Not a first print issue ovalised holes in z axis
I've had my printer ages and had many hours of excellent results. However over the last few prints I have noticed that prints are squashed in the z axis direction. Holes are noticeably ovalised and the z height is squashed. So something has changed. I have looked through the forums and help archives but I can't really get my head around this. I calibrated everything when new obviously but I didn't think I would need to re calibrate again. My first layer is a sexy as... well it is very nice and the x and y are spot on dimensionally. I'm wondering if there is binding in the z axis or if this is a slicer issue. I use f360 to design and prusaslicer. I'm using PETG from a company I have used before and the problem is evident with different colours including reels I have printed successfully with. I have run diagnostics and calibrations, all come back ok. Any ideas before I strip the machine down and start again?
Thanks in advance
Aiden
RE: Not a first print issue ovalised holes in z axis
Just going by the picture it looks like the right side of the print is lower than the left.
Could your right side z be binding and missing a step? I would do a z calibration and look closely when the X-axis ends hit the top to see if the left hits first.
Maybe one of the bearings is running dry. When you remove the z-axis tops you can pull out the z-axis rods and have a look at the bearings.
RE: Not a first print issue ovalised holes in z axis
@baklin
Thank you for responding. I took the machine apart, three out of 4 z axis bearings were running very rough and sticking in places. I have ordered Misumi replacements. The rods look ok. The bearings are also not particularly well gripped in the printed housings. I could move them and they were in different positions in the block when I disassembled them. I am going to start again with the z axis and then recalibrate all the axis and the e-steps, make sure everything is as it should be and see where we are