How To : motor to ax coupling
When a stepper motor is inline with a screw thread ax then you can use a fixed coupling. But in practice it difficult to make this inline. So we need  flexible couplings.

1) Some people are using a Tube. I have no experience with this coupling type, but i think it’s not accurate enough to use it on an engraving machine.


This picture is from

This one is used on a foam cutter. I think that is ok because there is no or a little force needed for foam cutting.

2) A very smart coupling is made by Jaak Claesen ( see also on my “visitor experience page” )


It’s easy to make and you can replace the plastic part through a thin metal plate. About 0.1mm thickness.

3) Aluminum and nylon. The are easy to make and works good.


Nylon can absorb fluid and that’s nice. So heat up some thin oil and put the nylon in the oil. Than you have a self greasing coupling.

You can also buy this oiled nylon. ( I don’t know where but it is on the market )