Shopsmith Forums

My apologies if this has been covered elsewhere.

The Shopsmith main table has two holes in it that provide for mounting things such as the shaper fence. I’d like to drill the same size holes in my extension tables. I don’t have much experience with drilling in heavy ferrous metal. Am I biting off more than I can chew here? What would be the right way to do this?

poihths wrote:My apologies if this has been covered elsewhere.

The Shopsmith main table has two holes in it that provide for mounting things such as the shaper fence. I’d like to drill the same size holes in my extension tables. I don’t have much experience with drilling in heavy ferrous metal. Am I biting off more than I can chew here? What would be the right way to do this?

WHY?

The extension tables are aluminum.

You’re right. And here I would have sworn they were ferrous metal.Good; that means drilling them is much closer to my pay grade.

Here’s what I’m looking at.

- I only get one chance at this, so good planning is essential.

- The aluminum of the table seems to be between 1/8” amd 3/16” thick.

- The bracing pattern on the back provides two nice round centers that would supply good support for bolts with washers. The accompanying photo shows them; they’re what the pencils point to.

- Those centers are large enough to accommodate a 27/64” bit with room to spare. That will provide an easy slip fit for bolts/screws up to 3/8” inch, plenty big enough for any reasonable purpose.

- I have a Mastercraft titanium-coated metal/wood bit set. I can regard those bits as consumables.

- I’m thinking to drill from the back using the Shopsmith drill press. It looks like the hole will come out between the ribs on the top, but it’s hard to be exact about that. I have a Dremel with some conical abrasive bits for burr clean-up.

- I’m looking at the drilling speed chart at https://store.curiousinventor.com/guides/drill_speed/ and thinking that 2000 RPM on the 27/64” bit should be good. I’m thinking to keep the bit lube with a spray can of Remington gun oil.

- Drill a pilot hole or just go for it? If a pilot hole, what size? Sorry about the upside-down photo.

The instructions for the Incra TSIII Shopsmith Table Saw Fence uses those same points to attach the mounting plate. The instructions use a 3/8 inch hole then pull 1/4 inch nuts up into them. Page 4 of the instruction pdf. https://incra.com/manuals/tsiii_shopsmith_manual.pdf

Interesting. Thanks!