Ever use a "ring and dot" auger?

[VaughnT]

I had a fellow ask me to make him one of these contraptions, but I'm a bit at a loss as to how the teeth should be cut. None of the pictures I can find online are very clear, though I did find one video showing the thing being used in a bow-drill set up.

Are these things predominantly used by hand, or is the bow-drill method preferred? If the bit is rotating back and forth, it would seem like it won't cut on one of the strokes. Is that the point? Is it burnishing on the back-stroke?

Am I overthinking this?

 

[Wayland]

You stick the long bit in the middle where you want your dot to be and then twist the awl by hand around the dot.

Just like using an old school compass.

 

[tombear]

Since I made the two I use from spare/knackered Yankee screwdriver bitts I just use them in that sort of screw driver, or on occasion in a cordless drill. Seams to work fine. By hand is fine as well and more in keeping with their historical use. I tend to make a decent hole with a bradawl or similar first to avoid slippage .

come to think of it I've a old Archemedies drill that I never use I could mount them in, that would probably give me the most precise control.

I filed the teeth on one sloping back to cut in opposite directions, to cut mainly in one direction of rotation, like the one in the picture and the other straight across and to be honest they both seam to work as well as each other in a Yankee screw driver.

Now I'm over thinking it!

ATB

Tom

 

[VaughnT]

Sounds like I'll get to do some experimentation!

I really enjoy learning new things, and these augers are about as new to me as you can get. I'm sure there'll be some fits at the start, but overcoming the obstacles is half the fun.

 

[Whittler Kev]

Can't quite see it as you said. Anyone got any better pics?

 

[tombear]

Here's the thread with the two I've cobbled together

http://www.bushcraftuk.com/forum/showthread.php?t=118531

Not the best pics I'm afraid but you can just about tell the first one is handed to work best in one direction the second to cut so so but in both directions as in a Yankee or bow drill. I'm pleased with the results from both. Perhaps if I was using them on wood they would need to be sharper to leave clean cuts but for bone it doesn't sem to matter so much.

ATB

Tom

 

[Macaroon]

These pictures might help;

https://www.etsy.com/listing/237720143/4-5-and-8-9mm-diameter-ring-and-dot

 

[Macaroon]

Here's another;

http://www.bladesmithsforum.com/index.php?showtopic=25985

 

[Whittler Kev]

Here's another;

http://www.bladesmithsforum.com/index.php?showtopic=25985

These pictures might help;

https://www.etsy.com/listing/237720143/4-5-and-8-9mm-diameter-ring-and-dot

Got it. Look pretty simple to grind and I can see what they're for now