Heating up bed error since update to RRF 3

lulu3d

Hi all

I just updated to RRF 3.01 rc6, before I was on 2.x, did the necessarily config updates and now I get the error message:

"Error: Heating fault on heater 0, temperature rising much more slowly than the expected 1.7°C/sec"

I know my bed heats up very slowly (330x330 aluminium plate, but that has never been a real deal breaker for me, till now. It takes normally around 15m to go to 60C and that's OK for me.
In the versions before RRF 3.0, I never had this problem ?
Is there a way to change the temperature rising parameter per second, somewhere?! Or other g-code to accept slower heaters?

Thanks for your help

Lucien
Duet Maestro 1.0

droftarts

@lulu3d You need to tune the bed with M303. RRF 3 doesn't have default settings for anything, so it doesn't know that the bed heater is, well, a bed heater, so it applies the standard nozzle settings to the heater, and sees the heater as failing because it heats too slowly.

Basically, send M303 H0 S60. This may take some time, and needs to be done with the bed starting at room temperature to get a good result. After it completes, save the settings with M500. This will create/update the sys/config_override.g file. Then either have M501 at the end of your config.g to load config_override.g, or copy the M307 H0 ... line from config_override.g to config.g to use this heater 'tune'.

More details here: https://duet3d.dozuki.com/Wiki/Tuning_the_heater_temperature_control

Ian

lulu3d

Thanks droftarts for the quick response.

I tried this actually this morning after I got the first warning, but couldn't get a proper result as I get the "Auto tune cancelled because temperature peak was not identified"

I tried this 3 times in a row (M303 H0 S50, as that's my mostly used bed temp), with always the same result. PID tuning the nozzle heater, no problems though

I'll give it another try later

p.s.: I use the simple glass bead sensors. [Y"thermistor" T100000 B4138 R2200]

droftarts

@lulu3d From https://duet3d.dozuki.com/Wiki/Tuning_the_heater_temperature_control#Section_Troubleshooting_auto_tuning

If auto tuning fails with a message that the temperature is not rising fast enough, this indicates that either you are using too low a P value in the M303 command, or the dead time in the existing model is much too low for your heater. You can increase the dead time using the M307 command. For example, sending M307 H0 D30 will increase the dead time to 30 seconds. The actual dead time will be known after a successful auto tuning.

I'd try a really long D parameter, say D60.

Ian

lulu3d

@droftarts said in Heating up bed error since update to RRF 3:

M307 H0 D30

Thank you so much Ian, it worked!
Sorry I must have overlooked this information for myself.

Now I can fine tune it for the better.

Lucien