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
genetic-orange•15mo 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 😄
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.
It sounds very familiar to me XD, I mean, I tried to do all those checks in my side but nothing worked. I'm rebuilding it right now, I'm with EVA 3.0.2 right now, but the rest of the structure is ready. I also printed my own parts in ASA (3DO ratrig color). Let's see if something is better in my side... Thanks for your time to respond here, for sure, If I'm still having problems I will do everything you suggested. Thanks very much.
It's looks very well, maybe the ball bearing on the top was to tight or it does not moving properly?
Not sure but now everything is fine without it 😊
I'm very happy to hear this, I hope to have the same results XD
I hope it too let us know
Having this issue aswell 😐tried printing some aligners and now doing a test print.
And what from the above statements from me or @migferlab or @proof84 you already tested?
I have tried printing the alignment tools for the leadscrew, and i have swapped out the crappy coupler that comes with the kit to a solid one.
I wanna try the Z decoupler mod but i cant print anything other than PLA myself yet.
This is with the bottom of the coupler sitting flat, it is crooked.
frozen-sapphire•14mo ago
Hi there z wobble people, I am here to join the club.
Waiting on a new leadscrew atm.
I also have:
-re-squared the frame
-re-tensioned the belts
-switched to a solid coupler
-played around with alignment
Z-wobble is still present....
However, could any of you measure a calibration cube to see if there is a difference between X and Y side?
Because that's my main issue, got different dimensions, really annoying.
How different dimensions?
frozen-sapphire•14mo ago
Measuring a cube (or hexagon or cylinder or whatever) 30x30x30mm X direction is ~0.15mm shorter than the Y direction.
I dont think its relative to the z-wobble. rather then stepper config or something like that. z obble will give you waves in leadscrew lenght (4mm).
and if its shorter maybe you are loosing steps.
frozen-sapphire•14mo ago
I do have Z wobble and the lines at roughly 4mm intervals, it was actually you who suggested that my inaccuracy problem could be because the lead screw skews the prints.
But I am not sure if there might be something else to it that's why I asked if any of you could check your dimensions, so I can see if it is z wobble related or not.
i did not printed calibration cube, but from samples around here i have deviation about 0,02mm X to Y. if that helps 😉
just thinking about it again, and it could have effect. if the leadscrew is that bad that it travels 0,15mm in the layers. if you could measure dimensions in lets say 0, 2 and 4mm in height (z axis) it will give you idea. like for example if its -0,15mm at begining of wave (0mm), then 0mm in middle of wave (2mm) and +0,15mm at the end of the wave (4mm).
nevermind. i was just thinking out loud. it will be the same. because each side will be moved. hmm, but that it could have effect still applies. 😄
did you tried to measure thickness of the wall?
eastern-cyan•14mo ago
I've solved my z wobble but I had to compromise z height. Replaced my lead screw with an ldo branded lead screw from filastruder. They did not have 250mm length but only 230mm. Then I had to tighten the antibacklash screw to make it a little more snug and so far it has fixed it.
I've just rebuild my printer, with new printed parts, it's in stock version yet... and the z-wobble is still there, I don't know if I am a little bit clumsy aligning the screw and everything or if i don't know how antibacklash works or what happens. I will try to give my best with this but I think I'm going to test some mods or even a motor with a leadscrew.
Well, after some adjustment this morning I've printed other test and it's almost gone, the best result I've got so far. Even if I use a light on top of the cilinder that I'm printing the pattern is very difficult to be appreciated
good to hear.
But it's too weird because to me eyes the leadscrew looks like it's not 100% perpendicular XD
I will try to do more tests
well i see small possition changes at top too but the z-wobble is not there. the issue will be in the general position of the center of the z motor to center of the z nut and overall skew of the alu profiles 😉
thats what i got as impression out of it.
Yes, I agree. With this Z design it's easy to introduce a little deviation, even if the z nut anti-backlash is not properly aligned in X/Y axes the leadscrew can be misaligned, also the screw in the anti-backlash nut to apply some tension. The coupler should be totally horizontal as well. And the overall skew as you said, for sure.
I am not sure if this has been subject of discussion here but left - before and right - with wobbleX
Before, the leadscrew was pretty much as parallel as possible...
looks very well, I have a wobbleX 8 here, what mod have you installed?
Maybe this one? https://www.printables.com/model/518585-wobblex-ws8-coupling
Printables.com
WobbleX WS8 Coupling by Ivah Sukhikh | Download free STL model | Pr...
This is a coupler for the Z axis based on WobbleX for an 8mm screw. | Download free 3D printable STL models
That's incorrect usage.
I have my own mod, I'll upload it to printables when I get to it...
https://www.printables.com/model/675516-v-minion-wobblex-adapter
Here. But You will need TR8x4 POM nut and also most likely to reprint extrusion cap
Printables.com
V-Minion - WobbleX adapter by Ferfi | Download free STL model | Pri...
Simple piece to adapt minion to WobbleX | Download free 3D printable STL models
Im just gonna do belted Z 😬
You can't go wrong with belted. But it is more work and iirc more expensive and more printing as well. But the result is guaranteed.
Im getting the parts printed in PC-CF so it will already be kinda expensive, the PETG are really bad.
The most annoying part is extracting all the files from the .step files to get them to .stl 😂
I think I have a TR8x4 POM nut somewhere... I will take a look
Is wobble x still only from aliexpress?
Yes. Or you could source the magnets and needle rollers (most likely from AE as well) and print the middle piece as well.
That kinda makes it a poor solution :/ wait a month for a tiny little device.
