Wall-mounted motor & countershaft

[dan97526]

I am hoping to wall mount my lathe motor and countershaft, something on the order of this:



My questions are about tensioning both the motor belt and the flat belt.

I was thinking of hinging the motor shelf so the motor belt would tension under gravity. I don't love this solution, but it would be easy enough to accomplish. Another idea I had was to bolt the motor to angle iron mounted to the wall. Maybe add a spring belt tensioner, although I don't know where to look for one that isn't an auto part.

On the other hand, I need to be able to remove and re-tension the flat belt in order to change speeds. I've seen pictures of what looks to be a handle system, but the pictures all lacked any accompanying explanation.

Ideas? Best practices?

Thanks in advance.

 

[GL]

Based on the picture, the fundamental problem is both belts need to tension by moving the jack shaft up, but having both happen at the same point is not likely without some horsing around. My Craftsman has a jack shaft that has an over center lever tensioner to tension the v belt to the spindle step pulleys. The motor pivots and hangs off the belt on the other end of the jack shaft. Mine is part of the lathe, but remoting it to the wall would work in your case. The jack shaft would pivot up and away from the spindle, but the lever to pivot it would over center and lock it. That bracket would need to be adjustable to set tension on the flat belt, amount of slot for the bracket dependent on your geometry. Motor belt tension set by motor pivot hanging geometry. Just a thought. Not sure how much tension is required on a flat belt, but g-string tight (the guitar string kind, not the other kind) doesn't seem to be how the run.

 

[benmychree]

If the flat belt is properly tensioned by splicing to the right length, and run off the pulley when not in use, it will work fine, you just roll the belt back onto the pulley, that way the belt does not get stretched by being under tension, it was done that way in the old days, and it still works, that is the way my 9" Monarch is set up with the countershaft overhead and the lathe on floor legs. If you hinge the motor for tension, it should have a turnbuckle to adjust tension and hold the motor from bouncing around under load. The good thing about the setup you show is that the bench does not have to be nearly as deep as when using the SB bench mounted countershaft that has the over center tensioner.

 

[dan97526]

Found something that is actually closer to what I have in mind (thanks to the ingenious gentleman on GarageJournal from whom I stole it):



The problem with this is that I don't see any way to relax tension on the flat belt. I can see how he is using the plate to tension the motor belt though.

 

[matthewsx]

The flat belt on my Seneca Falls has a built in tensioner controlled by a knob. When I changed over to a flat fan belt and mounted the motor underneath the bench I made a tensioner for the motor belt with some square steel and an idler pulley designed for lawn equipment.



With the setup above it's probably fine to leave tension on the jackshaft since it's running on pillow blocks with lubricated bearings. The tension there can be adjusted by moving the motor up and down.

You can see part of it in the lower left hand corner of this photo.



You may even be able to use something from an old riding mower if you have that sort of thing lying around.

Cheers,

John