spin indexers

Iv'e seen spin indexers on E/bay and in ME and MEW, so are they better than a geared type.

I built on indexer which is a cross between L. Sparey and G Thomas types, but without the indexing plates, I only use the available gears for the two lathes. It works, just doing the maths is the problem.

Now I think a spin indexer with a 36 hole disc uses the vernier holes in the following way, You start with the pin at hole 0 then turn the disc to the next hole which is number 1, and so on, to hole number 9, and continue, by starting back at hole 0 again, turning your blank continuously as you go does this the give you 360 divisions. What happens if you have less holes in the indexing disc, ie, 25.30.40 etc.

Iv'e never seen one in action, only dividing heads, So can some one please explain if I am on the right track.

Also could I suggest to the editors is it possible to do an article, with drawings on how to make one of these, BUT without castings, just out of scrap or what you can buy from a steel merchant , here in OZ shipping costs are horrendous. so a casting is out for me.

Someone must have done this, so it could save some thinking time. Has anyone converted a spin indexer to CNC or division master using a stepper motor? If so can you post photos/drawings

This any good Duncan ?

Not got time for a lot at the moment, gotta shoot out and deliver a machine.