Befenybay 2PCS 5mm to 8mm Aluminium Plum Flexible Shaft Coupling D20 L25 Connector Flexible Coupler for 3D Printer CNC Machine and Servo Stepped Motor（5x8mm）

For some reason the flexible couplers milled from a single piece of aluminum tend to shear on my DIY CNC machine on both the X and Y axis. Ive tried different brands and suppliers, including the one in the photo, with the very same results. Within 6 hours of run time it breaks on the simplest of carves, ruining my workpiece. As you can see in the photo and the pictured break, one has to question the mill stock used vs. who mills these from that stock. However, since changing to this 3 piece design, Ive been running fine without any issues or mid-carve failures!!! Thanks!

I tried the other type of couplers that look more like a spring on the Z axis lead screws on my Ender 5 Plus but they stretched out and messed everything up. Got rid of those and replaced them with these. These work great and support the weight of the bed with ease. They are not really flexible so these will not solve any Z banding issues but they do stay together and don’t expand like the other type did. They don’t get 5 stars from me because of lack of flexibility but they are decent enough to get 4 stars.

Took me some time to figure out what was causing the banding on my print. When I took the lead screw out and looked at the shaft coupler while it spun, you can easily see the top piece wobble, thought it was just a bad z-screw initially, but after replacing that first, it had to be the coupler.

Les flexi-coupleurs de ma LeadCNC, monobloc en aluminium casse régulièrement suites aux contraintes elevées en decoupe de bois dur. Ceux la ont lair plus solides, bien quavec un leger backlash qui nest pas geneant pour mon utilisation.

After a few uses the coupler was stripped and kept coming off the z motor.

Holes out of alignment. They wobble. The hole for the motor is skewed enough to be visible. Probably done free hand on cheap drill press. I payed alot for quality got junk. Shame.

5mm was small. Had to drill it out a little bit.

All good as expected

They seem to work. Hard to test it. You have to take the Z rods out all the way to get it to go in. But thats a good time to clean them. The fitting is very loose at first and the screws are very hard to turn. I thought I was going to strip it. Then finally it turned and tightened. I thought I had the wrong size at first.

These are most probably planned to separate, so these do not work for my use case: couplers for cartesian 3D printer z axis leadscrew. When moving z-axis, either one of these will separate. The grip is good, too good. Now I wasted two stepper motors because I cannot get these off without bending the axis.