26 Reply by gary2169

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Re: Replacement Heat Core - new design

I am having similar problems with temperature stability. Extrude temps consistently overshoot both heating and cooling by 15 degrees or more. Trying to print PLA at 185C as soon as the skirt start to print the nozzle temp drops below 170, and the extrusion cuts off (but repitier DOESN'T pause or abort the print!). If I jack it up to 190-195, it doesn't cools below 170 and stop extruding, but the PLA softens enough at the cold end to bend and wrap around the drive wheel, and jam the whole works.

I have done the PID recalcs - multiple times at 185, and the numbers come back consistent. The damn thing just can't hold within a 15 degree range.

Suggestions?

27 Reply by cmetzel

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Re: Replacement Heat Core - new design

thermistor secure?

28 Reply by lobosolo

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Re: Replacement Heat Core - new design

I am still having the temp swings as well. I contacted solidoodle support who told me that it if its not affecting the prints, then it should be fine. mine has 20 degree temp swings up and down 10 degrees. when i look at the temperature tab (set to 190) it looks like a sinewave just up and down 180 to 200.  yes i have the Thermistor securely attached.

29 Reply by cmetzel

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Re: Replacement Heat Core - new design

You've got to wait for an elmoret or lawsy response or someone else that can debug electronics.  That's my weak point.

30 Reply by ronsii

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Re: Replacement Heat Core - new design

Hi Gary and Lobo, Can you post the last PID numbers you programmed the SD with?

31 Reply by lobosolo

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Re: Replacement Heat Core - new design

ronsii wrote:

Hi Gary and Lobo, Can you post the last PID numbers you programmed the SD with?

sure thing.
i run this in RH after i set the temp to 190

M303 S190 C5

let it cycle until it gives me the PID output which is this


M301 P9.34 I0.31 D70.06

everything looks good so i run

M500

close, unplug restart and i get this
the PID settings are not staying saved.


09:07:41.885 : echo: Free Memory: 1453  PlannerBufferBytes: 1232
09:07:41.885 : echo:Using Default settings:
09:07:41.885 : echo:Steps per unit:
09:07:41.885 : echo:  M92 X88.00 Y88.00 Z2268.00 E138.00
09:07:41.885 : echo:Maximum feedrates (mm/s):
09:07:41.885 : echo:  M203 X500.00 Y500.00 Z5.00 E45.00
09:07:41.885 : echo:Maximum Acceleration (mm/s2):
09:07:41.885 : echo:  M201 X9000 Y9000 Z100 E10000
09:07:41.885 : echo:Acceleration: S=acceleration, T=retract acceleration
09:07:41.885 : echo:  M204 S3000.00 T3000.00
09:07:41.885 : echo:Advanced variables: S=Min feedrate (mm/s), T=Min travel feedrate (mm/s), B=minimum segment time (ms), X=maximum xY jerk (mm/s),  Z=maximum Z jerk (mm/s)
09:07:41.885 : echo:  M205 S0.00 T0.00 B20000 X20.00 Z0.40 E5.00
09:07:41.885 : echo:Home offset (mm):
09:07:41.885 : echo:  M206 X0.00 Y0.00 Z0.00
09:07:41.885 : echo:PID settings:
09:07:41.885 : echo:   M301 P22.20 I1.08 D114.00
09:07:41.920 : N6 M105 *1
09:07:42.125 : ok
09:07:42.150 : FIRMWARE_NAME:Marlin V1; Sprinter/grbl mashup for gen6 FIRMWARE_URL:https://github.com/mlaws/solidoodle2-marlin PROTOCOL_VERSION:1.0 MACHINE_TYPE:Solidoodle EXTRUDER_COUNT:1
09:07:42.150 : ok
09:07:42.150 : N7 M220 S100 *70
09:07:42.150 : N8 M111 S6 *79
09:07:42.155 : ok T:68.7 /3.0 B:46.7 /3.0 @:0

32 Reply by ronsii

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Re: Replacement Heat Core - new design

lobosolo wrote:
ronsii wrote:

Hi Gary and Lobo, Can you post the last PID numbers you programmed the SD with?

sure thing.
i run this in RH after i set the temp to 190

M303 S190 C5

let it cycle until it gives me the PID output which is this


M301 P9.34 I0.31 D70.06

everything looks good so i run

M500

close, unplug restart and i get this
the PID settings are not staying saved.


