I'm looking at using Centroid's Acorn on my conversion of a Smithy Midas 1220 XL and need some ideas about spindle encoders for the lathe portion. The spindle is driven by step-pulley(v-belt) so mounting a standard shaft optical encoder would be impossible without major Mods. Right now I've come up with an idea, but I was hoping someone might have another solution that may work easier(or more affordable). RLS makes off-axis magnetic encoders like this one, https://www.rls.si/eng/products/rota...encoder-system, which have ring magnets that I could mount on the exterior of the pulley and build a bracket to hold the read head.
I did do quite a bit of searching thru other build threads, but it looks like all the other Acorn lathe builds are using timing pulleys or gears mounted on the spindle to drive a standard shaft encoder.
The other idea I had, which seems like a less-than-optimal one, would be to use an encoder with a friction wheel(rubber rimmed wheel) that would sit against the spindle pulley and would be driven by... you guessed it, friction!!! Unless I'm mistaken the friction wheel would have to be the same diameter as the pitch diameter of the spindle pulley, so that it's a 1:1 ratio. Is that correct? If that's the case, it probably wouldn't work for me as I dont think I could fit it inside the gearbox as is.
Any ideas?
Erik