The Home Machinist!

A friend owns a steel company and is looking for something to drill holes in steel.

While They have large structural stuff on which it would be more appropriate to use a magnetic drill, we have a Bridgeport for sale locally that has some rust on it and needs a good cleaning. Even if the accuracy is compromised by a couple of thou, that's probably fine for what he does.

It goes down to 80 rpm in back gear, and if I remember, the J head has a downfeed, so he could run it without having to babysit it. I looked up some speeds for large hole saws and at 80 rpm in mild steel you could run a 3" hole saw.

Would this be an appropriate machine for his use?

Steve

I’m not sure I wouldn’t baby sit it...

You aren't supposed to use those head feeds for much over a 3/8ths drill size. The internals aren't built for that use and those feeds are really only meant for single point boring. Apparently even drilling one hole too large and some of the internal gearing will shear there teeth off in the drive.

What Pete said. A BP is a poor compromise for a drill press unless small drills are involved. One of the (very real) problems is how do you grip the drills? Large drills typically have tapered shanks.

My recommendation? Tell him to explore radial drill presses. They're built to drill large holes and are powered accordingly.

H

OK, thanks guys.

Oh, and if anyone wants to buy this Bridgeport, contact me via PM.

It's located near Bridgeport (yes, it hasn't traveled very far from the place of its birth).

We are still working on prices (I'm helping to liquidate a machine shop).

Steve

SteveM wrote: ↑Fri Mar 15, 2019 8:26 am OK, thanks guys.

Oh, and if anyone wants to buy this Bridgeport, contact me via PM.

It's located near Bridgeport (yes, it hasn't traveled very far from the place of its birth).

We are still working on prices (I'm helping to liquidate a machine shop).

Steve

Man! Trying to sell a rusty bridgeport after the discussion about the rusty lathe a few days ago? LOL I wish it was closer. I'd like to have one.

Dave

Meanwhile, for the home shop, it would be a killer drill press. And not much fun to move.

I've seen at least two BP heads made into drill presses posted on Craigslist over the years. Not sure how well it works out though.

That's not necessarily true about the innards being for 3/8 holes only my friend wood regularly drills with a carbide tipped drill 3/4" cast iron buns 7/8 stainless steel bongs by the thousands and no pilot hole and still going strong

The Bridgeport M head with the MT#2 taper is fine.

ERIE S-1 BERKSHIRES wrote: ↑Fri Mar 15, 2019 9:53 pm That's not necessarily true about the innards being for 3/8 holes only my friend wood regularly drills with a carbide tipped drill 3/4" cast iron buns 7/8 stainless steel bongs by the thousands and no pilot hole and still going strong

Not according to the factory manual. It distinctly mentions that power feed should not be used beyond 3/8" diameter for drilling. If your friend is hand feeding, that's not an issue.

H

SteveM wrote: ↑Fri Mar 15, 2019 8:26 am OK, thanks guys.

Oh, and if anyone wants to buy this Bridgeport, contact me via PM.

It's located near Bridgeport (yes, it hasn't traveled very far from the place of its birth).

We are still working on prices (I'm helping to liquidate a machine shop).

Steve

If you are helping to sell a machine shop, then have them buy a radial drill press if the shop has one available.

Richard W