Speed Reducer Option

[miken]

Hi, I was thinking maybe this could help others looking for options to slow down their Shopsmith for drilling, bandsaw, jig saw, etc.
I came across a vintage Versamatic speed reducer for $6. They are pretty common on eBay for varying prices but I found one at a flea market, and for $6 it was worth a shot. It works surprisingly well.

My Mark VII runs well over the minimum 700 RPM advertised. I tried slowing it down with different v-belts of varying widths/lengths, and even shimming the idler with little success (thanks JPG for trying to help with that). Even 700 RPM would have been way too fast to cut metal on the bandsaw, which was what I was trying to do. I then considered building the pulley system speed reducer Scott Markwood made in his YouTube video here: https://www.youtube.com/watch?v=5ZNIDkewy0U but winter set in and I set the Shopsmith aside. Today I connected the Versamatic to my Mark VII and it works very well at reducing the speed of my bandsaw. I need to run the Shopsmith in reverse, so this may not work for everyone without some modification. These things were made before reversing drills, and they not only reduce the RPM, but can also reverse the rotation. I will need to make an arm to hold the collar still. They work by holding the front collar and it turns at the reduced speed, hold the back collar and it turns in reverse at the reduced speed. Anyway, just thought I'd share.

Mike -

[edma194]

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.

[miken]

Cool idea!
You may want to twist the blade 45° with the blade blocks so you can cut off long stock.

I will have to play around with this "twist the blade" concept. Great idea! I haven't really thought much about actual usage as I had basically given up on using the SS and was looking to buy a cheap porta-band. I imagine I would need to loosen the blade tension some to twist the blade?

The old drills used to spin around 2000 RPM, with no variable speed. I think it could last a while at 900 RPM. I did take it apart, clean, and replace the grease. The Versamatic is also designed for thread tapping in steel, so it can likely handle the torque. If not, I'm only out 6 bucks.

I may need to make a better coupling. For testing i have an 11mm craftsman socket stuck in the 5/8" SS drive hub.

Thanks, Mike

[JPG]

Good Idea!

I question 'durability'.

[miken]

I question 'durability'.

I can't argue that. Definitely not a precision tool. No bearings and lots of metal on metal contact.

Mike

[miken]

Just FYI, there is another model type, no. 4600 that I think would work on the Mark V without the need to run the Shopsmith motor in reverse.

Mike

[JPG]

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

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

[SteveMaryland]

Planetary gearset inside?
Is a planetary used inside a Shopsmith speed reducer (which also claims 7:1)?

A neat simulator of these devices: http://www.thecatalystis.com/gears/

[miken]

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

[miken]

Planetary gearset inside?
Is a planetary used inside a Shopsmith speed reducer (which also claims 7:1)?

A neat simulator of these devices: http://www.thecatalystis.com/gears/

Yes, it has a planetary gear inside, but only on one side, the other side has some threading that reverses the output rotation. Cool website link. I dont know how the SS speed reducer works, but I assume its a similar planetary system.