Extruder Temperature Control
Posted: Thu Nov 07, 2013 8:50 pm
I am pleased to say I have progressed with my Ord Bot build and I have now had some successful prints with ABS. I am still a newbie but maybe moved up to a level 2 newbie now.
One or two things still giving me grief. One of which is an occasional overtemp problem on the extruder. I usually print in stand alone mode (Arduino mega 2560/Marlin/Ramps 1.4/Slic3r) direct from the SD card. I do this because of Repetier freezing when controlling direct from the PC, but that is another problem. Printing direct from the SD usually works reliably but occasionally it goes overtemp sometimes during printing and also during the initial heatup.
I raised the overtemp limit to 245C in Marlin. I have a hotends.com Jhead and the temp limit for peek is 247C so very close. I autotuned the temp control to get the PID values. I repeated it for consistency and I put the new values into Marlin. I run the extruder usually at 230C for ABS. I would run at 235C if I could. I also altered the temp band when the heating comes on full. It was 10C originally and I widened this to 15C to help prevent the temp overshooting. All these changes helped reduce the frequency but it occasionally still does it. When it happened last time, I had the set point on 235C and it peaked at 247C and cut out. There was no thermal load on the extruder. It was during the preparation stage before printing.
Any suggestions would be appreciated.
One or two things still giving me grief. One of which is an occasional overtemp problem on the extruder. I usually print in stand alone mode (Arduino mega 2560/Marlin/Ramps 1.4/Slic3r) direct from the SD card. I do this because of Repetier freezing when controlling direct from the PC, but that is another problem. Printing direct from the SD usually works reliably but occasionally it goes overtemp sometimes during printing and also during the initial heatup.
I raised the overtemp limit to 245C in Marlin. I have a hotends.com Jhead and the temp limit for peek is 247C so very close. I autotuned the temp control to get the PID values. I repeated it for consistency and I put the new values into Marlin. I run the extruder usually at 230C for ABS. I would run at 235C if I could. I also altered the temp band when the heating comes on full. It was 10C originally and I widened this to 15C to help prevent the temp overshooting. All these changes helped reduce the frequency but it occasionally still does it. When it happened last time, I had the set point on 235C and it peaked at 247C and cut out. There was no thermal load on the extruder. It was during the preparation stage before printing.
Any suggestions would be appreciated.