New Hardinge BB4 Mill, Fixer upper, couple questions?

Hi Everyone,

I've been lurking for a bit, trying to read as much as I could before posting.

I picked up a little BB4 mill at a local scrap yard type place earlier this summer.
Other than loosing half the paint on the drive home it's been in pretty decent shape as I've been cleaning it up.

The only downside has been it was modified to use an air-hydraulic feed on the X axis.
Now that winter has settled in I've got some time to attack that part.

My assumption is that replacement screws and nuts are pretty rare, and if they are like other Hardinge machines the nuts were cut in place anyway.
Unfortunately, while the old nut is still present, it was bored out and threaded for the actuator.

My current plan of attack is to make a replacement ACME screw and nut.
I know the old screws were square thread, other than originality is there a functional reason not to use an ACME screw instead?

Also I found a listing for a cataract compound screw assembly, while the screw seems much too short. It looks like the mounting plate that screws into the end of the table with half of the dial assembly is the same. Any idea if it would fit?

The other part that's been bugging me, the headstock has only one oil cup, the one in the front. Everything I've read indicates it should have 2. In the process of cleaning it up I removed most of the old pealing paint and couldn't find a hole where one should be. Any thoughts?

Sorry for the lack of photos, I left the camera at the shop and haven't gotten a chance to run back for it yet.

Thanks for any advise you might have.

No replies? Try over on the Antique Machinery and History forum.

I rebuilt the headstock of a BB4 last summer and they have two oil cups originally. It may be someone put a different headstock on yours. A lot of the later lathe headstocks only had the oil cup in the front. That's actually nice since it indicates you probably have a sealed bearing in the rear instead of the awful open oiled setup with the cork seals. A lot of the Hardinge split bed lathe headstocks will fit on a BB4 base. When you post pics, we can tell.

As far as square vs ACME threads on the feed screw, one is as good as the other and I think Hardinge went to ACME later on anyway. Sticking to square is only for being "original". I don't know about the fit of the end plate.

Irby

Not sure what the BB4 is. I have a TMU I think that I modified for a lever/cable drive on X. If your is also a horizontal, maybe refreshing the air over hydraulic feed would be a more useful course. I know of someone looking for such an animal right now for short run screw slotting.

FredC said:

Not sure what the BB4 is. I have a TMU I think that I modified for a lever/cable drive on X. If your is also a horizontal, maybe refreshing the air over hydraulic feed would be a more useful course. I know of someone looking for such an animal right now for short run screw slotting.

Click to expand...

The Hardinge BB4 is a bench horizontal mill that takes 4C collets. The original headstock has a 3.5" center height and the spindle nose is a plain cylinder with no jaw chuck mounting provision. The table is about 12" x 3" wide. The original table feed screws are 7/16-10 LH and RH and taps are quite rare, whether the original square or acme. I don't know if a 1/2-10 acme will fit in the castings. My BB4 was built in 1946 and is on a steel cabinet.

I have not had time to see if a slide rest feed screw bracket will fit the mill table. I will warn that there are 7" and 9" swing lathe slide rests that look alike, but have different dimensions.

Brochure pictures below, along with a set of feed screws and nuts.

There is no TMU model. FredC might have a TM (plain) or a UM (universal, with swivelling table).

Larry

Sub'd to this thread. That is a really cool little machine. I'm looking for something similar (FredC mentioned above) To the OP, hoping you'll add some pictures of the machine.

Best,

CE

Larry is right on the larger machine, mine is a UM, the older I get the harder to keep all the nomenclature right.
That BB4 is a cute little thing. Finding it in a scrap yard is something! People can not recognize good stuff anymore.

Sorry for the delayed response. What I thought was going to be a quiet week before the holiday...
Thanks for all the info and suggestions!

I've attached a couple pics of the mill. Not the best paint job I've ever done, but it got the pealing paint and layers of grease off.
Other than a few dings on the table it seems to be in decent shape. Seems like it was in-use until it was sent away. Grease on the motor bearings is pretty fresh looking

The place it came from gets tools and machines as well, they pack them in 40' containers in the back of the lot. Was surprised when I ran into this guy.

Fred- you may be right on using the air over hydraulic system, I kept all the parts.
The plan is to set this up to cut small gears in mostly brass, and delrin. Power feed would come in handy there.
Wanted to get the screw feed setup to play around with some scrap and see what this little guy can do.

Irby- It hadn't occurred that someone may have swapped the head along the way. Does take 4C collets, and is 3.5" center height.
Unfortunately the panel that normally has the serial number, was removed and replaced with a bulkhead for the air fittings.

They had 2 more of them, one had a busted knee. I was thinking about buying that one, using the stand for another machine, and looking for a bed for the head stock.
Went back around Thanksgiving, they had an auction and all that stuff got cleaned out.

Larry - Thanks for the info. The photo of the feed screws is quite helpful. The seller of the lathe part was able to confirm a couple dimensions, it seemed close enough to take a gamble given the price.

-Greg

Very nice! I restored one a few years ago, just now put it up for sale.

Yeah, you should have brought home all they had at that scrap yard.