2-Pack CR10 Z axis T8 Anti Backlash Spring Loaded Nut Elimination Gap Brass Nuts for Upgrade Ender 3 Ender 3s Ender 3 Pro V2 CR-10 Tornado 3D Printer 8mm Acme Threaded Rod (Nuts)

The bolt holes do not line up.

I got these to install on my Ender 3 S1 Pro and one of the two that came were too big. It also seemed to be much poorer quality than the correct size, so perhaps a counterfeit? Notice the burr or machining defect stick out in the picture? The smaller, correct sized coupler didnt have that defect. Overall not a great first impression, but Im going to return one and see what I get back from the seller

The long dovetail section has a little looser of a fit, and there is a tiny amount of backlash in these. Cant tell how much. The more important issue is the nut hole on the Ender 3 mounting plate is not aligned on the x -axis (with my linear rail setup). Im getting the mounting holes slots and will open thhe nut hole for more clearance. Will update review if I need to use

Quality was ok but caused z-axis binding. Nice idea, but the experiment does not work.

I was (am) having issues with my X gantry falling down between prints and thought this may be the fix. It still falls though, so IDK what to try now. Its a very annoying issue though. :/

This is an awesome solution to keep any inaccuracies in you z lead screw from ruining your prints. Polisi3D always has some of the finest machined parts, better most times than the BIG brands. Fit perfectly on my Ender3 and as I said the machining is so good it glides. A work of art for a oldham coupling. Will be buying more for sure.

I bought these along with a Dual Z Axis Upgrade kit for my Ender 3 V2. They can be very hard to finally get threaded on the rods. Once I got them installed, calibrated and made sure everything was level I turned my printer on. I went to full height and them bottom. There was some pretty bad grinding. I did some more adjustments and started a 1h15m print. 40 minutes in, print got ruined. I did the same print 3 more times with the same issue in the same spot. I again adjusted and tried again. Again grinding and ruined print. I thought maybe it was the Dual Z Axis Upgrade kit. I decided the easiest route was to just put back on the stock ones. So I removed the anti backlash nuts and tried the same print. It went perfectly on the 1st time. With these anti backlash nuts installed the carriage is very hard to move and you dont want that while 3D printing. You want smooth motion everywhere. I suppose this may be good if you only have a single Z Axis lead screw. With Dual lead screws these are unnecessary. Ill be returning them.

I bought these for my Ender 3 Pro nut, installed it on the original left side...and the inner diameter is too small for the Pros 8mm lead screw. The ad and packaging both say this set is designed for Ender 3 Pros 8mm lead screw. This will also not fit the Ender 3 V2, which I also checked out. Poor QC? Improperly labeled package? Returned and now looking for another vendor to do it right.

Easy to install. Just do one side at a time.

Very affordable and easy to install. I have a build plate thats not very flat, so I have mesh levelling constantly moving my Z up and down in very minute amounts. I figured a set of these would help and they really do seem to.