5mm to 8mm Flexible Shaft Coupling Rigid Stepper Motor Wheel Coupler Connector Aluminum Casing with Screw +Hexagon Wrench(Pack of 5)

Nice pieces and worked as designed. What more can I say?

Seems like a solid product. Havent put it to use but its exactly like the description states. Very nice blue color and sturdy. 5 pieces

Works well for my mini cnc.My set was missing one screw and I never received a response from the seller about that, so I'm pretty disappointed in that regard. Fortunately I only need a partial set.

These are absolutely perfect! I'm using them on those standard small stepper motors and connecting them to some lead screw rods to control some mechanical parts and they have held tight even through some pretty high stress situations. Very impressed with how well these work and I'll be ordering more just as soon as I need them :)

Well made, but the set screws slipped off a few times. I'd give it 5 stars if the screws had some loctite (or similar) on it from the factory. Apparently some oil drained down the lead screw (which is going to happen!) and loosened the set screws, which then came loose. Anyway, being a petrol head too I have a bunch of Loctite Blue ( such as http://a.co/db5wfxL ) sitting around, so product works fine now.

I redid my bearings as IGUS Drylin bearings, which have a little more resistance than standard steel linear bearings. Enough to cause undesireable backlash when using couplers that have that spiral cut in them. These removed the backlash and make the prints much more accurate.

Good quality.

I have a tevo tarantula with a carbon fiber kit, linear rails, dual z motors individually controlled by the board, toothed idlers, glass bed, marlin firmware, and tensionsers on both belts. calibration cubes were printing very good. I gave this a shot out of pure curiosity since it was cheap and my frame is fairly plumb and square, so I figured why have a flex coupler? this added almost a perfect z wobble pattern to my cube, despite measuring and leveling everything after install. immediately went back to the flex, printed a cali cube, and it was gone. if you're hoping to solve z banding, this will likely cause more. if you're hoping for more stability in the connection, it will likely add banding you didn't have. steer clear for i3 prusa type 3d printers.