v0.80.2: Temperature overshoots / printer doesn't start if preheated via Web

xBot150

this is a strange one...

Server: v0.80.2 on rasPi (Install from v80.0/SD and updated)
Firmware: v0.92.?


#1:
I usually pre-heat bed and extruder via Web-GUI to (say B:50 E:210), go grab a beer (or take a leak ;-)) and start the printjob a few minutes later
-> most of the time -7/10 for now, not sure about the other three re preheating vs. just starting the print- the printer homes and sits there (oozing..)
remedy: ESTOP & restart the print -> works

#2:
I'm not sure whether this is related or the cause: setting bed / extruder to B:50 / E:210 (no difference between via gcode or via Web) the temp is usually off +5 degrees, e.g. B:55, E:210 during the whole print and I can't find the cause for this behavior.

xBot150

oops... feel free to move to repetier-firmware and consider me properly shamed&blamed.
/sorry!

xBot150

... turned on the extruder's fan on layer3 (after ~20 minutes with E:215) E:210 and seems to be 'stable' now; bed still at 55.

really strange that...

Repetier

Check you slicer settings. Slicer have first layer temperature and other layer temperatures. If set temperature changes it comes from slicer adding them in gcode. Server just sends these commands.

xBot150

nope, that isn't the cause. If it were some slicer-settings I wouldn't have discrepancies between "Soll" and "Ist" (e.g E: 210/205 B: 55/50) on the display and the Web-GUI.

Repetier

That is true. It is quite normal to overshoot at beginning but then it should go back to correct temperature. In any case this is firmware related as server just sets and reports temperatures. So if this is more then a overshoot you should consider modifying the temperature control settings. The might simply put more power to heater then intended. If you use PID try M303 with params for your firmware (not sure what you are using) to computer better control parameter.

xBot150

M303 P1 S50
and
M303 S200 C5
did the trick, for some reason the autotune-feature within Repetier-Server didn't stick (or did it and caused the overshoot, who knows)

got somewhat confused with M303's output 'cos I didn't know _which one_ to use (indented values are active now) and at least the bed's PID vary quite a bit

-- M303 P1 S50
4:53:06.311: Info:PID Autotune start
4:54:54.902: bias: 91 d: 91 min: 49.91 max: 50.15
4:55:05.452: bias: 93 d: 93 min: 49.91 max: 50.15
4:55:10.664: bias: 79 d: 79 min: 49.91 max: 50.15
4:55:10.667: Ku: 416.18 Tu: 5.21
4:55:10.668: Classic PID
4:55:10.668: Kp: 249.71
4:55:10.668: Ki: 95.80
4:55:10.669: Kd: 162.71
4:55:15.807: bias: 66 d: 66 min: 49.91 max: 50.15
4:55:15.808: Ku: 347.69 Tu: 5.14
4:55:15.811: Classic PID
4:55:15.812: Kp: 208.61
4:55:15.812: Ki: 81.11
4:55:15.812: Kd: 134.14
4:55:24.437: bias: 62 d: 62 min: 49.91 max: 50.15
4:55:24.442: Ku: 326.62 Tu: 8.63
4:55:24.443: Classic PID
    4:55:24.443: Kp: 195.97
    4:55:24.443: Ki: 45.41
    4:55:24.443: Kd: 211.45
4:55:24.445: Info:PID Autotune finished ! Place the Kp, Ki and Kd constants in the Configuration.h or EEPROM
--

and
-- M303 S200 C5
5:03:01.486: Info:PID Autotune start
5:04:53.373: bias: 56 d: 56 min: 197.06 max: 213.68
5:05:28.482: bias: 48 d: 48 min: 196.94 max: 204.93
5:06:02.851: bias: 47 d: 47 min: 196.94 max: 203.77
5:06:02.851: Ku: 8.77 Tu: 34.37
5:06:02.852: Classic PID
5:06:02.852: Kp: 5.26
5:06:02.854: Ki: 0.31
5:06:02.854: Kd: 22.60
5:06:37.005: bias: 46 d: 46 min: 197.29 max: 203.48
5:06:37.009: Ku: 9.47 Tu: 34.16
5:06:37.009: Classic PID
5:06:37.009: Kp: 5.68
5:06:37.010: Ki: 0.33
5:06:37.010: Kd: 24.27
5:07:10.870: bias: 46 d: 46 min: 197.41 max: 203.19
5:07:10.870: Ku: 10.14 Tu: 33.87
5:07:10.871: Classic PID
    5:07:10.871: Kp: 6.08
    5:07:10.871: Ki: 0.36
    5:07:10.872: Kd: 25.75
5:07:10.877: Info:PID Autotune finished ! Place the Kp, Ki and Kd constants in the Configuration.h or EEPROM
--

/and yes, the timestamps are accurate |-)

Repetier

> autotune-feature within Repetier-Server

There is no autotune feature for firmware. Do you mean the temperature wizard to measure heating/cooling speed? That is only used to better compute printing time and has no effect on the real print.

xBot150

yup. one learns something new every day ;-)
-> would be great if this were mentioned enclosed in <blink><font color="red><h1>...</h1></font></blink> 'cos it ain't that obvious.