Oldham dovetail coupling (plus thrust bearing)

This Oldham coupling is made with a dovetail profile to constrain the vertical movement. If used with a lead screw, it would be better to install the nut with some springs to free the tilting movement of the screw.

This is originally made for my QIDI X-Plus.

Shaft diameter: 5mm
External diameter: 22mm
Coupling height: 24/25mm (depends on version)

Thrust bearings

You can print one flange to fit a bearing. I used a BA9 bearing but you can use a simple 608 and use it as a thrust bearing by printing its flange and housing. With QIDI printers you will need also the Nema17 spacer for the motor and M3 set screws.
Otherwise, just print 2 standard flanges.

Suggestions

• Use a low friction material for the intermediate disc (I used Igus Iglidur, PA should be ok).
• The parts are designed with just a little clearance, I used a file and sandpaper in post to refine the fit, the parts must moove freely but without backlash.

Print settings

• 0.15 layer height
• Supports: yes (2 layers of z offset)

Version history

• 2023/03/17 - First public release