Printer freezes at start of print

jumpedwithbothfeet

Phaedrux

Ok, so G32 is ultimately just running G29

; bed.g
; called to perform automatic bed compensation via G32
;
; generated by RepRapFirmware Configuration Tool v2.1.8 on Mon Apr 06 2020 18:55:28 GMT+0100 (British Summer Time)
M561 ; clear any bed transform
G29  ; probe the bed and enable compensation

jumpedwithbothfeet

@Phaedrux so changing the slicer to G32 wont work?

Phaedrux

@jumpedwithbothfeet

You can try. It will just cause it to probe the whole bed surface before printing.

The G29 S1 that you had in there already was loading a saved heightmap (from the last time you ran G32)

Either way, it would appear that there is a bug that is causing a hang when loading a heightmap. So maybe probing a fresh heightmap will behave differently than loading a saved one.

jumpedwithbothfeet

@Phaedrux Yup just found that out! I'll run a fresh bed map and see if it changes anything, is this something the new firmware update will likely address?

Phaedrux

@jumpedwithbothfeet said in Printer freezes at start of print:

is this something the new firmware update will likely address?

Yes, the full releases of 3.01 is on the horizon with much work going into DWC and DSF.

I suggest digging into the DWC/DSF release threads to see how it's progressing and what else is being reported.

https://forum.duet3d.com/topic/15343/dsf-1-3-1-unstable-released/
https://forum.duet3d.com/topic/15342/duet-web-control-2-1-1-released/

jumpedwithbothfeet

@Phaedrux @PaulHew Ok so I ran the new bed map, actually I ran it twice is I forgot to heat the bed and nozzle, amazing what a difference that makes to the level, but any way it worked it's printing! ill run some test prints again tomorrow hopefully it was the cause, thanks again for all your help and your time

PaulHew

@jumpedwithbothfeet if you need to ask me anything before @Phaedrux gets online, you have my details and am more than happy to help further.

I think I need to get a duet3 now so I can understand it better and put it on the Railcore.

Regards
Paul

jumpedwithbothfeet

@PaulHew I have to say even tho it’s taken over a week to get something printed and that’s mainly down to user induced faults! I still feel like I’ve got out of an escort and jumped into a Ferrari with this board, all I’ve got to do now is learn how to drive

jumpedwithbothfeet

@PaulHew @Phaedrux, so I have some feedback about this issue, I’ve managed to do multiple prints today which I’m very happy about, and I’ve figured out the bug.

Every time the printer is turned off and restarted the height map won’t apply, it loads and displays but that’s it, once a G32 has been carried out again you can print back to back with no hang ups until you turn the printer off, now I don’t have power off resume added to my config.g so I can’t test it but if a power loss occurs I would assume a restart print wouldn’t be able to be done.

Another thing I’ve noticed is on start up the hot end is always active wouldn’t it be safer to default it “off”?

Cheers Jim

PaulHew

@jumpedwithbothfeet Hi Jim, can you post your latest config.g please.
Just realized what you are referring to.

Unless a temp value has been selected, either manually or by Gcode, it will not heat.
Its just ready to go is the way I view it.

If the 'Turn Everything Off' was working no disrespect to the cleaver people, it will go into 'Off' state.

As @Phaedrux said, there is a new release of RRF3 coming out soon along with a new DWC also.

Glad you are printing again, how are the prints coming out?

Regards,
Paul

jumpedwithbothfeet

@PaulHew, Hi Paul, I printed a calibration cube and that was an abomination but I also printed a model and that came out brilliantly, I'll be running through some more calibration tomorrow and try and get it dialled in further.

config.g

Regards Jim

PaulHew

Hi Jim,

Its worth doing this if you havent already

Heater tuning
https://duet3d.dozuki.com/Wiki/Tuning_the_heater_temperature_control

Regards
Paul

Phaedrux

@jumpedwithbothfeet said in Printer freezes at start of print:

Another thing I’ve noticed is on start up the hot end is always active wouldn’t it be safer to default it “off”?

How it behaves at startup is entirely up to you. Typically though, there is a G10 command in config.g which sets the tool active and standby temps to 0 (off) and then a T0 command which sets the main tool as active, so that when you send a temp it starts to heat.

For example, from your config.g

G10 P0 R0 S0                                ; set initial tool 0 active and standby temperatures to 0C

; Custom settings are not defined

; Miscellaneous
M501                                        ; load saved parameters from non-volatile memory
T0

If you didn't have those commands, the starting temperature would show up as -273, which can be confusing, and you'd have to manually enable the tool by clicking it active in the web control or sending a T0 command manually or in your slicer start gcode.

jumpedwithbothfeet

@Phaedrux ahhh I get you so there is no way the tool even tho marked as active could have a temperature other than 0 applied, so for arguments sake and bearing in mind my electrical education is sorely lacking, if their was a fault with the hot end thermistor on start up the hot end could have heat applied?

so to counter this if I uncomment the G10 line the tool would start up in "off" but with a temp reading -273 until the tool is made active?

@PaulHew yup I have carried out the AutoPID on both bed and heater, however you have just reminded me that I did the hot end with out the part cooling fan on and the nozzle heat line was a little bumpy during printing yesterday so ill do it again with it on!

Regards Jim

Phaedrux

@jumpedwithbothfeet The heater is starting in an off state as it is. 0 is off. The tool is active. As in selected and ready. It won't heat unless you give it a temperature target in some way.

If a thermistor fault happened it would detect an abnormal temp change and halt with an error. If the heater itself faulted into the on position and started to heat on it's own the duet would detect that too and try to stop it if possible, but if it was truly faulted as a closed circuit with full power there's not much you could do other than a thermal cut out.

So in short, the real failure situation requires either a heater that is only powerful enough to get hot enough to melt the filament but not hot enough to melt the aluminum heat block. Or a thermal cut out to cut power entirely to the heater cartridge if the temps got too hot.

Those risks and solutions are the same regardless of if the tool is selected at start up or not.

So you're right to be worried but you're worrying about the wrong thing.

Never leave the printer unattended while powered on. Have a smoke detector and fire extinguisher handy. Choose heater wattages reasonable for the task. Install thermal cutouts where possible. Use ground fault interrupters on the AC outlets. Use a fused power switch. Ground the frame. All that sort of stuff is what's going to make the difference for safety.

jumpedwithbothfeet

@Phaedrux Thank you for the explanation, the only thing I don't have are the fire extinguisher and thermal cut outs which I'll look into further but I've not found anything suitable on that front yet as I'm assuming it would need to be mounted on the hot end

Regards Jim

Phaedrux

thermalCutoff.pdf

This might help.

The issue with cutouts on the hotend is that you can't really find a cutout that would survive long term at the temps we print at, so you need to attach a lower temp one to the heatsink instead. It also requires cutting into the heater wiring, which needs to be done properly to prevent a short from happening.

jumpedwithbothfeet

@Phaedrux thanks I’ll take a look see if I can source in the uk.