8mm to 12mm Rigid Clamp-On Couplings, Aluminum Shaft Coupling 32 Diameter 45 Length, Motor Shaft Coupler Connector for CNC Machine 3D Printer DIY Encoder

Fits perfect as described

They are a little snug on the 8mm side, but nothing that would cause any issue with assembly. I'm very glad that I was able to find this style as I do not like the spring style connectors.

The media could not be loaded.  I used this to attach my motor to my drive wheel (from a stroller) for my Halloween flying ghost display. Works perfect.

I purchased this NEMA 23 motor mount here on Amazon https://www.amazon.com/gp/product/B09QRZ13J5/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 and was trying to find a coupling that would work. The first one I ordered, which was a different brand had screw heads that protruded so much that the coupling would not turn in the motor mount.THIS Sinoblu motor mount worked great! The heads are much lower profile allowing the coupling to turn in the motor mount. If you are using a heavy duty motor mount, get the Sinoblu.

Por descuido rompí varios acopladores flexibles, ya que los Motores a paso que estoy utilizando son Nema 23 y cuando éstos ya se encuentra instalados pueden tener un gran torque, es por eso que me decidí en cambiar de acopladores flexibles a rígidos, compré solo uno para probar la calidad del mismo y en verdad son excelentes. Cambiaré los acopladores para los otros dos ejes, ya que la calidad del material y la construcción del mismo es fantástico. Lo recomiendo 100 %