Shopsmith Forums

Hi all, I got lucky and found a Mark VII a couple hours from me. I have been looking for a backup motor mostly, but a backup speed cam and another 3-button switch also adds to the peace of mind. They never come up on ebay, so I made the drive and bought the whole machine for $400. Even the gear rack on the upper tube was good, but unfortunately no casters. It also came with a 4" Jointer and a band saw (older Magna branded), and some other odds and ends. It just so happened that another tool I had been casually looking for also popped up on a Facebook Marketplace estate sale, and it was only 15 minutes from my house. It's a 12" Atlas metal lathe, undermounted motor on the original stand, with a quick change gear box and many attachments and tooling. I couldn't resist and have been busy lately cleaning that up.

Anyway my question; I already have my grandfathers 12" Craftsman bandsaw which works excellent, so I am thinking of using the Shopsmith bandsaw as my metal cutting saw and building the homemade speed reducer Scott Markwood builds in this youtube video https://www.youtube.com/watch?v=5ZNIDkewy0U

Wondering if anyone has built it, and was the speed good for metal cutting? In the video Scott talks about reducing the minimum Shopsmith speed of 700 RPM down to 138 rpm which sounds great, but a Lenox bi-metal speed cutting chart online listed speeds in feet per minute. I found an online calculator that lists a 10" wheel turning at 138 rpm is actually cutting at 361 feet per minute, which is still too fast.

Just looking for opinions, if it's worth building, etc.

Thanks, Mike -

miken wrote: ↑Fri Jul 23, 2021 9:59 pm ... In the video Scott talks about reducing the minimum Shopsmith speed of 700 RPM down to 138 rpm which sounds great, but a Lenox bi-metal speed cutting chart online listed speeds in feet per minute. I found an online calculator that lists a 10" wheel turning at 138 rpm is actually cutting at 361 feet per minute, which is still too fast.

Just looking for opinions, if it's worth building, etc.

You should be able to find pulley sizes to get the rotational speed down into the range you want. Personal opinion: I wouldn't have the exposed belts and pulleys in my shop for anything beyond a short term experiment. If I needed the capability I'd buy the SS speed reducer, primarily because it is much safer. As a bonus, it has turning capability, and resale value. I'm not sure if it will get you the speed you are after, I understand it is 7:1 so 100 RPM on a conventional headstock.

- David

WIth the PowerPro and a speed reducer you can get down to maybe 35 rpm.

Whether you need that or not depends on what you are doing. I have an old Harbor Freight portable band saw that I mounted on a swing arm to make a horizontal bandsaw that I have used a lot as a cut off saw for metal. It works quite well. If I were going to cut through something quite hard and thick steel I'd stick to slow speeds but I have used higher speeds on mild steel and aluminum without problems, and I'm using Lenox bi-metal blades too. You can find a bunch of videos on YouTube about making cutoff saws from the portable bandsaws, and now you can buy a base and arm to mount one on too.

Good point about the open pulleys David, not exactly safe. I didn't think that far ahead.

Ed, I did consider a harbor freight Bauer brand porta-saw. It probably is the best option. I was hoping to utilize the shopsmith bandsaw for something useful. I will look into the base and arm you mentioned.

Thanks for the replies,
Mike

I have a speed reducer for sale. Will have to figure out what is a reasonable price.
Richard

rmoore wrote: ↑Sun Aug 08, 2021 4:52 pm I have a speed reducer for sale. Will have to figure out what is a reasonable price.
Richard

I'd be interested for a decent price. Mike brought this subject up so he can have the first shot at it.

edma194 wrote: ↑Sun Aug 08, 2021 5:03 pm

rmoore wrote: ↑Sun Aug 08, 2021 4:52 pm I have a speed reducer for sale. Will have to figure out what is a reasonable price.
Richard

I'd be interested for a decent price. Mike brought this subject up so he can have the first shot at it.

I am interested, pm me a price. I am thinking that at 100 rpm I am still at 261 feet per minute, which is on the high side for carbon steel. I am leaning toward a harbor freight portasaw.

Thanks, Mike

rmoore wrote: ↑Sun Aug 08, 2021 4:52 pm I have a speed reducer for sale. Will have to figure out what is a reasonable price.
Richard

Do you still have it or did you sell it already? Either way, thanks..

A metal cutting bandsaw or similar would be a better way to go.

Adapting the Shopsmith Bandsaw seems to be a challenge. I wonder if the Speed Reducer can be made to work. That is an accessory I have not had. Can the Speed Reducer be connected to the Drive Sleeve shaft since the bandsaw needs to run in the correct direction? A reversing Headstock like the Power Pro or old Mark VII can reverse allowing the Speed Reducer to be mounted in it's normal position off the Quill. Second, can the Speed Reducer be run in the reverse direction? If not, neither mounting option will work. The Speed Reducer is a 7:1 reduction so it could go down to about 35 RPM's on the Power Pro Headstock as edma194 said.

Another option would be to set up the Bandsaw on a separate stand with it's own motor. A 1715 RPM Motor with an 1-1/2" pulley going to an 8" pulley on the Bandsaw will run at 320 RPM's. An intervening step pulley setup could get it lower and could reduce the needed pulley size at the Bandsaw's shaft.

chapmanruss wrote: ↑Tue Sep 07, 2021 12:46 pm A metal cutting bandsaw or similar would be a better way to go.

Certainly. But if it were to be done with a Shopsmith bandsaw...

Another option would be to set up the Bandsaw on a separate stand with it's own motor. A 1715 RPM Motor with an 1-1/2" pulley going to an 8" pulley on the Bandsaw will run at 320 RPM's. An intervening step pulley setup could get it lower and could reduce the needed pulley size at the Bandsaw's shaft.

A second reduction stage is definitely needed. I think driving the bandsaw in the range of 50-100RPM should do the job for even hardened steel.

At that point perhaps the speed reducer should be considered. The 700RPM output from the conventional headstock needs at least 10:1 reduction still. The 7:1 result from the speed reducer is feasible though if care is taken. No problem at all if mounted on a PowerPro. I recently acquired a Speed Reducer, have only mounted it to make sure it worked, but did try it at 250RPM to watch it turn oh so slowly. Don't see any reason it can't mount on the left side of the headstock and drive a bandsaw with a carbide blade to cut steel. I still can't see why though, the feed rates will be incredibly slow and I have so many other ways to cut that metal.