Step motor coupling(test with 100kg load)

100kg test video
https://youtu.be/VQsFP2SrEtA

the video explain what can coupling do

some day we get a step motor with gearbox 14mm shaht but we
order error size coupling 12mm, we want test the machine with
100kg load soon,so I draw a coupling,when it printed,colleague say
"is it really work?" ,I say "don't worry I'll show you" , I stand on the
machine,Everone is shock,3D Printer not only toy or model, It's
really work!!

I upload a step file,you can change shaft size by yourself