ACME Rod Rubbing on Spindle Mount - Any Fixes?

I took apart my machine to do three stiffening mods (X, Y, and Z) and after I put it back together, my Z-axis keeps binding. It is not the V-wheels or the eccentric nut - I’ve tried and retried each of those at various tensions. What I have realized is that when I tighten the spindle mount onto the Delrin nut, this makes the ACME rod tilt, and now it’s rubbing on the bottom back of the spindle mount. I moved the Z-axis through Easel and pushed lightly on the bottom end of the ACME rod while it was moving and the grinding noise was gone and things moved easily.

Anyone else have this problem or have a fix? What I noticed was that the Delrin nut hangs in front of the z-makerslide with a gap (which is should) but by having that gap, when I tighten the spindle mount onto the nut, it pushes the nut back into that gap creating the tilt you see in the photos.

Perhaps I need to reverse my Z-axis stiffening mod (I did it since I was doing the X and Y so I figured “why not?”) and revert to the nuts/spacers as shipped, but I thought I would throw this question out there first.

Don’t think I haven’t considered that! Where did you get yours?

It looks like maybe too many washers. Acme doesn’t look plumb.

have you checked to see if the acme rod is bent?

I know alot of people have been having issues with them being bent

Mine was bent on my machine but I called inventables and they replaced it right away

If the cause fo this problem can’t be found, then one fix would be to fit a mount/bearing to the bottom of the ACME screw.

Available here

Have you checked the bots holding in the bearing at the top of your acme screw. Belt looks like it may be a bit tight and pulling the acme out of alignment.

Make sure your washer/nut stack up is .375 inches. If you want the prescribed part, it’s item 25312-15.

Its maybe the camera angle but it looks like the shaft is not parallel… look at the third photo

the shaft is further forward at the bottom than the top,

How to fix it? remove or add washers

Is this the bearing you used? Flanged Bearing. Does the ACME screw just sit on top of it?

Yes, that’s the bearing I used.
The bottom of the ACME screw is turned down to 8mm to fit the bearing.
I’m not sure if the standard X-Carve ACME rod is turned the same way, I got my rod from 3dTek along with the bearing - and all the other parts I needed for the X-Carve.

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