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Powering other tools with a Shopsmith
Posted: Sat Jul 18, 2020 1:58 pm
by edma194
In this case I want to drive my 14" bandsaw with a Shopsmith to take advantage of variable speed. (see note below)
The bandsaw is too big to try to mount on the auxiliary tubes, it would end up with the table 6 inches higher than the SS bandsaw and aligning it would be quite difficult, it has a cast iron body and might weigh as much as 100 lbs.
My initial plan is simple, I'll put a pulley on the auxiliary spindle, place the bandsaw on it's stand in front of the Shopsmith, and connect them with a V-Belt onto the bandsaw lower wheel spindle. The saw is on a wheeled dolly that I can adjust to position and align the pulleys, and to put tension on, then lock down the dolly.
I was just wondering if anybody has ideas in general for powering other devices. I've been wondering about using a CV axle to connect spindle to spindle where they cannot be aligned, or using a heavy-duty flex shaft or even using a hydraulic pump and motor. Anything others have done like this might spark some new ideas.
**A note on variable speed: I often see people online asking about the Shopsmith and if it's worthwhile getting one instead of using several separate machines. The answers rarely point out that you get continuously variable speed in every function of the Shopsmith, this results in all of it's functions being more versatile than you'll typically find in other tools. Why would I want to settle for a bandsaw that has a high and low speed requiring a belt change when I can dial in the blade speed that works best for the wood and type of sawing?
Re: Powering other tools with a Shopsmith
Posted: Sat Jul 18, 2020 4:32 pm
by JPG
Mechanically/physically it is doable. Issue would be safety re the belt.
Re: Powering other tools with a Shopsmith
Posted: Sat Jul 18, 2020 4:54 pm
by rpd
Can you mount it on the cart at the correct height to power it with a coupler from the auxiliary spindle.
There is a seller on ebay that 3d prints longer couplers.
this is one of the models he makes.
[youtube]
https://www.youtube.com/watch?v=6T27VmtxM3E[/youtube]
Re: Powering other tools with a Shopsmith
Posted: Sat Jul 18, 2020 5:35 pm
by edma194
I could use the lower auxiliary spindle. If I can mount the saw close to edge of it's cart to minimize the length of the connector it might be doable. I think that's still going to be at least 10 inches because of the extra distance the legs stick out.
I was wondering about something similar but putting a couple of U-joints or in the shaft. Very small misalignments put a lot of stress on the bearings at both ends, elastomeric connectors don't alleviate much of that and I think it's going to be difficult to maintain alignment on two separate machines.
I'd love to figure out a way to mount the saw on the Shopsmith. It could be permanent because I just picked up another 500 just for this purpose that I'll make into a shortie. I think it would take a serious modification to the base to allow it to mount. Another possibly is attaching the base at that end directly on the bandsaw cart instead of the regular legs. With a connector to the lower aux spindle the bandsaw table would be about 42.5 inches high, not at all unreasonable, lower than the SS bandsaw I think. Or I could fabricate a platform mounted on the standard legs to hold the saw. I know some great metalworkers who could do that pretty easily I think.
JPG, I can't see using a belt as I described as a long term solution. I guess I could make a belt cover for safety but I still don't like it much, just a way to get the bandsaw running to start with.
Re: Powering other tools with a Shopsmith
Posted: Sat Jul 18, 2020 6:35 pm
by JPG
Realize that the idler shaft runs 1.6x faster than the drive shaft.
So at 'slow' the idler shaft is running over 1100 rpm.
If my math is correct, in bandsaw speak that is over 4100 ft/min.
Re: Powering other tools with a Shopsmith
Posted: Sat Jul 18, 2020 6:43 pm
by jsburger
edma194 wrote:I could use the lower auxiliary spindle. If I can mount the saw close to edge of it's cart to minimize the length of the connector it might be doable. I think that's still going to be at least 10 inches because of the extra distance the legs stick out.
I was wondering about something similar but putting a couple of U-joints or in the shaft. Very small misalignments put a lot of stress on the bearings at both ends, elastomeric connectors don't alleviate much of that and I think it's going to be difficult to maintain alignment on two separate machines.
I'd love to figure out a way to mount the saw on the Shopsmith. It could be permanent because I just picked up another 500 just for this purpose that I'll make into a shortie. I think it would take a serious modification to the base to allow it to mount. Another possibly is attaching the base at that end directly on the bandsaw cart instead of the regular legs. With a connector to the lower aux spindle the bandsaw table would be about 42.5 inches high, not at all unreasonable, lower than the SS bandsaw I think. Or I could fabricate a platform mounted on the standard legs to hold the saw. I know some great metalworkers who could do that pretty easily I think.
JPG, I can't see using a belt as I described as a long term solution. I guess I could make a belt cover for safety but I still don't like it much, just a way to get the bandsaw running to start with.
The lower aux spindle is for the jointer only. It rotates 1.6 times faster than the upper spindle. You run a real danger of seriously over speeding the band saw. I am not sure that the lowest speed is low enough for the band saw.
Re: Powering other tools with a Shopsmith
Posted: Sat Jul 18, 2020 6:50 pm
by JPG
I think if I were to use a dedicated SS, that I would include a jackshaft at the elevation the bandsaw needs. That also allows a speed reduction from the drive shaft low speed of 700 rpm. Small pulley on drive shaft and larger pulley on the jackshaft. Belt would be fairly inaccessible.
That leaves thee with the jack shaft to band saw connection to figger out.
Re: Powering other tools with a Shopsmith
Posted: Sat Jul 18, 2020 7:00 pm
by edma194
JPG wrote:Realize that the idler shaft runs 1.6x faster than the drive shaft.
So at 'slow' the idler shaft is running over 1100 rpm.
If my math is correct, in bandsaw speak that is over 4100 ft/min.
jsburger wrote:The lower aux spindle is for the jointer only. It rotates 1.6 times faster than the upper spindle. You run a real danger of seriously over speeding the band saw. I am not sure that the lowest speed is low enough for the band saw.
Ah, there's the rub. Even the upper
shaft is running pretty fast to take advantage of the variable speed. A reduction pulley will be needed.
Re: Powering other tools with a Shopsmith
Posted: Sat Jul 18, 2020 7:42 pm
by rpd
some ideas here for making a
jack shaft.
http://www.mkctools.com/jackshaft.htm
Re: Powering other tools with a Shopsmith
Posted: Sat Jul 18, 2020 7:49 pm
by jsburger
edma194 wrote:JPG wrote:Realize that the idler shaft runs 1.6x faster than the drive shaft.
So at 'slow' the idler shaft is running over 1100 rpm.
If my math is correct, in bandsaw speak that is over 4100 ft/min.
jsburger wrote:The lower aux spindle is for the jointer only. It rotates 1.6 times faster than the upper spindle. You run a real danger of seriously over speeding the band saw. I am not sure that the lowest speed is low enough for the band saw.
Ah, there's the rub.
Even the upper shaft is running pretty fast to take advantage of the variable speed. A reduction pulley will be needed.
No, the SS band saw runs off the upper
shaft. Yes you can still over speed it but not at the low range of the SS head stock where it is supposed to run. You can still change the speed within the range of a band saw.
BTW, there is absolutely nothing wrong with the SS band saw. It is a great saw.