A double cardan type connector for coping with motor misalignment in CNC machines and 3D printers.

After one of my aluminium couplings failed on my CNC machine, I designed a new coupling that could cope with angular misalignment as well as motor offset.

I made my version from steel, but this should be able to be printed. Its designed to fit onto 8mm shafts- by all means tweak to suit your projects

To build you'll need the following
1x UJ_Centre_8mm
2x UJ_End_8mm
2x UJ_Block_8mm

You'll also need:
4x M6x25 CSK machine screws
2x M4x10 Sock Head Cap Screws

Just a few very simple points to note during the assembly.

1. The blocks should be tapped out to M6. The coincident holes in the centre and end pieces should be 6mm i.e. not threaded.

2. The counter bored side of the hole in the ends will need opening out to 4mm otherwise it wont clamp onto the shaft

To assemble, just put all of the bits together. Make sure that everything fits and moves as it should- you may need to file a clearance depending on how misaligned the axis/ motor is.

Modify as you need and share away.

That's it. Enjoy.