MK4 layer shift & collision detection
Hello All, I am on my third MK4. The previous 2 printers were replaced under warranty (all factory assembled).
I am having a very frustrating issue with layer shifting on all MK4's I have owned. I am using Prusa Matte Black PETG with the generic PETG profile (non IS). Single parts print flawlessly. However, when I print multiple parts I get layer shifting occuring.
I have noticed the extruder at some point leaves a big glub, eventually causing an extruder collision and shifting off axis. I dont believe the MK4 has collision detecting so the printer just continues printing and wasting filament despite the print failing.
It appears the MK4 does not have collision detection which is absurd? Is this feature going to come in future firmware?
I posted in the Prusa group on facebook and it appears many others have this same issue.
Would love to hear people thoughts on this. I have been trying to contact prusa support but chat times are 40+ minuted to speak with a service consultant.
RE: MK4 layer shift & collision detection
Any news on this?
Even though it's probably unrelated, I feel like the pressure sensor is waaaay underutilized and that it could do a lot more things, scuh as detecting spaghetti situations because there would be absolutely no resistance when extruding.
RE: MK4 layer shift & collision detection
Yes, please re-enable collision detection! Since upgrading my MK3's to MK4, I'm no longer able to trust my printers to be able to complete parts with support material reliably, I'm thinking about putting them back to MK3 it has gotten so bad. It's just not worth having the nice features of the MK4 if I can't do what the MK3 was able to. 🙁
RE: MK4 layer shift & collision detection
I've had recurring problems with both X and Y layer shifts on my kit MK4. Printed fine for a couple of weeks and then had sporadic issues - the problem was belt tension. But, I'd redone the belts with the tuner app multiple times - how was it still an issue?
I printed the physical Prusa belt gauge ( https://www.printables.com/model/46639-tension-meter-for-the-gt2-belts-of-i3-mk3s-or-prus) in Prusament PETG, reset the X- and Y-belts again and torqued the living hell out of the X-motor retention screws and the Y-tensioner fixing screws. Advice on pressure be damned, those things were twisted to within an inch of their lives. I also re-aligned the X motor pulley to center the belt on the pulley better. Zero layer shifts or tension movement since then. The nice thing about the Prusa gauge is that you can just clip it on to check tension without having to rely on black magic readouts from the (kind of inconsistent) app.
RE: MK4 layer shift & collision detection
Yes, I do have a crash every once in a while: a blob forms on the print and the nozzle hits it, the part warps and the nozzle hits it etc....
I would be very pleased to have crash detection as an option. If it false triggers due to input shaping, I want the printer to do an XY home to check if the crash really happened: if the home position is 0,0 then continue the print else stop and beep loudly.
RE: MK4 layer shift & collision detection
How about using the load cell on the nozzle as well as the crash detection from the motor drivers for confirming a crash, the nozzle is cone-shaped so when a major crash happens there should be a pressure spike on the load cell...
RE: MK4 layer shift & collision detection
that's a possible option, however the developers rarely come here, this is more of a Peer to Peer forum.
I Suggest that you visit the Mk4 Github pages, have a search to see if the idea has already been raised, in which case you can add your support to the idea, and if it's not been raised, you can create a new request,
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK