Prusa Crash Detection error And then Crashes Its self
I got my Prusa i3 MK3s+ a few months ago and I really like printing with it. I am very happy with the reliability and quality of the machine but I have experienced a few quirks with it and one just happened that worried me a bit so I am going to describe it:
Just recently I had stopped a print because of some excessive stringing and then I set the extrude to extrude 20mm of filament (I believe the machine considers that action doing a print) to purge the nozzle a little and while it was doing that I removed the part from bed and removed the skirt. My arm gently touched the bed and then the printer kind of freaked out. It did the crash detection movement where it jumps up like 5 mm in z and then restarted the printer. It then said crash detected and then homed x and y and then violently started running the x axis into the end and kept skipping steps. I don't know why it decided to move lower than x0 or why crash detection did not go off when it did that. I noticed it seems to react to me touching the bed sometimes but not always.
Does the machine have a way of detecting a person touching the bed which could cause that and has anyone had an issues like this before?
RE: Prusa Crash Detection error And then Crashes Its self
Do you get a lot of static electricity build up? This sounds like some sort of spike deranged the programming...
Check your earthing. Get into the habit of grounding yourself before touching the printer.
Cheerio,
RE: Prusa Crash Detection error And then Crashes Its self
Rub feet across shag rub holding baloon, touch cat. Cat crashed into the printer and fried the Einsy board. Should I rub my feet more on the carpet?
Oh, by the way, touching the bed during the mesh bed leveling - it indeed does know you are touching it and will sort of freak out. Keep yer hands away and the cat too.
RE: Prusa Crash Detection error And then Crashes Its self
When you touch the bed when it is moving, your are stalling the stepper motor. This causes a spike in current the drivers detect. Once stalled, the printer has no idea where the nozzle is at and must be auto-homed before continuing. This means aborting any print in progress.
RE: Prusa Crash Detection error And then Crashes Its self
@diem
Thats a good idea. My printer is in a room where the floor is carpet but I usually dont consider grounding myself. Is there a good way to do that?
RE: Prusa Crash Detection error And then Crashes Its self
@dan-rogers
Oh boy ill keep an eye on it because I dont want to mess that board up. Expensive replacement!
RE: Prusa Crash Detection error And then Crashes Its self
@tim-2
That may have been it. I could have like forced the y axis to move when I removed the part
RE: Prusa Crash Detection error And then Crashes Its self
@julian-6
Once a print is done, I almost always move the bed. Very hard not to. But when the next print starts, the printer homes, which resets all the positional data. Unless you are doing manual moves using the menus between prints after you've bumped it; it shouldn't be crashing the nozzle into the bed.
Then there's the back-emf issue: if you bump the bed hard enough (or the extruder) and it moves a small distance, the motor becomes a generator that back feeds current into the drivers. This spike could cause some issues - unlikely to damage the Einsy, but enough to make it go whacko until you do the big X reset.