First layer issues - sudden change in behaviour
Hi there,
I've done 6 or so prints on the freshly assembled printer and the first layers have been great and looked like what I would expect. Originally I had the z offset too low and the first layer was crunchy but after a few tests I got a value that matched the manual / etc. I went to re-print an object last night and suddenly the first layer looked really bad, it's like the printer has a hangover. Attached is what Prusa Slicer shows and what the layer on the bed looks like. The solid infill misses the perimeters at times. Also attached is the Prusa logo, one printed two days ago and one printed this morning.
I have reset the calibration and also did a cold pull but so far no improvement. Both of these are using Prusa filament.
Any suggestions I will gladly try, thank you!
RE: First layer issues - sudden change in behaviour
I think we need some more information.
What print surface are you using?
From the pictures the bad ones are a different filament than the good ones.
What filaments are you using and what temperatures are you printing at?
And maybe print a 2.5" or so calibration square with the bad filament and let us look at it.
RE: First layer issues - sudden change in behaviour
@robert-rmm200
Thanks Robert!
I could have been more specific. I was printing fine with the red prusament, I went to re-print the last object after it had finished and started getting the alignment issues. What I forgot to mention that on the previous print (pre-alignment issues), a piece had come loose and the printer complained of a crash issue a couple times and parked itself before resuming printing on its own.
I also tried printing the prusa logo in galaxy silver about an hour ago and got the same issues. For all the prints I was using the standard pla temperature.
Is there an stl that you would recommend for a calibration square or can I make one?
Thanks for your help!
RE: First layer issues - sudden change in behaviour
Above is the first print from the printer.
Middle is what is happening now, I re-printed it with Galaxy Silver and it shows the same errors in the same places. Oh the mystery
RE: First layer issues - sudden change in behavior - SOLVED
Mystery solved. Once I could rule out filament / nozzle issues I inspected the motors. The pulley on the Y axis had come loose on the motor shaft. I must've not tightened it enough. Now it is back to printing correctly.
RE: First layer issues - sudden change in behaviour
Mauricio,
Let's see if I can beat bobstro and Robert-rmm200 with my reply 🙂
When you are tightening the pulley screws it is important to do so in the following order.
1. Loosen both screws
2. Rotate the pulley so that one screw is aligned with the flat on the shaft and tighten it.
3. Tighten the remaining screw
Failure to follow this sequence will result in the pulley working loose again in short order.
Happy printing,
Steve
RE: First layer issues - sudden change in behaviour
Thanks Steve, that’s an excellent tip!
RE: First layer issues - sudden change in behaviour
At this point, half the Prusa world seems to use the calibration square in this topic:
RE: First layer issues - sudden change in behaviour
Mystery solved. Once I could rule out filament / nozzle issues I inspected the motors. The pulley on the Y axis had come loose on the motor shaft. I must've not tightened it enough. Now it is back to printing correctly.
If you don't follow the FLAT FIRST rule, the set screws will come loose. Loosen both set screws; align and tighten the first setscrew on the flat; then, and only then, tighten the second set screw. This acts as a jam nut to the first setscrew, locking it in place. To remove, loosen the setscrew on the round before the one on the flat or you risk stripping it.