18mm Upgrade Brass Z Axis Coupler Oldham Coupling T8 Lead Screw Hotbed Reduced Oscillation Improve Printing Quality for Creality Ender 3 Pro V2 CR-10 S4 S5 CR-10S Pro Z axis 8mm Lead Screw Hotbed…

I ordered a pair of these for a dual Z-axis upgrade on an old project Ender 3. The machining is tight and accurate in the "sweet spot" but only binds at the most extreme edges when you're pulling the pieces apart. There was a little bit of a gritty feel in just one of them - the other was smooth as silk. For the gritty one, I used some polishing compound paste and just worked it back and forth for about 10 minutes by hand, then cleaned it off and re-checked it. PERFECT! I put a little bit of PTFE lithium grease into the joints - all that will fit is the barest film, because the machining is that tight. Seriously, a BB-sized bit of grease was enough for both. I used my bare finger to apply it, but in retrospect, just brushing the mating surfaces with a greased Q-Tip would have been enough and less messy. The upshot of it all is, they work brilliantly to remove lateral wobble from the Z-axis screws while providing positive lift with zero slop. Rolling my Z-motor screws on a flat surface didn't show any indication of bent rods, but you can see them wobble standing directly over the screws and looking down as the tool beam is being raised or lowered. Also, I removed my screw top bearings so the screws can wobble freely as needed, since these fittings can work without being additionally subjected to any frame distortion by binding at the top ends of the screws. The result is Z-banding has been virtually eliminated from my prints!

This product was a good value and the tolerance was perfect. No binding. As described! Thank you!

Missing screws, used short time and showing wear and play

Update, received a replacement from Amazon, it's worse than the first!There's tool chatter and burrs that are causing binding. This is going back.

Great quality!