Oldham Coupling 25mm
Oldham coupling, 25mm outer diameter, aluminium alloy hubs with a Delrin/Teflon floating disc.
Overview
The TOHC-25 is an Oldham coupling, 25mm outer diameter, for connecting two shafts that aren't perfectly aligned - typically a motor shaft to a leadscrew or ballscrew.
An Oldham coupling works through a floating centre disc with a tongue on each face, set at 90 degrees to each other, sliding in matching slots in the two aluminium alloy hubs. That sliding action absorbs small amounts of parallel and angular misalignment between the shafts without transmitting side-loads into the motor bearing, which a rigid coupling would. The disc itself is Delrin/Teflon, a low-friction plastic that lets it slide freely in the slots.
This design is backlash-free by nature - there's no gear mesh or set-screw play to take up, which matters directly for positioning accuracy on a stepper or servo axis. The aluminium hubs keep added rotating mass low, relevant on a stepper motor where extra inertia at the shaft slows acceleration response.
Bore size on each hub is matched to the specific motor and leadscrew shafts being connected - confirm both bore diameters fit before ordering.
For a larger shaft pairing, the TOHC-32, TOHC-43 and TOHC-53 in this range step up in outer diameter.
Supplied by Tiny Controls in India.
Specifications
| Coupling size | 25 mm |
|---|
Questions
My motor and leadscrew shafts aren't perfectly aligned — will this actually cope with that?
Yes, that's exactly its job — the floating centre disc absorbs small parallel and angular misalignment between the shafts, without transmitting side-loads into the motor bearing the way a rigid coupling would.
Will using this add any backlash to my positioning?
No — it's backlash-free by design. There's no gear mesh or set-screw play to take up.
What bore size does it come in?
Bore size is matched to the specific motor and leadscrew shafts being connected — confirm both bore diameters fit before ordering rather than assuming a standard size.
Why aluminum hubs instead of steel?
To keep added rotating mass low — relevant on a stepper motor, where extra inertia at the shaft slows down acceleration response.