"DoN. Nichols" wrote in message
...

Hmm ... about 39 SFM. What was the material you are drilling?
And was it hardened steel or mild?

A mystery metal which I was probably wrongly lead to believe was mild steel.

An identical drill from the same vendor has no difficulty drilling into
steel
otherwise.

The *same* steel?

A different one.

I cannot understand why this is happening given the solid nature of
clamping
and
all the other factors.

Note that the clamping may not be that solid. You are sure that
the ends of the cylinder are parallel -- but the jaws of the vise may
not be.

A quick-and-dirty way to get more grip is to put some cardboard
(not the corrugated stuff -- what used to come in shirts from the
laundry) between the workpiece and the moving jaw, leaving the fixed jaw
to define the position of the workpiece.

Ah! That is useful...Thanks.

Oh yes -- and the 3/16" drill bit is quite flexible too. A
screw machine length drill bit would be shorter and thus less flexible.

Yes, that appears to be the consensus.

And who made the drill bit? If Chinese, it is a pure guess as
to how good a steel is in the drill bit. If a US manufacturer like
Cleveland, you are going to be more certain of the quality of the steel,
and if you need it, you can go to a cobalt steel which is tougher (and
more expensive).

I cannot imagine that Canadian Tire sells anything but Chinese. They look
pretty though...

I cannot see where flex would occur to produce the
extreme form of chatter and subsequent rubbing (which is surely where the
smoke
and welding effects come from).

Can you identify what was shaking relative to what? In a drill
press, there is flex in the column itself, the mounting of the table to
the column, the mounting of the vise to the table, and usually the fit
of the quill in the headstock casting.

In the end everything was shaking including myself. It is worth noting that
I had a similar experience with a similar shape in my mini-mill but the
details are now obscure, especially the nature of the metal.

Was the vise firmly bolted to the drill press table?

I should remember but I do not. Somehow I think it was as I would normally
clamp this sort of work but I do not always bolt the vise for a
straightforward small hole. This, of course, was not it.

A milling machine is typically more rigid.

And some floor standing drill presses may as well be made of
freshly cooked noodles. :-)

It is what it is. Bridgeport it ain't.

snip

The experiment is to be repeated with some changes and bona fide mild steel.

--
Michael Koblic
Campbell River, BC