Shopsmith arbors only have one set screw.

artfuldodger · Post by **artfuldodger** » Sat May 14, 2011 12:25 am

I posted earlier about motor arbors having two set screws. I work in HVAC and most motor pulleys or sheaves use key ways or at least a flat spot on the shaft to secure them to the shaft. The Shopsmith system uses a single set screw on a flat spot to secure coupler hubs, saw blades, and other attachments.
It just seems weird to me to start up a saw blade attached with just one set screw. I guess being a newby i'm just being a little paranoid.
Are there any stories of anything coming loose while spinning? How do I know how tight to tighten the attachments?

charlese · Post by **charlese** » Sat May 14, 2011 2:10 am

To be fully honest, I have had a saw blade come loose while sawing. It is an easy thing to spot. Because of the taper in the flat spot, the blade did not come off, it was just loose on the spindle. I blame a faulty set screw for the incident. My experience with loose blades was limited to this one arbor and the one blade attached to it. (Actually, this happened twice with the same arbor.) I have four arbors each are attached to an individual blade. This allows me to switch blades often.

Already mentioned the tapered flat on the spindle. This is a safety factor. Also the relative narrow width of the table insert will not let a blade come off far enough to leave the spindle.

A change in the set screw solved my loose blade issue. It was not scary - just frustrating. I change blades quite often, use the saw almost daily and am not at all worried about the use of one set screw.

JPG · Post by **JPG** » Sat May 14, 2011 2:25 am

artfuldodger wrote:I posted earlier about motor arbors having two set screws. I work in HVAC and most motor pulleys or sheaves use key ways or at least a flat spot on the shaft to secure them to the shaft. The Shopsmith system uses a single set screw on a flat spot to secure coupler hubs, saw blades, and other attachments.
It just seems weird to me to start up a saw blade attached with just one set screw. I guess being a newby i'm just being a little paranoid.
Are there any stories of anything coming loose while spinning? How do I know how tight to tighten the attachments?

The important thing is to make sure you are tightening the screw at the 'bottom' of the flat. That is make sure the screw is perpendicular to the flat. i.e. centered on the flat. Rock the arbor while tightening to make sure the arbor is not cocked on the flat. Once tightened it should not loosen by shifting position.

Since the flat is tapered, you need to make sure the arbor is pushed on all the way.