Layer shifting
Finally finished the build, worked through a couple of minor issues in the configuration wizard, was super excited to get started printing. The first print (the Prusa logo included on the card) came out fine. Second print (3DBenchy also on the card) had a couple of layers shifted. Third print was https://www.thingiverse.com/thing:925556 and it had a few shifts (of a layer or two, then back) toward the bottom, then went twelve hours before shifting over far enough to completely ruin the part.
I searched the forums, saw some mention of shifting on b150, so I reflashed the firmware to 3.1.1. Tried again with 3DBenchy, and canceled the print after seeing another bad layer shift.
In fact, when I popped the print off the bed, I saw that the second layer had shifted (particularly visible in pic #2 below).
Pics:
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As it currently stands, this $750 printer is unusable. What can I do to fix it?
Re: Layer shifting
Oh, I forgot to mention: so far, all of the shifts have been along the X axis.
Re: Layer shifting
Both worm screws on X-axis 623h bearing with housing are OK and tight as well?
Re: Layer shifting
I'm not sure what "worm screws" refers to, but I tugged on the belt and the bearing looks solid. Support -> Belt status says X: 250; Y: 248 for whatever that's worth.
Re: Layer shifting
I'm not sure what "worm screws" refers to, but I tugged on the belt and the bearing looks solid. Support -> Belt status says X: 250; Y: 248 for whatever that's worth.
Check the set screw that keeps the pulley from rotating relative to the motor shaft. Even a slight amount of wiggle can give layer shifts, and if it wasn't totally tight to begin with the screw can work its way out.
Re: Layer shifting
Disable crash detect.
Re: Layer shifting
I tried disabling crash detection—no difference.
Re: Layer shifting
Check the set screw that keeps the pulley from rotating relative to the motor shaft. Even a slight amount of wiggle can give layer shifts, and if it wasn't totally tight to begin with the screw can work its way out.
Hooboy. I was hoping I wouldn't have to disassemble the X-axis, but I'll take a look soon. Thanks!
Re: Layer shifting
Check the set screw that keeps the pulley from rotating relative to the motor shaft. Even a slight amount of wiggle can give layer shifts, and if it wasn't totally tight to begin with the screw can work its way out.
Hooboy. I was hoping I wouldn't have to disassemble the X-axis, but I'll take a look soon. Thanks!
Assuming we are talking X axis, you dont have to dismantle anything to get to the pully grub screws.
Re: Layer shifting
Assuming we are talking X axis, you dont have to dismantle anything to get to the pully grub screws.
I'm looking at my MK3 and the pulley screw is directly behind the threaded Z-rods. I don't see any way to get an allen key in there. What am I missing?
Re: Layer shifting
Assuming we are talking X axis, you dont have to dismantle anything to get to the pully grub screws.
I'm looking at my MK3 and the pulley screw is directly behind the threaded Z-rods. I don't see any way to get an allen key in there. What am I missing?
I may be completely misunderstanding this.. But you want to look at the pulley on the end of the motor shaft.. If its loose, the motor can turn and the belt not.. I think thats what you are ment to be checking.. Appologies if I have it all wrong.. If so, just ignore me.
Re: Layer shifting
You can remove the z-axis-top part (witch fixes the threaded Z-rods and the smooth rods on the frame), them remove the black Trapezoid nut screws and nut... then you unscrew the Trapezoid nut one or two turns and it will release the z-rods just enough to put and alley key in there...
these parts are described with pictures in the PART 4 of the assembly manual : http://manual.prusa3d.com/Guide/4.+Z-axis+assembly/509?lang=en
Good luck
Re: Layer shifting
You can remove the z-axis-top part (witch fixes the threaded Z-rods and the smooth rods on the frame), them remove the black Trapezoid nut screws and nut... then you unscrew the Trapezoid nut one or two turns and it will release the z-rods just enough to put and alley key in there...
these parts are described with pictures in the PART 4 of the assembly manual : http://manual.prusa3d.com/Guide/4.+Z-axis+assembly/509?lang=en
Good luck
he could, if that's what we're talking about. but it's not. just check if the motor pulley is screwed tight and on the flat part of the shaft if any.
Re: Layer shifting
I'm having exactly the same issue, will also check the pulley advised thanks
Re: Layer shifting
Boy, it probably would've saved me a couple of days if I had actually, y'know, read what you all were posting. Neolker mentioned the 623h bearing, so I got fixated on that and completely missed phrases like "set screw" and "motor shaft," thinking that "pulley" and "bearing" were referring to the same part.
Yes, in fact, I hadn't tightened the set screws sufficiently. I put them in with a little bit of thread lock, and now have two perfect prints. Thanks, all!