Z axis is not firm, can be lifted slightly, cnc4newbies z axis

So I can’t seem to catch a break! After firming up the machine and getting it connected to my dust collector I discovered I can “shift” the Dewalt mount up on the z by about a mm or two. The shift seems to be in the area behind the mount plate, possibly the connection where the plate meets the fast screw nut? The screw itself and the coupler are tight and show no give at all but the bearings do lift. Has anyone experienced this with the cnc4newbies slider (3 inch wide model)?

Nope haven’t had it bottom out and I’ve had it do some cuts since and I’m sure it’s affecting my z accuracy. Like I said the coupler and screw seem tight. Coupler has loctite along with the rest of the machine and if a screw did fall out wouldn’t that only affect DOC? I’m literally able to grab the plate on the z slider where the mount is and pull up and have the bearings shift upwards along with the plate while the rest remains in place. I remember reading a post somewhere about someone’s z dropping on him due to the sliders screws coming lose but I’m not sure if that’s the exact case here.
Edit: and just to be clear the quick turn screw shows zero movement when I do this.

Fair enough, I snapped this one real quick. Will have to wait until the kiddo goes to bed before I can do a video.

So I can just lift from here and shift the mounting plate up by about a mm or two. The dewalt mount is also firm, just in case anyone wonders if it’s rocking, it’s the whole z mount shifting up slightly.

Backlash in the screw nut?

That was my thought, bummer. I was hoping there was a way to tighten it in the event that it was a lose connection between the screw nut and the back of the mount plate.

I have the same problem on my cnc4newbies slider. I emailed cnc4newbies but I have not got a response. I removed the router and the sliding faceplate. The anti-backlash nut has some play between the brass sleeve and the actual nut. There seemed to be a spring in the mechanism. The anti backlash anti-backlash assembly is held in place by 2 cap screws that had cut clear thru the plastic I loosened the screws turned the plastic collar to a different location put some blue locktite on them and tightened them down. There is less play now but still a little. Is that how it is supposed to be?

I’ve been in communication with cnc4newbies and after stripping it down to the lock nut/backlash screw amd showing them the slight play is indeed with that part they stated that its normal. I dont remember the Inventables one having it? Anyone else confirm minor play is normal?

I have a slider from an other seller, it have an anti-baclash nut with a spring and it have a small play.
The spring do the job and it not affect my cut, the weight of my spindle and the spring remove all the play. Mine have ±0.030" when i push on it and the spring return the carriage at the original place.


Here is a reply from Joe at cnc4newbies:
Remove the spindle mount, check the 4 flat heads screws if they are tight. If they are tight, remove them to have acces to the 2 screws who hold the nut, remove them and turn the nut few degrees and re-tighten them. The problem should be solve!!

Important thing to know is they are anti-backlash nut, not zero back-lash nut like a ball-screws, it mean a little play will be always present, the spring in the nut is for removing this play. With the gravity and this sprig, it should not affect your cut.

Hope this help!

Also If you google anti-backlash nut you will see how they are constructed.
Mine works fine now.

If your are the guy from 3d Motion, your Z axis are not better. my friend have one from you and it’s totally crap!! Sorry if I’m rude but it’s the truth!!

You are Mark T. from 3d motion!! Stop “trolling” here!!

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