Shopsmith Forums

Has anyone ever thought of the idea of a extendable power coupler? So that when you get the table saw all set up the way you want and you maybe want to remove the jounter,band saw, ect you don't have to move the table saw set up. It would be neet to slide the coupler together and remove the SPT.

rbenstead wrote:Has anyone ever thought of the idea of a extendable power coupler? So that when you get the table saw all set up the way you want and you maybe want to remove the jounter,band saw, ect you don't have to move the table saw set up. It would be neet to slide the coupler together and remove the SPT.

I fabricated a regular coupler that unscrews in the middle (has to have left hand threads) to disconect a SPT without moving the headstock. It will work but I am still not happy with it. You could make a longer telescoping shaft much like a scaled down tractor PTO tumbling shaft but it would present many of the same dangers the tractor ones do and would need very careful guarding.
Just do a Google image search on:
PTO shaft
The standard SS coupler will quickly grab a long sleeved shirt sleeve and do great damage (to the sleeve and arm both) in an instant.

Interesting idea, but it needs real engineering. On top of the issues pointed out above, a longer shaft turning those type of RPM's needs to be a careful balance of mass and strength.

It wouldn't necessarily have to be longer. The standard coupler length could be collapsed about 1 inch to be able to get it off the hubs. I know that this would take some work. But I would think that if Shopsmith would ever look at this idea I believe it would be a hit. Just a idea!

robinson46176 wrote:I fabricated a regular coupler that unscrews in the middle (has to have left hand threads) to disconect a SPT without moving the headstock. . . .

WHY? Why not let the tendency to 'separate' be used to wedge the ends against the spt and headstock shaft(self captive)? i.e. Internal thread(nut) in spt end, and external thread(screw) in 'pto' end. Then to remove the spt, screw the spt end into(towards) the pto end thus clearing the spt hub.

I leave it up to y'all to figger out how to embed the nut/screw in the coupler!

How some ever:

Previous discussions regarding EXTENDING the reach of the spt coupler so as to accommodate an extra table carriage on the pto side of the headstock offer an alternative!

In those discussions, a 5/8" sleeve coupling(or a 1/2" router adapter) were used with a short piece of shaft to allow mounting a ss hub. Consider the ss 1/2" router adapter. If a shaft(1/2") of sufficient length is used such that when slid in/out of the adapter, it changes the overall length sufficient to allow slipping the spt coupler off the spt hub. If This is too vague, I will try to mock one up for pix.

The router adapter attaches to the 'pto'. The 'sliding' 1/2" shaft with usual headstock hub in the other end, then the spt coupler.

Actually, it would seem to me that you want a coupler that could be collapsed so that it just comes off the headstock. A splined coupler would seem to have enough strength. You need someway for it to be secured in the 'short' position so that it would never(!) spring loose and hit the running headstock. Plastic would probably not be workable. Hmmmmm.

Forrest

Standard ss hub on left end.

Old mortising rod(5/8" shaft with flat) in center.

Standard 5/8" coupler on right(from grainger).

[ATTACH]8793[/ATTACH]

Coupler attaches to ss aux shaft. Coupler can be slid on flat of shaft to allow removal without moving headstock.

The ss plastic coupler goes between the adapter hub and the jointer hub.

Nice! I've had a couple occasions where something like this would be handy.