Simple Anti Z Wobble for Anet A8

by sicksubie Feb 19, 2017
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Installing a second bearing is a typical beginner's mistake.

There is an important reason why all manufacturers do not install a bearing at the upper end of the lead screw. They don't do this to save costs.

The upper bracket should only guide the guide shaft. The hole for the lead screw is extra larger so that the lead screw can move freely.
If the lead screw hits the hole, it is not properly aligned or it is crooked.
In this case the cause must be remedied.
This means either replacing the lead screw or aligning it exactly. In the worst case, you have to do both.

If you force the lead screw into a second bearing, you create constraint. This generates horizontal forces on the guide shaft and not only causes higher wear, but also the dreaded z-wobble.

This is what an aligned lead screw looks like:

This is a shit, does not work.!!!!!!!!!!!!!!!!!!!!!!!

This improvement can only damage the quality of printing and increase the vobling...

The issue many people do not understand is that the z-axis coupler is a spring and that you need to raise it from the motor and leave a gap between the z screw and the motor shaft. By doing this you will have your z screw raised and it will go into the upper hole, thus not needing any anti-wobble.

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i re did my z axis the way everyone in this comment section said to and i'm back to having the same issue, anybody have any solutions to this. since the "correct" way didnt work?

i have 100% solution slack-wobbling of right-Z-helix.
it is simple.
right side of left-right-carriage-bridge is too light, relatively to left side .
just put cargo-load on right side of bridge.

These are worthless. If the threaded rods are not left loose they can cause Z axis problems.

Agreed. The x gantry is already fully constrained by the precision shafts and linear bearings. The lead screws need to be able to "float" in the x-y plane and find their happy place otherwise there can be binding/overconstraint issues. The free floating lead screws are an important aspect to the overall design.

They are actually less then worthless because there is no benefit while actually introducing potential problems lol

I was just reading all the comments on this and I don't see how this would cause any issues with the rods unless it was a snug fit to the frame. Just a thought but if you print a new bracket that this design could go into with a larger diameter hole and ball bearings should work great as long as the rods are for sure not bent.

If your Z-axis drive rods are introducing wobble this will actually make it worse by constraining the floating end.
They serve no purpose. The people who actually understand the Anet are doing due diligence trying to warn new users. If your Z screws don't reach, you've assembled the couplings wrong.

"The Z Axis threaded rod for the Anet A8 is too short to reach all the way to the frame, resulting in z wobble".

This is so ABSOLUTELY wrong!

Mine is like that

Raise the rods up when screwing it into the coupler...

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Are you a nutjob? You shouldn't be talking to anyone like that. He most likely doesn't know it's intentionally designed like that. This is ridiculously uncalled for.

couldn't have said it better

morons....whoever defends this bullshit needs to get behind the theory of 3D Printers. You immediatly show that you got no clue of 3D Printing if you use this. sorry to break it to you

Though I agree with you, your not getting your point over calling people morons. Maybe tell them why you think this, your argument right now is not better then that of the random politician.

I agree that this is NOT how to fix z wobble. We learned this lesson in 2012 with repraps.

was one of my first prints, and it worked perfect. i dont care what the others say, because those couplers are maskign a misalignment issue themselves)

needed them even more once i installed z dampers (the metal rubber type) because this made the leadscrew not even enter the top hole.

this is so fucking stupid. people like you contribute to bullshit questions on support groups. "i don't understand why i am having this problem" "why does my quality look so shit"

Try removing the 4 screws holding the brass part in place to the X motor mount and rotate it 1/4 of a turn. Repeat as needed until the rod/rods line up with the holes. Worked on my first A8, second one aligned just fine.

Issue is the lead screw it is too short. There was a few mm space between the top of the lead screw and the bottom mount

There's supposed to be space in there so the flex coupling can do it's job. You have assembled it wrong.

it's not too short. you installed your coupler incorrectly. https://3dprint.wiki/reprap/anet/a8/coupler

Thanks a lot for this link.

I keep thinking this "Anti Z wobble" piece is useless. People thinking that it's a good idea just don't understand how the Anet A8 works.

This is the correct way to correct someone, not going bananas like in your earlier posts.

the people who use is just don't know any better. the people who upload this crap need to get shot

Muy útil,mido menos vibraciones en altura.

The only use for this would be for people with OCD, this does not benefit your printer it will add more strain to the motor and more vibration.

Please assemble the Z rod correctly: https://www.youtube.com/watch?v=T9vI6DqAcmo&feature=youtu.be
No need for any "fixes".

for refrence, the couplers are also a "bandaid" for misalignment, they mask a misalignment issue by adding a spring into the coupler.

Thanks for sharing this link. That video is very helpful. I didn't realize I had assembled it wrong. It's now assembled correctly, thanks to that video.

I had the same problem, never understood why the rods were too short until now, I'll make this adjustment later today.

I did build it the wrong way like everybody screams, but my prints are absolute perfect, why do i need to change that = ? Figured instead of rebuild it i prints these just to make sure it fits the frame ? anything really wrong with that. ? ... And yes i know now why it is wrong and how its supposed to be, but i thought never change a running system. What do you guys say, anyone done it the wrong way and changed it after that ? Did you see or feel anything different ?

it IS a golden rule. do not try to fix what is not broken.

Nah, as I like to say, "if it aint broke, tweak it!"

THIS IS WRONG AND SHOULD BE DELETED! Do not print this - you should fix your couplers, rod should be inside the frame without using that anti-wobbler!

DO NOT PRINT THIS. If your z-axis rods are not inside the holes, you've installed them incorrectly. See the YouTube video in the comment below.

bulshit it's normal dont do that lol

Not a need part here is how to fix the problem https://youtu.be/T9vI6DqAcmo

If you think you need these, you didn't assemble it correct. https://3dprint.wiki/reprap/anet/a8/coupler

if you install the rods correctly the are flush with the top of frame

Does this work with Anet A6?

im not sure, i don't know the measurements for an a6 but it looks similar so you could try. if not i can design a new one for you if you'd like

You guys are making a mistake comparing the 4 start trapezoidal screws on the Anets to the cheap threaded rod in the Prusa BOM. These things are dead straight with the little bit of wobble seen is usually caused by some play in the coupler bores. Putting a bushing at the top is not a problem like it would be with never straight threaded rod.

Your Z screws are not supposed to be fixed at both ends. Do a google search and you'll find plenty of info about this. I'd suggest removing these because it can only make your prints worse.

they're not fixed, these just extend them a bit and fill the little gap between the rod and the hole; there's still room to freely spin

Spinning freely isn't the problem. I mean fixed as in stuck in the hole. Like I said, do a google search. If you need these to stabilize your Z threaded rod, you need to tear down your X axis, print a new X belt tensioner that tensions the belt against the X rods instead of against the Z threaded rods like stock, adjust everything, and then reassemble.

Trust me, do a little research, our Z screws are not supposed to be fixed at both ends. One end is free by design, by fixing it to the top, even spinning freely, you are either doing absolutely nothing, or making your prints worse by not allowing the threaded rods to flex on their own. Look at the couplers that attach the threaded rod to the stepper motor shaft. See the cuts? It's to allow the screws to flex a little.

Looks like someone watched one too many videos and decided to get on his horse.

Looks like someone else had nothing important to add to the conversation but couldn't resist being snarky and negative.
Eks is right.
The ends of the rods should have play.

Again a copy of a copy of a copy that repeats over and over an error !
Why don't you guy never search what has been done already and why it is not OK !

the rod is not too short, you need to adjust your coupler. It is only supposed to go in 5mm on the motor and rod side. this will cause more issues than good. it would look like this