Lathe and concave/bal lturning

[irving2008]

Then, depending on the radius, you need a form tool, tho a 60deg threading tool to make a v-shaped pulley would do a perfectly good job...

[GeorgeD]

Hi Irving.

Already made a v-wedge pully for a motorI had,will get some batteries for camera tomorrow and post a pic.

Its as you first said half the radius of a given diameter is what I'm trying to achieve so that the pully sits on the rail like a glove fit.

[irving2008]

Hi Irving.

Already made a v-wedge pully for a motorI had,will get some batteries for camera tomorrow and post a pic.

Its as you first said half the radius of a given diameter is what I'm trying to achieve so that the pully sits on the rail like a glove fit.

Which unless perfect will either increase friction significantly or will be sloppy in the transverse. A v-shape is easier to achieve, provides a point contact which is the lowest friction, and is self-centering.