This is a Spindlestop for a Lathe with 26mm Spindlebore.
Extend it with M8 threaded Rod to the length thats needed. I added a 300mm Rod. For stabilisation you can screw one of the stops with M8 thread somewhere in the middle of the allthread.
I have used 2 x O-Rings 20 x 3 mm to hold the parts in place.
I got the idea from this Aloris Spindlestop.
Update 10.08.2023:
Thanks to @Cofferoast an error could be corrected (inner thread of the mainbody).
Exchanged the Mainbody.stl and Mainbody.gcode.
Also uploaded updated CAD drawing - now Spindlestop v13.
The author marked this model as their own original creation.