V-minion z-wobble or banding
Hi all, I built a v-minion full kit from ratrig, everything was ok but when I tested it I found some z-wobble/banding, artifacts in Z axe (in my opinion). After that I try a lot of things, I try to give my best aligning the leadscrew with the pom nut and motor but the problem was still there, I replaced everything, the leadscrew, the coupler (spider and other types), even the stepper motor and the linear rail. I changed the pillow block printed part for another one...
The last thing I'm thinking about is about a skew error, something that is not 100% squared in the main frame, so I'm thinking about re-done everything again, even print all parts again.
In the other hand I have some mods that I've found here and around. Like double linear rail in Z with a new printed part instead of the one that I have that is metallic. I also saw a mod with a motor with leadscrew integrated like voron or prusa. I also see one that is using an oldham coupler instead of the pom t-nut.
Could you help me with this problem? thanks a lot.
PD: Attached the evolution of several changes and improvements.
99 Replies
The last prints that I tried to test it. I tried with different layer height and the pattern is always the same
Hello. Have you been able to gain some progress here? Cause I have absolutely same issue.
Hi, I din't have enough time to improve it but I'm rebuilding the machine entirely, with new printed parts in ASA, when I rebuild it completely I will share the status of the problem... If it is still there I would try with some mod for Z axis, like oldham, wobblex, betled Z or dual linear rail... let's see
inland-turquoise•11mo ago
Hi, I've fixed it. Centering the Z-screw rod solved wobble
Yes, I've tried that a lot of times, and give my best trying to find the perfect alignment but it didn't work
And have you been able to reassemble the machine already? I am thinking about it during this weekend.
I'm trying to do it during this week, I hope to finish it this weekend as well. I already have all the printed parts in ASA ready to be used in the new build.
I also have a oldham coupler and wobbleX 8mm here if they are necessary using a mod. Let's see
I have Oldham already fitted but it have no effect. With or without it's still there.
Good to know... dissapointing but good to know 😅 . have you installed this mod? https://www.printables.com/model/465831-ratrig-v-minion-z-decoupler-resolves-z-banding-z-w
Printables.com
RatRig V-Minion Z decoupler (resolves Z Banding / Z Wobble) by Brun...
Adopted to use RatRig Z decoupler to resolve Z wobble | Download free 3D printable STL models
Yes, that's exact mod i used. I doublechecked the distance extension of 17mm with model too. Tried to print my own motor holder and pillow. No change. Sliding Oldham left to right does not help too. Fooling around with x gantry angle to frame eather. I have three leadscrews, bunch of couplers and secondary motor. I am just missing something.
I also tried to refix the linear guides, running around the machine with caliper. I think there will be something ridiculously obvious I am missing. 😂😭
It sounds familiar to me 🥲 Good luck !! I hope I can start work with it today...
Hello my friend. Have you resolved it yet? I think I found it on my side.
At first i got rid just the Y axis waves by realigning the frame. i bouth at the hobbystore calibrated 90° angle and found that vertical profile was not properly aligned with the horizontal. I aligned it and after that i tried to align the decoupler on X gantry left and right by puting out bimetal decoupler and just screwd to the chasis the lead screw nut so it was rigid. by that i was able to get stright line from top to bottom and motor.
with that in mind i started to fool around with the calibrated angle around the Z motor and figured out (i still dont understand why) that z motor holder - printed part is not in 90° with the linear rails. so i ended up with putting 0,3mm shim bellow low screw on that and by that get proper 90°angle. and again with calipers measure axact distance of the leadscrew to linear rail.
i will try to put some pictures together. its worth of a million words 😄
harsh-harlequin•11mo ago
I also have the Oldham mod on my Minion and suddenly had a strong Z-wobble. I then removed the ball bearing at the top and the problem went away immediately
i am having good results even with the bearing. but the sound of it sometimes is superanoying. 😄 i think i will remove it.