Improving your old tools

zmetzing · June 10, 2016, 2:25am

I’ve had a great set of hex drivers, made in the USA, from back in my college days. However, they keep falling out of my impact driver, as they were originally designed to be chucked up in a cordless drill.

Under the excellent guidance of @wandrson, I cut retaining grooves in the shafts so that my driver’s retaining system keeps them from falling out!

We used the indexing head to hold the non-shaft end of the bit, and turned the bit slowly while milling on the Bridgeport with a ball end mill.

Woot!

(edit: Picture is an original bit, reference bit for groove position and depth, and modified bit.)

jast · June 10, 2016, 2:29am

Does this belong here? EDIT (also)

zmetzing · June 10, 2016, 2:29am

Hmm. I think I can cross-post. Now how to do that …

talkers · June 10, 2016, 2:36am

huh. i would have thought the lathe as the first choice. I’ll need to ask more about this.

zmetzing · June 10, 2016, 2:39am

That was my first thought as well, @wandrson convinced me that the ball end mill had the right profile and would produce a far better groove profile for my application.

I have two more to do, so I’ll take pictures of the setup and put them on here when I finish them.

(edit: We used a TiN-coated carbide 1/4 end mill, as the metal the bit was made out of was very hard, but not impossible, to scratch with a file. Grinding our own HSS tool with the correct profile would have worn out the HSS rapidly, as Walter pointed out)

talkers · June 10, 2016, 2:41am

pics (and Video! ) would be greatly appreciated. Thanks!

zmetzing · July 16, 2016, 11:34pm

No video (sadly), but here’s a few photos of the setup. Thanks go, again, to Walter, for lending me his smaller rotary table so that the chuck teeth didn’t get in the way of the Bridgeport’s spindle.