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）

Works as should

one bolt came jammed and the head was already cammed out, the second one didnt have the relief cut all the way through so tightening is impossible

Good quality, much better than stock couplings.

Unlike most couplers there is no set screw for locking this into place on the notched portion of the motor shaft. Ive found it very difficult to get a good firm lock to the motor shaft with these. Ive tightened them to the point where I feel like anymore risks stripping the threads.

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.

Factory coupler that came with the 3d printer striped right out of the box. Ridiculous I had to order parts the day I bought it. Luckily this piece fits to spec. And I have a second one just in case.

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 used these on my 3D printer and they work great. Excellent quality

Sort of small

They would not clamp to the stepper motor shafts of my sidewinder X1 no matter how much I tightened the bolts.