The Seig mini lathes have a two speed gear box in the head. No counter shaft or belts to mess with. The lowest speed on my old mini lathe was somewhere in the neighborhood of 15 rpm, but the torque at that speed is lacking and the controller tended to hunt a little. It really isn't meant to turn large diameter stuff any way.Not sure if it's the right term or not, but a change in spindle speed by changing the gearing between the motor and spindle, rather than changing the motor speed. A lot of older lathes do this by using the spindle pulley to turn a counter shaft which then turns the spindle. Lowers speed but increases torque.
What's the lowest spindle speed on your lathe?
Had the same problem with my tailstock. Instead of dealing with the v-way, I took a little off the upper/lower interface.Low gear is about 15 or 20 rpm to about 900. High speed was a little over 2000. I think the high sides will increase as it breaks in. When I first turned it on during the break in procedure, top speed was about 840 in low.
I made a new tail stock lock handle and noticed some taper. The tail stock is a little high so I need to work on that.
I already have a 5" 3 jaw chuck to go with it. I need recommendation on a 4 jaw.
Wanted to create a hand wheel to use while tapping or using a die. Might use it for hand turning short threads as well. Had a wood disk laying around so I chuck it up to gauge what size the final one needs to be for leverage.
Back size view of the expanding section. Hole near the disk is for a pry rod to hold it still while tightening the expanding bolt.
Going to start on another expander to mount up a gear type indexing wheel setup. I turned this one a little lose in the bore where it expands so it doesn't sit as true as I want it for the indexing system.