2PCS 8mm to 8mm Aluminium Plum Flexible Shaft Coupling D25 L30 8x8mm Connector Flexible Coupler for 3D Printer CNC Machine and Servo Stepped Motor（8x8mm）

They came fast and are good quality.

Fits nicely on the A8-Plus, I just had to bias them slightly towards the motor to let the carriage descend all the way down.

Only issue i've had it seemed to lose hold once, not sure how but i did see it off. Other than that just fine.

If you disassemble it for any reason, expect it to make clicking and creaking sounds once put into service, which is apparently common with this design. Searching online found that putting some oil or grease in it should help.

So far so good!

Massive improvement over the original couplers.

I purchased the coupler because it looked strong and of good quality. For some reason one of them started to separate the upper part from the lower. Yes, I do have Z-axis wobble but not to an extend that the forces would separate the couple and the lead screw is true. The coupler need extreme force on the clamping screws to stay and hold securely. Not sure if they should be mounted butt on or if there is supposed to be a gap between.As with most components these days, there is little or no instruction, at least not easy to find.

The tolerances on these couplings is too loose, causing them to require excessive force to properly tighten and the holes to not be aligned.

Not much to say, they work well for my purpose. Connecting NEMA23 10mm shaft motors to SFU1610 ball screws.

better than expected

Eine der beiden Kupplungen ist weder konzentrisch, noch parallel, was bei einer 600mm Trapezgewindespindel zu einem fast amüsanten, sicher aber beachtlichen Rundlauffehler geführt hat.Die andere ist mehr oder minder okay, einmessen möchte ich die aber auch nicht. Insgesamt vielleicht für Systeme geeignet, die Genauigkeiten im Millimeterbereich benötigen, nicht aber für irgendeine Art von Präzision.