s and d bits

[bregolad]

I've been digging for some posts on silver and deming bits, but i can't find any. i just bought a set and i'd like to reshape them. is there a good way to do this, or some resource you can point me towards?

[ToddJohnson]

I've been digging for some posts on silver and deming bits, but i can't find any. i just bought a set and i'd like to reshape them. is there a good way to do this, or some resource you can point me towards?

I reshape them on my bench grinder and profile them by hand. I honestly have no way of knowing whether this is simple or difficult, but for me it only takes about five minutes per bit. What I do is use the side of the grinding wheel just like I would use the face of my shaping wheel. Then once I've ground it to the profile I want, I actually put the cutting edge on it using the "edge" of the grinding wheel (the part you would normally use to profile something). Mine cut with zero chatter and they remove perfect paper thin curls--no squeaking or squealing. They're cheap Chinese bits, too. I don't really drill with S & D bits much, so it's not worth spending $80 a piece on American made ones when you're going to profile them yourself anyway. In terms of procedure, it's a lot like shaping a pipe on the wheel--balance, symmetry, precision, etc.

TJ

[DMI]

I have just bought half a dozen old bits to practice on, I intend to use the lathe&grinder method then 'polish' the bits using emery cloth. I'm most interested in seeing how a dublin bit works, getting the edge sharp all the way up should be fun.

Todd, is it best to leave the bit full length or shorten it for stability?

David.

[KurtHuhn]

There's a thread somewhere on here about how I reshape S&D bits, but I can't find it presently. Like Todd, I use cheap Chinese bits, and have zero problem with them scary sharp. I use a different method though - I mount them in my lathe and profile them using an angle grinder, then clean them up by hand providing a slight relief angle behind the cutting edge using the bench grinder - similarly to the way I think Todd described.

There's also another method that involves mounting the bit in a drill and spinning it while re-profiling it with a bench grinder, but I have not tried that.

In the end, the cheap Chinese bits are very well suited to this.

[TRS]

There's also another method that involves mounting the bit in a drill and spinning it while re-profiling it with a bench grinder, but I have not tried that.

In the end, the cheap Chinese bits are very well suited to this.

I've done this, with these, and it worked quite well. Can't beat reshaped spade bits though, imo.

[ToddJohnson]

Can't beat reshaped spade bits though, imo.

I know guys who like them--Jody for instance--but I'd resort to flint-knapping before drilling with a spade bit. Even with a 2 1/2" shank they always seem to squeal and wobble. The damn things just make me nervous. I like for things to feel solid, and spade bits just never have. That said, they're probably a lot easier, cheaper, and more accessible for guys who are just starting out.

TJ

[TRS]

I know guys who like them--Jody for instance--but I'd resort to flint-knapping before drilling with a spade bit. Even with a 2 1/2" shank they always seem to squeal and wobble. The damn things just make me nervous. I like for things to feel solid, and spade bits just never have. That said, they're probably a lot easier, cheaper, and more accessible for guys who are just starting out.

TJ

What do you usually use, spoon bits?

[ToddJohnson]

I know guys who like them--Jody for instance--but I'd resort to flint-knapping before drilling with a spade bit. Even with a 2 1/2" shank they always seem to squeal and wobble. The damn things just make me nervous. I like for things to feel solid, and spade bits just never have. That said, they're probably a lot easier, cheaper, and more accessible for guys who are just starting out.

TJ

What do you usually use, spoon bits?

Mostly, yeah.

TJ

[Sasquatch]

In the nineteen sixties, we developed a sophisticated heat beam called a "laser"....

[bregolad]

thank you muchly, fair gentles. methinks i got it