09:07:41.885 : echo: Free Memory: 1453  PlannerBufferBytes: 1232
09:07:41.885 : echo:Using Default settings:
09:07:41.885 : echo:Steps per unit:
09:07:41.885 : echo:  M92 X88.00 Y88.00 Z2268.00 E138.00
09:07:41.885 : echo:Maximum feedrates (mm/s):
09:07:41.885 : echo:  M203 X500.00 Y500.00 Z5.00 E45.00
09:07:41.885 : echo:Maximum Acceleration (mm/s2):
09:07:41.885 : echo:  M201 X9000 Y9000 Z100 E10000
09:07:41.885 : echo:Acceleration: S=acceleration, T=retract acceleration
09:07:41.885 : echo:  M204 S3000.00 T3000.00
09:07:41.885 : echo:Advanced variables: S=Min feedrate (mm/s), T=Min travel feedrate (mm/s), B=minimum segment time (ms), X=maximum xY jerk (mm/s),  Z=maximum Z jerk (mm/s)
09:07:41.885 : echo:  M205 S0.00 T0.00 B20000 X20.00 Z0.40 E5.00
09:07:41.885 : echo:Home offset (mm):
09:07:41.885 : echo:  M206 X0.00 Y0.00 Z0.00
09:07:41.885 : echo:PID settings:
09:07:41.885 : echo:   M301 P22.20 I1.08 D114.00
09:07:41.920 : N6 M105 *1
09:07:42.125 : ok
09:07:42.150 : FIRMWARE_NAME:Marlin V1; Sprinter/grbl mashup for gen6 FIRMWARE_URL:https://github.com/mlaws/solidoodle2-marlin PROTOCOL_VERSION:1.0 MACHINE_TYPE:Solidoodle EXTRUDER_COUNT:1
09:07:42.150 : ok
09:07:42.150 : N7 M220 S100 *70
09:07:42.150 : N8 M111 S6 *79
09:07:42.155 : ok T:68.7 /3.0 B:46.7 /3.0 @:0

Does the M500 command return with a 'settings saved' acknowledgment?

33 Reply by lobosolo

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Re: Replacement Heat Core - new design

ronsii wrote:

Does the M500 command return with a 'settings saved' acknowledgment?

Yes  and I just rebooted and the setting appeared to be saved.  in RH the eeprom setting appear to have the correct numbers as well.

everything now looks good, except the sinewave looking heat fluctuation.

like this https://lh6.googleusercontent.com/-TJJ4RiW6jhA/UWBqEy6ICtI/AAAAAAAAG9I/YKRIO-qIojo/s697/photo.JPG

34 Reply by Tomek

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Re: Replacement Heat Core - new design

though this doesn't explain why you're having your problem, you could manually change those values. the autotune suggested for you:
P9.34 I0.31 D70.06

By comparison, my values are
34.84, 4.39, 69.08. 

[You can expect I'll have a little bit more overshoot than you, since my Kp value is so high.]

Your values seem reasonable for everything except for I. I is integral control, and responds based on how much error from your target that you have accumulated over time.


I would recommend upping it to 2. That should get into the ballpark where you should be able to get rid of the oscillations, without causing many problems.  You can also try increasing it to 1, seeing if that helps, then 1.5, then 2. But you may as well just jump to 2.

Summary: I was going to suggest you increase the  I term, because I term tends to remove oscillations. This being a maybe reasonable idea is further supported by the fact your I term is set to 10x less than mine.  You can easily edit the EEPROM settings in the repetier software when connected to your printer.