Pid auto tune

bigwood247

Hi I did a auto tune of my bed and hotend the bed but my hotend tune said warning heater 1 appears to be overpowered its temp is predicted to to reach 464c
Also is said the same thing for the bed ut instead of 464c it was 181c

My m307 h1 reports was as follows : heater 1 model: gain 439.9 time constant 168.0 dead time 2.8 max pwm 1.00 calibration voltage 23.9 mode pid inverted no frequency default
Computed pid parameters for set point change: p24.3 I1.123 D47.7
Computed pid parameters for load change p24

But my power supply is only 12 volt

Anyone know y I'm getting that warning

Phaedrux

You're getting the warning to let you know that your heater could reach that temperature in a failure situation where the controller is no longer in control and full uncontrolled power is applied. It's up to you on how you want to mitigate that. Thermal cut out fuses, fire extinguishers, smoke detector, etc. The get rid of the warning entirely you'd need to choose a less powerful heater.

jens55

Just as an FYI, a LOT of people get these messages (including me) and take it as a warning only. If you were to reduce the power to the bed or hot end(s) the whole thing becomes painfully slow.
I have no additional protections on the hot end but I do have a thermal fuse on the bed.

bigwood247

K thanks alot I knew it wasn't that important cuz it seems to be working fine but thanks for the reassurance

Phaedrux

@bigwood247 said in Pid auto tune:

I knew it wasn't that important

Depends how important your home and belongings are I guess...

bigwood247

But like u stated as long as it doesnt fail it's fine right I mean if u can let me know how to fix it without replacing my stock e3dv6 hotend or bed heater I'm game

bigwood247

Whats a thermal cutout fuse

bigwood247

And also I would think the standard heater for an e3dv6 is fine y would u want a less powerful heater I'm going to be printing hi temp plastics like nylon and polycarbonate

Phaedrux

http://www.be-electronics.com/v/vspfiles/datasheet/nte/thermalCutoff.pdf
https://www.be-electronics.com/product_p/ecg8213.htm
for instance

Phaedrux

@bigwood247 said in Pid auto tune:

And also I would think the standard heater for an e3dv6 is fine y would u want a less powerful heater I'm going to be printing hi temp plastics like nylon and polycarbonate

Well in that case, you obviously wouldn't.

bigwood247

Can u get these fuses say for like 300c plus

Phaedrux

The warning is just there to give you the information. It's up to you do decide what that means for you and how to deal with it. that's all.

bigwood247

K well I'll def look into those fuses but I'll need one for like 310c thanks alot for the info

Phaedrux

@bigwood247 said in Pid auto tune:

Can u get these fuses say for like 300c plus

No. If you look at the PDF it shows the range of temps available, but you don't actually need one that high because you don't have to put it in direct contact with the heater itself, you could put a lower temp one on the heat sink for instance.

zapta

@bigwood247 said in Pid auto tune:

But my power supply is only 12 volt

Are you asking about the warning in general or the reported 23.9V in a 12V system?

BTW, a suggestion to Duet, would be nice if the report will also include the proposed M307 command. Easier to users and less room for error constructing the command manually.

Phaedrux

@zapta The best way to see the properly constructed M307 is to use M500 to save it to config-override, then you can either use M501 in config.g to load it from there, or copy and paste it over if you don't want to use config-override.

bigwood247

@Phaedrux yeah I actually went down that route works good now thanks