I mean... Belted is the same case. You'll have to source at least the 288mm(?) belt most likely from Ali as well
Ali is usually two weeks to Europe for me
eastern-cyan•13mo ago
controler fan speed
That is true but its a more major overhaul so it is more justified imho, Wobble X you should be able to just order from Amazon as a quick fix.
I will install it, the 3060 top end cap with a bearing... the bearing should be fixed to the part? I mean, it is tight in the bearing place or not?
I had to press it in using pliers, hands were not enough. Best way might be to cut it so you print only the region with diameter and see for yourself... Depends on material, seam quality, flow multiplier calibration etc.
Thanks, I only want to know if it is designed to fit tight or not, because the part that I printed is not tight at all If I flip the part the bearing falls
It was tight for me...
I'd dab a drop of glue there to make sure in that case
I've installed the mod and everything looks great for the moment
Send some pictures.
Well.. Is it possible I have shorter cable holder? 😀
The filament used to test it was a gift from a store in the last printer party here in Spain. I didn’t calibrate it properly, I was using another pla profile.
The black piece for the sleeved cables do you mean? Yes it should be easy to modify
If it fits then it is fine but from the photos it looks like an uncomfortable clearance
Yes, you’re right I remember that I had to move to the right the support, the x endcap
I will find a short one or I will modify the original one
"modify" as in hot knife machining 😀
looks good. so if you could summarize, what you had to do apart of that mod? i have oldham decoupler which is prety good too, but you end with 17mm extended leadscrew from its original position, which i dont like. and only other option is belted. 😄
well, there is other mod for oldham decoupler, it changes more parts than wobbleX mod, you have to print the motor cage, and more parts. Is 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
I printed the wobbleX mod from Ferfi, the link is some messages above, and I only had to change the anti backslash nut for the wobbleX and t8x4 screw nut and the top endcap with the bearing
And the leadscrew has to be "rised" a few millimeters to reach the top bearing
And you have to align properly the entire Z elements
Not much more to be honest
I think you got me wrong. That Oldham decoupler mod I have on my minion for weeks already, but I am asking if you could say what you had to do with the wobble. Like what all the changes you had to make to get wobble in place and working.
I don't like Oldham because it's 17mm offset. It's working great bud I like things tidy so iam fooling around with thought with wobble or even belted mod.
I’ve installed the Ferfi’s mod
Calibrate and use quality filament and do another test to show 👌
Just an update - the wobbleX is not the wunderwaffe I hoped for...
Ill disassemble and clean the screw today, hopefully it will help...
The ripples appeared after about 10-20 hours of printing...
Did you tried different filament? I found some unprintable. Like spectrum white came totally wet. Polymaker white doesn't make out with my speeds and nebula is quite ok. Spectrum in colors are great, nebula too but devildesign is my best choice since they are porforming great whatever I want from them.
Iam testing now filament pm as its local manufacturer and it was making official filaments for prusa before prusa built its own filament factory.
But white is always the worst. I like it much too, but it's realy hard to get one which is working good.
I have Oldham mod and it's not as good as I thought too. It will give you some room to play but main thing is to realy align leadscrew to rail. Y axis on the z motor. X axis on the wobblex/Oldham and to make whole frame from profales square or exact 90deg.
What helped me most is aligning the frame with calibrated angle, then align x gantry with cans and then fool around with the Oldham and z motor.
I still have little wobbling on my screw, but doest apply to the print. 😉
one better photo, hopefully it is more noticeable.
hopefully it is just a problem with screw aligment.
Yes it is.
Interesting....
All pins are completely rusted
Wtf?
I guess lube them while you can lol
For sure going beltes after seeing this 😔
Well, I don't see such an issue with Oldham mod. 😉
I've dried this mod, and so far no z wobble
The only thing now is the spider couple can't detach if the nozzle touches the bed to prevent breaking the bed/nozzle
The Z axis detaches at the wobbleX, so you will still not crash into bed
Yea it worked. I have stainless pins on the way.
Normally with just the spider coupler the lead screw would go up after nozzle hitting bed. But with z wobble mos there is a F688ZZ Ball Bearing that won't let it go up
1. Place a finger on the nozzle
2. Pull up with moderate force
X axis is not rigidly constrained to z axis, it is held only by gravity
Don't turn on the heater if you will use fingers on nozzle. 😂😂😂
@ferfi4004 I am talking about this mod: https://discord.com/channels/582187371529764864/1153699551652352150/1187488610031771800
Don't think I can pull it up
(optional) 😄
Yes that's Oldham mod I have and it's just about what type of coupler you have.
The bearing up there is not so rigid that it will stuck there. And I am not using the bearing there anyways. But I also don't use spider coupler. 😂
With wobblex you have detaching place at the wobble so it's little bit more safe.
What coupler is that?
this type. i have it from our czech supplier but its the same. https://www.amazon.de/-/en/SUOFEILAIMU-MI-Coupler-Coupling-Flexible-Diameter/dp/B095K2J8RM
SUOFEILAIMU-MI Coupler 1 Piece 5 x 8 mm for CNC Engine Jaw Shaft Co...
For CNC engine. Elastic coupling. OD 19x25mm. 3/4/5/6 / 6.35/7/8 / 10 mm. Package includes: 1 x coupling
two screws for each joint
Thx
But it looks like it won't separate if nozzle touches bed
No it does not. Well unless you will use just one screw out of those two for motor side. But i don't think it's that much needed. In this case I like the wobblex version because it will detach there.
Sorry, I'm very very late on my response. I've used the printer a few times, not too much, but everything works fine now, well not perfect for sure because I didn't expend so much time in calibrations... but much much better than before.
This has to be some sort of a record for a thread to be marked as "resolved" after literally half a year lol