Benchtop Bridgeport - what would you do?

[cederholm]

Lots of great advice everyone, I appreciate all the input.

Dave mentions that the M style head might not be the best - can you guys enlighten me about the M style and some of the other Bridgeport heads?

Yes as stated, it’s a Bridgeport M head stuck on a little drill press base…interesting. If you are looking for just one milling machine. The “M” style head is not really the best choice. And if you want a Bridgeport, then probably a Series I with a J head would be the one. Maybe sell what you have and use that $ to help fund a real mill…Good Luck, Dave.

 

[cederholm]

Dave, any perticuar reason that I should consider Atlas?

Thanks a bunch,
Carl

I would save it and if you find an atlas horizontal mill or other small horizontal mill you could use it for vertical convenience ----there also are good XY tables that could be mounted to the base----I saw a M head last year I offered $200 for but the owned wanted $450 and declined.---I have an atlas hor mill that I am converting to vertical ---hang onto it at least till you get a benchtop mill----use it for what it is---it is unique---Dave

 

[Dave Smith]

Lots of great advice everyone, I appreciate all the input.

Dave mentions that the M style head might not be the best - can you guys enlighten me about the M style and some of the other Bridgeport heads?

one thing the J head has better is it takes r8 collets and probably larger ---I'm not sure what the M head spindle takes---you could use yours with a crossslide rotary table and it would be very useful----search ebay for them --there are always some under $150

 

[Dave Smith]

Dave, any perticuar reason that I should consider Atlas?

Thanks a bunch,
Carl

Carl---I just thought I could have mounted it on my Atlas on the 1 1/2" support arm is why I made an offer on one--I think you could find a good cross-slide rotary table and just mount it on the lower base of your unit--usually with a rotary table you don't have to have much XY travel----Dave

 

[cederholm]

Thanks Dave, very helpful.

 

[Eddyde]

Carl, What kinds work do you intend to mill? If its relatively small hobby stuff than that mill drill set up with an XY table will do just fine. at least to start. For years the only milling capacity I had was just a drill press with a shop made XY table, it certainly wasn't the most capable setup but it could do a lot.

 

[cederholm]

Hi Eddyde,

Yes small hobby stuff. ...and to learn on. I have a lot to learn about machining.

Carl, What kinds work do you intend to mill? If its relatively small hobby stuff than that mill drill set up with an XY table will do just fine. at least to start. For years the only milling capacity I had was just a drill press with a shop made XY table, it certainly wasn't the most capable setup but it could do a lot.

 

[Holescreek]

The "M" or "Master Milling " head was the first head Bridgeport made. It is a great little milling head provided you don't want power feed for boring (it has a manual downfeed handwheel) and don't want to use a collet over 1/2" in diameter. M heads were made in 3 collet sizes with B&S#7 taper and M2 taper being the most common. Collets are sometimes hard to find and can be had in sizes up to 1/2". I used an M head exclusively for a few years and made my own end mill holders to accept up to 3/4" shanked end mills. The motor HP being limited at 1/2HP (or was it 3/4?) meant you had to be careful on deep cuts. My machine did amazing work but because I did a lot of boring I wanted the power downfeed spindle of a J head. I bought a J-head assembly and made an adapter to mount it to my M-head mill. I sold the M-head later on to someone that wanted to mount it on a horizontal mill.

 

[cederholm]

Great overview on the M head, thank you for that. And thank you all for the wealth of information.

I think my current plan is to clean up the machine, buy a power inverter to get it running and go from there. If it runs well and is mostly complete a table will be in the near future and I'll keep on eye out for a Bridgeport base or a horizontal mill.

On that note!!! Can anyone share a photo of a vertical/horizontal hybrid? Preferably a home-built unit.

Thanks all!
Carl

The "M" or "Master Milling " head was the first head Bridgeport made. It is a great little milling head provided you don't want power feed for boring (it has a manual downfeed handwheel) and don't want to use a collet over 1/2" in diameter. M heads were made in 3 collet sizes with B&S#7 taper and M2 taper being the most common. Collets are sometimes hard to find and can be had in sizes up to 1/2". I used an M head exclusively for a few years and made my own end mill holders to accept up to 3/4" shanked end mills. The motor HP being limited at 1/2HP (or was it 3/4?) meant you had to be careful on deep cuts. My machine did amazing work but because I did a lot of boring I wanted the power downfeed spindle of a J head. I bought a J-head assembly and made an adapter to mount it to my M-head mill. I sold the M-head later on to someone that wanted to mount it on a horizontal mill.

 

[franklynb]

Thanks for the input everyone. The machine was purchases in the late '80 for a Raytheon auction and I assumed it used for something special.

Currently I use my Maximat Compact (see pic below) for light duty milling/learning to mill. Do you think this Bridgeport would be capable of heavier duty milling? Heavier than then the Maximat that is.

Hate to be the "contrarian" :whiteflag: but someone should say it. And you asked: "what would I do?"....

If you have a maximat I'd expect the table and post for the M head to UNDERPERFORM what you already have!

There is no way you're going to transfer the ~1? HP of that head into that tiny table -- too little clamping; too little
stiffness in the 2-1/2"? post; and you take a chance of flipping that tiny split clamp table right around the post every time
you hit some hard spot in the material -- or mis-gauge your initial depth of cut guess!

It makes a nice quill for making counterbores/sinks. That's about it. Not enough post height to hold a standard drill and chuck.
My Van Norman #12 frequently drives me a little crazy hunting for Z room and it has almost 7 inches between spindle and table!
A 4" drill and ~2" chuck and adapter chew that up pretty quickly.

What good is a drill press where you have to dismount the part to get the drill out? Think about it!

So; trade it for a real drill press -- like a Delta 14" or 17" floor model -- making a nice combo with your Maximat. And "google
is your friend". A brief image search of 'cincinatti mill and bridgeport head' yields a fair amount of eye candy and info.
No need to copy those images here! And the linked pages hold lots of beginner info and places to start your search.

You will quickly come to the conclusion that there is a reason these heads are mounted to a beefy table; reasonably spaced
real "ways" and a stout column! This setup is of extremely limited use without these features. This is why people mash them
up with old universal mills -- cheap real iron tables of stout design premise to match the HP of the head.

You wouldn't enjoy a 350hp V-8 stuffed into an MG Midget. Same deal here. The basis is too flimsy to make the package
enjoyable. And if you're not doing this for the pure enjoyment .... nuff said.

I have two of that same drill press base and they cannot handle any side load to speak of. They're extremely useful with
the 1/4hp belt drive motor and ~2" stroke quill that came with. Don't waste your money on
an X-Y table -- only to discover its a dangerous idea as the part comes flying off with the table. Or the entire table cracks
off the post at the clamp!

--frankb