Low speed for 12" disk sander

[Pete Staehling]

I went ahead and made a 12" disk to run on the lathe. I still have to make a table for it. I figure one that mounts on the banjo is probably the easiest way to go. I seldom tilt the table on the HF so it probably wont tilt, but it will have a miter slot and miter gauge or at the very least a little sled permanently set at 90 degrees.

I am really impressed with how nicely it sands when you have the ability to control the speed. I am just using the tool rest in lieu of a table at this point. That is less than ideal, but it is good enough to get a feel for how the disk works at low speed. You can completely eliminate any burning and have much more easily controllable sanding for precise work.

I don't know why more sanders don't come with speed controls. Sure there would be a price hit, but a VFD option would be worth it IMO. As it is, I will live with the higher speed HF model and use the lathe for low speed sanding.

[Darcy Warner]

Be cheaper to buy a 16" 3phase sander and buy a 200.00 vfd than screw around with what you have.

[Larry Frank]

I love the flexibility of my Shopsmith for all kinds of sanding things and my 12" disk sander.

[Pete Staehling]

I love the flexibility of my Shopsmith for all kinds of sanding things and my 12" disk sander.

I hope that the lathe setup will add some of that same flexibility for me.

Be cheaper to buy a 16" 3phase sander and buy a 200.00 vfd than screw around with what you have.

I can see how you might say better, but cheaper? Not sure how it can be cheaper since I am spending essentially nothing on what I have now and am retired and only doing business as a hobby now so am not really losing business productivity.

As far as finding one for $200... I assume that would have to be used. They seldom come up used here. I don't recall seeing one come up locally and even if I branch out to distant locations the prices I see are much higher with most in the $750-1500 range. Maybe once in a while one shows up at $500. I have not seen one for $200 and doubt I am likely to especially locally.

If I was willing to go through the hassle and expense a three phase motor and vfd for my existing sander would be doable for a few hundred for new stuff.

A 16" disk sander with a vfd would be nice but pretty gross overkill for my work since most of it is building travel sized dulcimers. A 12" is already luxuriously large.

[Darcy Warner]

200 for vfd.

[Pete Staehling]

Just a quick update...
I made a table and a little sled for the lathe mounted disk that is essentially a miter gauge fixed at 90 degrees. I have used it a little to shape some tiny parts (bridges and nuts for dulcimers) and some larger parts and am delighted with it. It works with my existing jigs just fine only much better than with the high speed grinder.

The table is mounted on the rails of the lathe and attaches and removes very quickly. The top of the table is cut from an aluminum table from an abandoned router table that already had a miter slot. The support for it is essentially a plywood box.

The disk part is plywood and has a plywood backer plate with an aluminum ring that quickly mounts it on the lathe chuck. The whole thing can come on and off the lathe in seconds.

Running at a little under 500 rpm it is a joy to use. No burning and much more control for detailed precise work.

[Mike Henderson]

Just a quick update...
I made a table and a little sled for the lathe mounted disk that is essentially a miter gauge fixed at 90 degrees. I have used it a little to shape some tiny parts (bridges and nuts for dulcimers) and some larger parts and am delighted with it. It works with my existing jigs just fine only much better than with the high speed grinder.

The table is mounted on the rails of the lathe and attaches and removes very quickly. The top of the table is cut from an aluminum table from an abandoned router table that already had a miter slot. The support for it is essentially a plywood box.

The disk part is plywood and has a plywood backer plate with an aluminum ring that quickly mounts it on the lathe chuck. The whole thing can come on and off the lathe in seconds.

Running at a little under 500 rpm it is a joy to use. No burning and much more control for detailed precise work.

I did almost the exact same thing. But I haven't used it very much primarily because of the setup and teardown time. It certainly takes me more than "seconds" to set up - heck, even getting the stuff out of storage takes a fair amount of time. If I had it set up all the time I'm sure I'd use it more but I can't tie up my lathe with that.

