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Workaround - I changed my extruder heat control to setting 3 and calibrated for dead-time using http://www.repetier.com/dead-time-control/ .

Just finished building my Rostock Max v2 and am trying to run the PID tuning (M303 S200, per my manual) and the issue I am having is that the printer hits the set temperature and just keeps heating. This also fails the autotuning due to high temperature. The displays tick up as it heats and track increases and decreases correctly as far as I can tell, but it does not stop after reaching the set point.
It will do the same if I tell it to set a temperature. I have tried restarting the printer and reuploading the firmware (repetier v091 reads as 091s on my LCD) I am using MatterControl 1.4 and Repetier-Host 1.6.
I have tried multiple temperatures between 45C-200C with the same results. I also dropped the Extr.1 PID max value to 128. Can someone suggest next steps to try? My research suggested that it was likely a firmware issue but that I couldn't rule out hardware. I am not sure where to approach the hardware side from; if the temperature is being measured accurately (even if not, it reads like it hit the set point on the LCD and in MatterControl) I would think that would stop it unless it is measured elsewhere as well. Help is very much appreciated.
So far I have tried:
* Restarting the software and printer
* Picking different temperatures for the hot end heating
* Reducing the hot end power to slow the heating in case it was just overshootingtoo far and fast (values 80 and 128 tried)
* Trying different control software (MatterControl 1.4 and Repetier-Host 1.6)
* Reuploading firmware to the Rambo
In progress / to-do:
* Check all hot end and temperature related wiring
* disassemble hot end and check thermistor connections, resistance readings, and RTV

You're seeing an overshoot at 128? I don't think that's even possible.

g.

I think there were example settings for PID in the manual. Start with those. The ones you have sound wildly off. PID max is a Band-Aid.

Should you be making changes to EXT_0 instead of EXT_1...

Earthbound wrote:Should you be making changes to EXT_0 instead of EXT_1...

In my EEPROM menu there is only EXT.1.

IMBoring25 wrote:I think there were example settings for PID in the manual. Start with those. The ones you have sound wildly off. PID max is a Band-Aid.

My present values match the ones in the manuial screenshot exactly. Though it doesn't match the averages you get if you base it off the screenshot of the autotune completion. I will try working toward those values. Failing there I am going to try making small changes in PID values based on the tables in the Wiki page.

geneb wrote:You're seeing an overshoot at 128? I don't think that's even possible.

g.

Would that suggest that the thermistor is overreacting to the heat it is detecting? Possibly a short in the system?

I checked the Rambo wiring and round the extruder motor connector was backwards but the rest looks good, including the thermistor connectors. When it cools again I am going to undo the hot end and see what I can find.

I also tried setting the temperature of the bed and hot end with Gcodes and letting it run, and it still went past, but it did let power off and maintain the temperature within 2C of the set point during the test. I feel like this points more toward a software/firmware interaction issue than a hardware issue.

It seems like it works properly when the Target: readout on the LCD shows my set point. When I run the M303 for tuning it does not show a set point there and it blows past the set temperature until it is 20C over and the test fails. Should my LCD be showing Target: (temp I put in S) when I run M303?

So I still haven't solved this issue, but I was able to move on to calibrate and then print my PEEK fan holder! If a few of you fine folks want to share some PID values so I can see about just basing mine off of yours it would be appreciated.

I did hit a new issue though. Mattercontrol tries to start printing about 4 inches off the build plate, but repetier host starts rights where it should. Can I fix that with the Z endstop correction in the configuration?

Fix it in MC where it is broken. If R-H works, then printer configuration is good.

blackrabt wrote:So I still haven't solved this issue, but I was able to move on to calibrate and then print my PEEK fan holder! If a few of you fine folks want to share some PID values so I can see about just basing mine off of yours it would be appreciated.

I did hit a new issue though. Mattercontrol tries to start printing about 4 inches off the build plate, but repetier host starts rights where it should. Can I fix that with the Z endstop correction in the configuration?

My fix for the Mattercontrol issues, was to just quit using it.

Mac The Knife wrote:

blackrabt wrote:So I still haven't solved this issue, but I was able to move on to calibrate and then print my PEEK fan holder! If a few of you fine folks want to share some PID values so I can see about just basing mine off of yours it would be appreciated.

I did hit a new issue though. Mattercontrol tries to start printing about 4 inches off the build plate, but repetier host starts rights where it should. Can I fix that with the Z endstop correction in the configuration?

My fix for the Mattercontrol issues, was to just quit using it.

I think that will be my fix as well.

Well, I wish you'd found an answer. I'm having exactly this problem... How did you get up and running?

to be more clear... my hot end temp just keeps climbing and climbing. Looks like maybe it isn't reading the value in EXT.1

If you stopped using matter control, what did you start using?