With my warping problems solved (thanks to this community), I still have a problem with the z-axis of my Hephestos2. This began a few weeks ago when my hotend crashed into the printbed (terrible mistake of me). Now all prints are irregular in z-direction. As an example I added a photo of two cube shaped models where the grey one was printed before and the blue one after the crash. I also added a photo of the 3DBenchy. I deassembled and assembled the z-axis several times. but that didn’t solve the problem.
Did you check the tightness of X & Y belts. Looks like problem with the belt tightness. Also looks like more temperature. What filament and temperature?
Looks like a problem in X &Y. Is the hot end still firmly mounted? I would check for looseness in the hot end and/or hot end mount, or the same in the X & Y axis.
Check if the leadscrew and linear rods of the z axis are perfectly straigt
I had the same thing. I changed my z rods and checked all the alignment and now it’s sorted.
Try to screw everything thight. I’ve seen that problem in several hephestos 2 at my previous work place
@Selvakumaran_Ganesan
x and y belts are properly tightened. Filament PLA, temperature 210 (but same result with 220).
@Michael_Scholtz
I’ll change the z rods. Did you also change the white plastic parts attached to the two rods? For me they appear to be the weakest part of the z-axis.
@Luis_Diaz
Did check that last weekend and I noticed some screw had come loose. Didn’t solve the problem but I’ll check again.
@Alan_Thomason
The hotend is firmly mounted and somehow I don’t think it’s the x&y. If I print one layer or just a few layers everything looks great. If something in x&y was wrong I should see artifacts in a single layer or a couple of layers right?
@Eric_Buijs right. After reading the posts regarding the z-rods, I would give that as a more likely cause.
I got one of these to check with.
Using that and a few other tricks I got my run out down to 1 micron
It might be tough to use the dial indicator to check the z-rods. I’m not saying it can’t be done, it just might be difficult. How hard is it to remove the z-rods? If they are removed, you can roll them on a flat surface and see any bends very easily (granite counter top would work).
@Alan_Thomason
De-assembling the z-rods is not too hard. Would rolling be sufficient to check a smaller defect in the rods too?
On a very flat surface, with a light shining from behind, you should be able to detect gaps on the order of 0.001". You could measure the gap with a feeler gauge set from the auto parts store if you feel the need to know an exact number. If you order new rods, you could use this method to assess the new rods and decide if they are actually as straight or better than the originals.
Your Z-axis couplers might have stretched.
@Thomas_Sanladerer
Thanks, never would have guessed that could happen but I’ll change both the threaded rods and the couplers.
@Eric_Buijs you might get away with simply reseating the rods against the motor spindles and slightly pre-tensioning them.
@Thomas_Sanladerer
Thanks but I deassembled/assembled the threaded rods twice without succes. So I’m afraid it’s one of the z-rods or one of the couplers.