If I had the room, I'd get a dedicated machine, maybe a 3-phase and then add a VFD.

Mike

[Pete Staehling]

200 for vfd.

Yeah, my bad. Even more reason to say there would be nothing cheaper about a 16" sander and vfd. It would be a pretty big investment and pretty gross overkill for my tiny shop and small work pieces.

[Pete Staehling]

I did almost the exact same thing. But I haven't used it very much primarily because of the setup and teardown time. It certainly takes me more than "seconds" to set up - heck, even getting the stuff out of storage takes a fair amount of time. If I had it set up all the time I'm sure I'd use it more but I can't tie up my lathe with that.

I hope it will work out better for me, but time will tell. I have the two components on a shelf above the lathe. If the chuck is on the lathe it takes 30 seconds to install both pieces. It would become more of an issue if there were a project chucked up in the lathe and i probably would tough it out on the high speed stand alone sander at that point, but the good news is that when working on a lathe project I typically stay with it until completion and leave the lutherie work or woodworking project go until I am done with the lathe project.

If I had the room, I'd get a dedicated machine, maybe a 3-phase and then add a VFD.

I have a dedicated benchtop 12" machine, but it is not 3 phase (are any of the 12" bench tops 3 phase?). If I find that switching modes on the lathe is too much of a pain I may look for a 3 phase motor that fits my bench top and get a vfd. Truth be told the vfd is really overkill imo. I am finding I am happy with just running it at 500 rpm or a little less. So the two motor, two speed solution or a step pulley solution would be just fine and may be doable for less $$$ and I could probably even live with a single speed low speed solution.

[Robert D Evans]

Simple way to make a platform for your wood lathe is to get a piece of 3/4" galvanized pipe with the pipe threads on at least one end. Screw it onto a 3/4" floor flange and screw the floor flange onto a piece of 3/4" plywood. Cut the galvanized pipe to length so the platform centers on the sanding disk. The 3/4" galvanized pipe will fit nicely into your banjo and you can easily position it where ever you need to. Rock solid, and easy to install and remove.

If you can get a pulley on the grinder shaft, you can use a treadmill motor and speed controller to coble something variable speed together. Most of those treadmill motors are 2-4 hp and people use them to make their wood lathes variable speed. Of course the sawdust will eventually destroy the treadmill motor but you can get those things cheap or free off of Craigslist.

Just a few thoughts.

[Pete Staehling]

Simple way to make a platform for your wood lathe is to get a piece of 3/4" galvanized pipe with the pipe threads on at least one end. Screw it onto a 3/4" floor flange and screw the floor flange onto a piece of 3/4" plywood. Cut the galvanized pipe to length so the platform centers on the sanding disk. The 3/4" galvanized pipe will fit nicely into your banjo and you can easily position it where ever you need to. Rock solid, and easy to install and remove.

I considered going that way but had scrap 3/4" plywood on hand and made a box that sat on the rails. A piece that drops between the rails and turns 90 degrees before tightening a wing nut locks it in place. I like that the base is keyed into the gap between the rails so the miter slot in the platform automatically registers at the correct angle to the face of the disk.

I find it is just as quick as the banjo mount that I was going to use. I think I prefer the way I went, but both are good solutions.

If you can get a pulley on the grinder shaft, you can use a treadmill motor and speed controller to coble something variable speed together. Most of those treadmill motors are 2-4 hp and people use them to make their wood lathes variable speed. Of course the sawdust will eventually destroy the treadmill motor but you can get those things cheap or free off of Craigslist.

I assume you are talking about the dedicated grinder here. I may do just that if I run across a free treadmill, but after using the lathe as a sander a while I am not really finding variable speed to be a big deal so much as just low speed. I would be pretty happy with a single low speed of 500 rpm especially if the grinder also could be used in it's original configuration. So I may just use a speed reduction in the pulleys and a single speed motor when/if i get around to it. I am less motivated to get to it now that I have the lathe set up working.