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

I should have listened to the other reviewers. Not only was the machining and tolerances pretty far off for a precision job for properly aligning a leadscrew but the small screws are super bad quality (see picture close up of the striped screw head). The 5-8mm holes are pretty far off causing you to need to extra tighten the screws to grab hold of your leadscrew and stepper shaft. After I realized how terrible the bottom screw was (to the stepper shaft) I replaced the top screw with the one that was in the factory coupler and it never stripped. At the very least if you still feel like many of us dont know what we are talking about and you still want to give this a try, replace the screws with the ones that came with your stock coupler. Its a good thing I did that or else I would have lost the stepper and the leadscrew to a wobbly, out of alignment poorly manufactured coupler. I have yet to find a solution other than properly aligning everything with custom designed 3d printed parts and the solid factory coupler. After this failure I have pulled out the calipers to make sure everything was aligned properly and my issues were fixed and I never needed this part anyway. One star for wasting my money and costing me a new stepper motor.

worked as it should and am well pleased

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.

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.

Il prodotto è arrivato da UK, un pò caro e spedizione lenta, ma il prodotto fa molto bene il suo lavoro, acquisti per stampante 3d. Consigliato come upgrade.

Works well on Z-axis lead screw for my Ender 3, and is a definite upgrade to the stock coupler. The finish is decent, and seems pretty solid. My only complaint is that the coupler will come apart fairly easily if you apply any form of tension pulling on the coupler, which can get very annoying if youre used to pulling up on the X-axis gantry to manually raise it. Thats 100% a design shortcoming specific to my application, and not a fault from manufacturing.

Just what I was wanting

Good idea, I hope it works

I like these type of coupler alot better than the set screw type because the set screw type you can never get them exactly on center. with these friction type they stay on center and nothing damages the lead screw