie
Levelling print bed...
 
Posts: 25
Joined: 2013-May-Tue-05-May
Reputation: 1

Need to switch the hotend and hotbed on Printrboard Rev D

Sponsor

Sponsor
 

Re: Need to switch the hotend and hotbed on Printrboard Rev

Postby scholzie » 2013-May-Thu-00-May

I think I found it in pins.h - just switch pins 14 and 15 around. I'm going to keep poking, but I think that's it. Update the ones for the thermistors as well and I don't have to move any physical cables.
  • 0

scholzie
Levelling print bed...
 
Posts: 25
Joined: 2013-May-Tue-05-May
Reputation: 1

Re: Need to switch the hotend and hotbed on Printrboard Rev

Postby scholzie » 2013-May-Thu-01-May

That did the trick, by the way... Just find the second corresponding to motherboard 81 in pins.h, and swap the hotbed and hotend pins. Leave everything else alone in the firmware, and swap the extruder cable into the hotend port. Worked like a charm. Printing the calibration cube now!
  • 0

scholzie
Levelling print bed...
 
Posts: 25
Joined: 2013-May-Tue-05-May
Reputation: 1

Re: Need to switch the hotend and hotbed on Printrboard Rev

Postby scholzie » 2013-May-Thu-01-May

That did the trick, by the way... Just find the section corresponding to motherboard 81 in pins.h, and swap the hotbed and hotend pins. Leave everything else alone in the firmware, and swap the extruder cable into the hotend port. Worked like a charm. Printing the calibration cube now!
  • 0

scholzie
Levelling print bed...
 
Posts: 25
Joined: 2013-May-Tue-05-May
Reputation: 1

Re: Need to switch the hotend and hotbed on Printrboard Rev

Postby AmazingSpanoMan » 2014-Jun-Fri-11-Jun

scholzie wrote:I think I found it in pins.h - just switch pins 14 and 15 around. I'm going to keep poking, but I think that's it. Update the ones for the thermistors as well and I don't have to move any physical cables.



Where did you see pin 14 and 15. the pins.h I have is showing 20 and 21.

I'm trying to reroute the hotbed pin to correspond with the stepper motor fan code that is in the configuration_adv.h
  • 0

AmazingSpanoMan
Waiting for printbed temp...
 
Posts: 122
Joined: 2014-Mar-Thu-21-Mar
Reputation: 6

Re: Need to switch the hotend and hotbed on Printrboard Rev

Postby lwalkera » 2014-Jun-Mon-23-Jun

Also, make sure you don't drive the that FET with PWM. The gate capacitance on the bed/hotend FETs are about 100x that of the fan FET (5110pF vs <64pF).
  • 0

Laine Walker-Avina
Printrbot Beta-tester and Printrboard Designer
lwalkera
Honeycomb infill 25%...
 
Posts: 291
Joined: 2012-Feb-Sat-04-Feb
Location: Folsom, CA
Reputation: 33


Return to Hack talk

Who is online

Users browsing this forum: No registered users and 1 guest

cron