Speed Reducer Option

[edma194]

The Shopsmith Speed Reducer uses belts. This video shows the innards: https://www.youtube.com/watch?v=fDe9-NnxcHk&t=67s

[reible]

If you move the bandsaw to the other end then the "drill" rotation will be correct, right?

Ed

[miken]

If you move the bandsaw to the other end then the "drill" rotation will be correct, right?

Ed

Yes, I believe you are correct. Duh, I didn't even consider that. I've never setup any SPT on that side, never crossed my mind. Embarrassing.
Mike

[edma194]

I'm a little confused about the direction also. Are you running the Versamatic without either end held stationary? Sounds like that is doing the reversal of direction.You just need some kind of arm attached to the way tubes and a band clamp to hold down one end and reverse direction. Mounting the bandsaw on the other end also works, and if you only want to use this cleverly configured speed reducer in one direction for the band saw perhaps you don't want to do anything else but it might be useful for some users to be able reverse the direction of the output.

There is probably some simple planetary gear layout that would reverse rotation without reducing speed. That might be quite useful to owners who don't want to invest in a PowerPro or modify their motors.

[miken]

Are you running the Versamatic without either end held stationary?

No, that wouldn't do anything. It would just free spin on the drive side, and no rotation at all on the output side. The collar must be held still. I was holding it with my hand for testing. As you said, I need to build a simple arm to hold it. I think it will work great for as long as it lasts.

[Edit] I should have said I think it will work for reducing the rpm. However, 115 rpm is still around 300 sfpm, which is still fast for cutting steel, but I am going to try this before buying a portaband.

Mike

[edma194]

I like the idea, might even set up an extra bandsaw with a metal cutting blade to try it. I have the Shopsmith speed reducer and a PowerPro so I can get down to very low speeds. I have a horizontal cutoff saw that can be used in vertical mode, but it's pretty shaky in vertical mode and there's just a 4"x4" piece of steel for the table. I just finished refurbing the old beast for regular horizontal cutoffs, it turned out to be a fight, but that's a story for another day.

[miken]

Let me know how it works out if you try it.

Thanks, Mike

[JPG]

I'se confused.I thought the versamatic was reversible(drives/removes screws).

It's a bit difficult to explain how it works. I dont fully understand it. The one I have is meant to be driven clockwise by a non-reversing drill (or reverse on the SS). The way you get it to turn counter clockwise is you unscrew the front drive spindle and the clockwise input rotation is somehow reversed and it magically turns counter clockwise. If you try to drive it counter clockwise it does not output counter clockwise, it just disengages and free-spins. Here is a video on how it works https://youtu.be/Q4ljIAIZ3w0 . I think the model 4600 is direct drive and only meant to drive in screws, therefore, reversing input rotation also reverses output rotation.

P.S. I think your setup has it running reversed(screw removal mode).

Yes, screw removal rotation (counter clockwise) drives the bandsaw in the correct direction to cut.

[Edit] by the way, it does nothing until you hold the outside collars still with your hand. Hold drive side collar still with spindle extended drives it counter clockwise. Hold front collar still with spindle screwed in drives it clockwise.

Mike

Ahh now I remember it assumes typical drill rotation(cw).

Yep ss reversed!

[larryhrockisland]

Cool idea!
Used to have one of those. It was a cheaper version I got around 1980. I used it to drive wood screws with an electric drill, I have a recollection that it was frozen last time I tried it. Lubrication will be an issue with continuous use but they were meant to reduce from high speeds in drills so the driving them from the slow setting won't be that hard on the gears. Using one of these to reduce bandsaw blade speed for cutting metal is great idea. You may want to twist the blade 45° with the blade blocks so you can cut off long stock.

Scott has a video about twisting the blade. https://youtu.be/5lqzmibP3vg He wasn’t a fan and and I believe the blade isn’t good for regular cuts after twisting.

[edma194]

Blade twisting is not that exotic. Plenty of cutoff saws have been made that way. It allows long lengths of narrow stock to be cut with a relatively short bandsaw throat. I tried it out on SS band saw long ago, I was just curious, it worked, and I used that blade for quite a while after that. I just refurbished an old horizontal metal cutting band saw that uses a twisted blade, just like every other one I've ever seen. Yes, it looks strange, but it's no more strange than using a ribbon of flexible metal welded into a circle as a saw blade in the first place. Metal is ductile, it will return to it's original shape after being deformed.