Arbors and Chucks with angled bores for retaining setscrew

[everettdavis]

In attempting to answer a question on a Nova Chuck Adapter that came up in a thread about a Power Pro Headstock we got into a discussion about the angled bore in chucks and arbors for the setscrew that holds them on the spindle.

I posted this picture in that thread and we determined that Shopsmith appears to have made some that were drilled straight and some that were at an angle.

Compare Saw Arbor to Nova Lathe Chuck Adapter.png (749.11 KiB) Viewed 2492 times

My understanding was, til that point that one could identify the Shopsmith provided ones because of the angle bore, opposed to straight bores for arbors for other equipment.

It now appears to be a mixed bag based on other forum members who commented they have both types (from Shopsmith).

So I started this thread to see if we can find when angled bores first appeared in arbors and chuck adapters etc.


I don't know for certain when the angled bore for the setscrew originated, but it was also illustrated in the Model 710 MAGNA 9" Saw sold by Magna Power Tool Corporation which came from the recent cache of documents from Hans Goldschmidt's files I scanned last month.

That machine pre-dates Shopsmith Inc. which incorporated 1972 by a number of years.

See Arbor Illustration (below) taken from that manual, which I uploaded into the From Hans Goldschmidt folder under My Google Drive if you need one.

How Arbors Are Used Model 710 Magna Table Saw.png (337.61 KiB) Viewed 2492 times

I will have to research further to see when it was first documented, if such a document can even be found.

Just one more thing in the History I need to research... as if I needed more...

Everett

[everettdavis]

In 1957 Shopsmith applied for a patent that held the retaining nut on the back side of the arbor to prevent the blade from flying off the arbor. In this drawing, the set screw is not drilled at an angle.

I have not found any prior to 1957 that were angled. Equally, I have not yet located a Shopsmith patent application wherein the angle of the setscrew was defined. I don't know when it was introduced so far.

Everett

1957 Saw Arbor Patent Application - blade cannot fly off arbor.png (187.3 KiB) Viewed 2399 times