Hi All

I've just built a heated chamber around my home brewed printer. I thought I'd share the config here for reference purposes and for also comments before I actually switch it on, in case I can improve/tweak anything. I have a 400w ceramic heater switched by a solid state relay, and controlled by a semitec (E3D) thermistor. Here's the config. Please feel free to comment. I'll be testing this in a couple of days:

temperature_control.chamber.enable               true               #
temperature_control.chamber.thermistor_pin       0.26          #
temperature_control.chamber.heater_pin           2.6              #
temperature_control.chamber.pwm_frequency        5            # Set low to control SSR 
temperature_control.chamber.thermistor           Semitec       # see smoothie site for details
#temperature_control.chamber.beta                4300              # or set the beta value
temperature_control.chamber.set_m_code           141          #
temperature_control.chamber.set_and_wait_m_code  191   #
temperature_control.chamber.designator           C                #
temperature_control.chamber.bang_bang            true          # set to true to use bang bang control rather than PID
temperature_control.chamber.hysteresis           2.0              # set to the temperature in degrees C to use as hysteresis

I changed the config to use thermistor input 3 instead of 4 and pin 1.22 instead of 2.6 and that seems to have fixed the problem. I have a print running at the moment and the temperature is a reasonably steady 50 degrees. :-)
:
temperature_control.chamber.enable true #
temperature_control.chamber.thermistor_pin 0.25 #
temperature_control.chamber.heater_pin 1.22 #
temperature_control.chamber.pwm_frequency 5 # Set low to control SSR
#temperature_control.chamber.thermistor Semitec #
temperature_control.chamber.beta 4267 # or set the beta value

temperature_control.chamber.set_m_code 141 #
temperature_control.chamber.set_and_wait_m_code 191 #
temperature_control.chamber.designator C #

#temperature_control.chamber.bang_bang false # set to true to use bang bang control rather than PID
#temperature_control.chamber.hysteresis 2.0 # set to the temperature in degrees C to use as hysteresis

I'm using a very slow speed initially (40mm/s) as I'm not sure how the X and extruder steppers will cope with the heat. They seem ok with the 50 Degrees I'm running at for the test, but I'm not sure if I need to up the heat to 70-80 degrees for ABS. Does anyone have any advice on the temperature I should use? I'm printing big parts - 300x300x280mm.

So the print's been running all night. I sneaked a peek this morning and all looked good. I'm going to have to fit a perspex door onto the case so I don't ruin a print by peeking. :-)

Thanks to Arthur for his support in getting this working, and for smoothie in general -such an improvement on the Ramps I started with.

I can't publish pictures, it seems.

I have some shots of the printer, and will soon have some pictures of the results of the heated chamber.

Can I post pics please?

I've sent a couple of shots of the chamber. The inside view and how it looks when closed, plus a print with & without the heated chamber.