Posts made by AlexZ.

My custom printer was down for a couple of months, I made some mods to it and didnt have the time to tune/configure it. Last weekend I finally got around to getting it running again. The controller is a duet 2 wifi running the latest release firmware: 3.4.6, with a single hot end. part of my rebuilding I changed the heat cartridge and the thermistor.

The printer seemed to pick up right where I left it, but in my last couple of prints I have had heater failures on E0. The weird thing is they are over temp warnings. generally, 20+ degrees over what it is set at. I have been able to reset the fault, bring the hot end temp back up, and resume the print. it runs for another 30 minutes to 4 hours, and then it faults again with the same error, 15-20 degrees over for 5 seconds. When it faults it successfully shuts off the heater.

The heat cartridge and thermistor are new and came from slice engineering. I put a new nozzle on when I got the printer running again and ran a PID tune which was successful.

I am wondering if this is a sign that the mosfet on e0 is going bad? Or is there something else I should suspect? I was planning on changing it so the cartridge was plugged in to the e1 heater instead… but before I do, I wanted to know if there is anything else I should suspect.

has anyone attempted to hook one of these up to a duet yet? i'm sure the hardware has some open GPIO pins that could be used, but i dont think the software supports a live heigh readout. it would be nice to have another option in z sensors.

https://github.com/markniu/Bed_Distance_sensor

@OwenD @bearer
ahh! i get what you are saying! my solution would detect a blown fuse... but all i really care about is weather the heat sink cooler is dead.. and it can fail either closed or open, blowing the fuse or not... but with daemon.g i can actually monitor it and take action. thank you guys so much!

as an aside... the mosquito is really really really efficient even without a fan. my heat brake has a clog in it, and i followed this procedure https://forum.prusaprinters.org/forum/original-prusa-i3-mk3s-mk3-user-mods-octoprint-enclosures-nozzles-.../mosquito-clearing-a-heat-creep-jam-easily/, trying to melt the clog in the tube... i totally removed the mosquito from my hot end mount so nothing was blowing on it and using the duet control i set the temp at 270... it heated up and maintained temp without a thermal runaway for a good 5 minutes. by then the heat sink was too hot to touch... but there was no thermal runaway... it stayed at 270.. and also did not melt the clog.... either way....

thanks again!

whereas i know you can monitor the tach of the fan, i didn't find where you could generate a fault if the tach falls to zero... and i think i read that @dc42 said the tach is only accurate if the fan is running at full speed. i am looking for something automated... so if i am printing and not watching the printer it will stop instead of causing issues. it is a corexy design printer... so if anything on an emergency stop the bed will fall away instead of the head crashing into the print. and i think i can define an action or a macro to be run with M581 so that it will shut down the heater and move to x0, y0.

I have a duet 2 wifi in a heavily modified tronxy printer. It has a mosquito hot end. One of my part cooler fans shorted out and blew the fan fuse. The weird thing is It did not shut down from thermal runaway, and the heat sink was handling it pretty well... Until the screws holding it to the mount melted the plastic (it was printed out of petg). I was at my printer when I noticed the hot end was suddenly loose and shut it off before there were any issues.

I have replaced the fuse, fans, and mount and am up printing again. I would like to put in a failsafe so hopefully this can be caught before it happens again... I was thinking of putting a 24v normally closed relay on one of the always on fan headers and put the switch on the emergency stop header... I figure when the printer starts, the relay will get power and open the switch. If the fuse blows, the relay will loose power and the switch will close where I can trap the emergency stop and hopefully shut the hot end off before it melts the mount.

I searched the forum but did not find anyone doing this or having this issue.