Update on my sanding disc for a lathe

[Alex Zeller]

The idea of having a sanding disc that could be mounted to the lathe (as others have done) seamed to get plenty of interest. I figured I would start a new thread to show where I'm at. To finish it I need to get some steel. I recently switched trucks and don't have a rack for the new truck so until I do or if I need the table it'll probably just wait. Right now I'm leaning towards not making the table tilt (other than being able to adjust it to be at exactly 90°). The table is from an old Craftsman tablesaw that a friend was going to throw out. I cut the hole for the blade out and bolted the two halves together. The table is just set on some blocks to see what height would work best.

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Here's a few pictures of the MT#2 adapter holding the chuck with the cole jaws to flatten the bottom of a bowl (most likely would never need to do it but it would work to flatten a segmented ring). The one thing to note is that the adapter must be seated well into the tailstock or it will spin. The maker says to use a 3/8" threaded rod to do it. You can't leave it in place and use the handwheel on the tailstock to move the chuck. You either need to use the rod to pull the adapter tight and then remove it or leave it in and slide the whole tailstock assembly. I think it comes down to how accurately machined the adapter and the tailstock's MT#2 are.
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The last picture is the rim of a bowl after flattening it by holding the bowl by hand against the disc and another one to show what the before looked like. Over all I would say it works well.
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[John K Jordan]

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The one thing to note is that the adapter must be seated well into the tailstock or it will spin.

As I mentioned before, instead of relying on the friction of the Morse Taper, find some way to hold the chuck or adapter to keep it from turning.

On some things like taper shank drill bits I use vice grips to prevent rotation. My chucks (Nova) all have inserts made like large hex bolt heads so I can hold them with the chuck wrench. It looks like yours may take a tommy bar rod or even use work with the allen chuck key. It wouldn't take too much to grind or machine flats on the small diameter section at the bottom of the chuck shown.

Whatever means you use to hold the chuck, rod or whatever, it can be held in the hand but it's much easier to it from turning with the tool rest. Back off the tailstock enough to put the banjo between the chuck and the tailstock. Rest the rod or vice grips or whatever on a short tool rest in the banjo. No more rotation.

Or leave the bowl mounted in the headstock and put the sanding disk in the tailstock and add a bar or rod to the back to contact the lathe bed to prevent rotation. Or do what some people do and don't advance the tailstock with the crank but slide it along the ways by hand - that way maybe you can use a drawbar on the MT adapter.

If you do let the taper rotate even once in the socket, be careful of galling the MT surfaces. The male taper on the adapter can be fixed with a file but the socket is much easier to repair with a MT reamer. https://www.amazon.com/gp/product/B07933VYD7

JKJ