Heatbed calibration
Greetings fellow makers,
I am having issues with the calibration of my heatbed on my new i3 mk3s; it fails every time. My xyz calibration is fine, and I’ve checked the heatbed cables over and over, and haven’t seen others with this issue. I have a few more ideas to run through checking to make sure I have continuity in all the connections again. I have turned off all the fans (room not printer) and AC when attempting this step.
I have assisted in putting together several of these printers, but this is my first solo venture. I will update as I continue to try to resolve. If anyone has some direction to go from this point it would be appreciated. Ideas don’t have to be dumbed down too much, I have experience printing and an EE degree.
Thanks so much for any help, and it’s my pleasure to join this forum.
-Mike
RE: Heatbed calibration
I am having issues with the calibration of my heatbed on my new i3 mk3s; it fails every time.
And what is your problem?
Are you getting an error message, or can't you adjust the Z level?
Or is it the bed that doesn't get hot?
Bear MK3 with Bondtech extruder
RE: Heatbed calibration
I am having issues with the calibration of my heatbed on my new i3 mk3s ...
I didn't know the MK3S had a calibration procedure for the heatbed. What page is that in the manual?
RE: Heatbed calibration
Thanks for the quick responses.
I end up with
Checking Bed
———————
X: OK. Y: OK Z: OK
Bed: / Hotend:
Then self test error, please check heater/thermistor not connected
I don’t see this step in the manual, and I believe the printers I’ve worked with before may have been mk3. With them they printed fine without a firmware update, so that may be my next move. I’m confident in my wiring.
Thanks again, will update with my progress tomorrow.
RE: Heatbed calibration
Don't change firmware until you have this sorted out or you may add to your troubles.
Report back on what the two temps are showing on the display after a reset or power on.
Common build error is not connecting the bed leads correctly. Or bending them so they short and blow the 15 amp fuse (or crowbar the PS).
RE: Heatbed calibration
or broken thermister leads on the heatbed
RE: Heatbed calibration
Thank-you all for the insights, quick response and help. Visually all the connections seem correct. I am currently (pun half-way intended) waiting on a new multimeter that’s a bit more full featured.
Thanks and regards,
-Mike
RE: Heatbed calibration
Check the box where all the cable go to, they can come loose wile building, check the connections and that the cables are in the good connector.
RE: Heatbed calibration
I had exactly this same problem. Actually I still have it.
After checking wirings, fuses and thermistor function (with hot air gun) several times prusa support advised me to do full factory reset and flash newest firmware available (3.7.2).
Weirdest part of this is as I was once again testing thermistors with hot air gun, I heated hotend up to 91 degrees celcius. While the hotend was hot, I set temperature from pronterface to 210 C. Suddenly it worked? Then I tested bed and it also magically started working.
I got to print my first print until it failed to temperature runaway. After that I'm again unable to get bed and hotend to warm up. And yes, thermistors work perfectly, I've checked them again.
It seems very unlikely that this is hardware related problem in my case as I got my EINSY replaced already.
RE: Heatbed calibration
Thanks for the idea of testing the thermistors with a heat gun, @hannes. I tested the room temperature resistance of the bed thermistor at 110 ohms, and raised the bed temperature over the thermistor to roughly 100F and it steadily dropped to 40 ohms.
@peter-m26 Thanks for the reply, I have checked all the connections and fuses, and there doesn’t seem to be a wiring issue.
Currently waiting for the next response from CS to see what they make of my situation.
RE: Heatbed calibration
I got my problem solved.
I read somewhere in the forum about faulty/misplaced power panic cable causing similar problem that I had. I immediately went to unplug my power panic cable from both ends and then replugged it in and heating problems disappeared right away.
I got one thermal runaway error shortly after that, but adjusting power panic cable position so that moving heated bed could not cause movement in the cable solved that.
Finally I got to the actual calibration and first prints!
RE: Heatbed calibration
@hannes I’m so glad you got your printer working and I apologize for the late congratulations, my last message didn’t post.
Once I got a replacement einsy it just took a few days of messing with calibration and pinda adjustments to finally get good prints. It may take some more fine tuning, but I’m so happy to have some success.
Thanks to all of you who have helped me get my printer running, I hope I’ll be able to return the favor in the future.
Regards and all the best,
Mike