"Robin S." wrote in message
news

"Harold and Susan Vordos" wrote in message
...

snip--


Harold,

Do you find you have issues with drills being pulled into the work when
double drilling? Working in a tool shop, we have no need for holes within
a
thou or two (either rough drilled or reamed only) so I don't have to do it
very often at all. When I do, I find the drill frequently pulls into the
hole making for a broken drill bit, spun part, or both. We have gear feeds
on our radials at work so it's not necessarily an issue for us, but HSM's
rarely have that luxury.

Regards,

Robin


Not in drilling most anything but brass. Keep in mind that I drill this
way routinely, so I probably subconsciously approach if from the position of
already knowing of the problems you speak of, which are very real. Fact
is, I should have made mention of them, but it didn't come to mind.

I rarely, if ever, use a drill press. I drill with my Bridgeport, almost
never without using the vise or clamping my parts to the table directly.
The control of the quill is superior to that of a drill press (radial drill
excepted), so I can feel what's happening far better. It's quite easy to
avoid hogging.

You raised some good points that should be of concern for those that use the
double drilling system, for which they should be grateful. It yields
better results, but has its own problems, as you've pointed out.

When I was trained (missile facility), hole size was routinely inspected,
and parts scrapped when oversized holes were created, so I was instructed to
work such that size was more or less guaranteed. I can see that where
one trains can be instrumental in what method is preferred.

Harold