I Want A Bridgeport Mill

[BigAL]

So what do I need to know, what are the best models to buy used, what do I need to look out for, what's the deal with the "J" head, what is "true trace"? I'm pretty much green to these things, so any info would be much appreciated.

[studemax]

Unless you are buying a used Bridgeport, be prepared to spend tall stacks of long green.
Then after you get the mill, you need a set of R8 collets, a clamp set, and a bunch of end mills, a drill chuck, etc.
I'm talking cubic money.

[squirrel]

Oh, it's not that bad. Make sure the moving parts are in good condition, etc. The tooling is available new pretty reasonable, if you buy the chinese versions. The mills are mostly all 3 phase, but you can get a Variable Frequency Drive that is designed to run on 240v single phase and make 3 phase from it, and it can also control the speed and direction of the motor with a little bit of programming and some control parts (a potentiometer, and a couple switches).

getting the machine into your shop can be fun, also they are kind of tall, so 8 ft ceiling is needed minimum, 10 would be nice.

I picked up an old Taiwan copy of a Bridgeport for a grand earlier this year, I finally got it moved into place, still haven't wired it up yet...one of these days...

[tardis454]

So what do I need to know, what are the best models to buy used, what do I need to look out for, what's the deal with the "J" head, what is "true trace"? I'm pretty much green to these things, so any info would be much appreciated.

* J-head (J1) Bridgeports use R8 collets. A True Trace is a hydraulic tracer attachment that follows a profile or pattern like a tracer lathe. (you won't need it)

* The early Bridgeports were M-heads. M-heads used 2M (#2 Morse taper), or 7B&S (#7 Brown & Sharpe) collets which are hard to find. (older than dirt, hens teeth)

* J2-head Bridgeports have Vari-drive. Instead of swapping belts like a J1 or M-head, you crank handle to increase/decrease spindle speed. (kinda like a snowmobile clutch)

As far as the best model to buy, a J2-head would be ideal, but J1-heads tend to be cheaper and are plentiful.

Try to find a Bridgeport that was used in a tool room. Tool room machines generally have less miles on them.

Mills used for production work get the shit beat out of them. The gibs, ways, spindle bearings, and knee/table screws get worn out.

Some of the knock off Bridgeports are ok. Jet makes a pretty good machine. My buddy bought one for his shop for tool room duties.

I worked at a shop in the 90's that did machine rebuilding. I learned a lot about lathes, mills, and screw machines working at that shop.
Let me know when you wanna buy an engine lathe, I know a lot about those too..

[DanStokes]

Me too, Big Al, me too.

Dan

[Beagle]

Slab thick enough for machine weight without vibrating? They're not light.

[Barry Donovan]

I am subscribed to some machinist channels, those mills are very handy.

here is a good search result from you tube:

https://www.youtube.com/results?search_query=bridgeport+mill

the modern addons are very dynamical. I think "fiatnutz" did something all computer with his, or got a whole new one or something. veyr modernized. The real careers spend the real dollars.

just a carbide anything of the real kind is big bucks.

[Beagle]

I don't wanna be that guy who says "why don't you just"... Just thinking out loud here and don't mean to step on any toes or hurt your feelings, but I have a couple of questions. Other than being able to say "I have a Bridgeport" which sounds cool and all that, what are you planning to do with it? How big are the parts you plan on working on? Squirrel made some replies to me in his thread a while back and what I got from those replies is that they aren't really big enough to do block work on, and not really big enough (steady enough) to do things like head surfacing with the degree of precision things like heads and blocks require. Those things are best left to big hairy expensive heavy dedicated machines is what I took away from his comments, although I've been known to misinterpret. It sort of killed my desire for a big mill.

If you're gonna goof around with small stuff that doesn't necessarily need a garage consuming behemoth or require .0000x repeatability, you might have a look at some of the smaller benchtop mills with either a simple DRO or even full on CNC and get a good indexing head.

anyway, thought I'd throw that out for consideration. Good luck on your purchase. Sorry about your bank account when you start buying tooling.

[Loren]

Dirt cheap: https://phoenix.craigslist.org/wvl/tls/5259129759.html If it's your first one you won't mind it being a beater, it will still be amazing, just make sure it runs or have a written contract that it does. Try to get something w/ vise and as much tooling as possible included. Yep, most will be 3 phase...it's most practical to just get the converter then you'll be set for you next machine too.

[squirrel]

that's pretty much what I got. I'd hold out for a real Bridgeport, if I lived in a big city like Al does.

[Loren]

For 2k: https://phoenix.craigslist.org/evl/tls/5256722740.html

[Beagle]

For 2k: https://phoenix.craigslist.org/evl/tls/5256722740.html

I don't know Loren, looks like a pretty big machine to drive with a bicycle crank.

[Loren]

Well you need a second person to do the pedaling. Maybe it's like a 220 single phase...you only need two legs, and the ground...

[DanStokes]

Pretty clever, Loren - pretty clever. Sounds like something Gail would come up with (OMG - there's 2 of you in the same house!).

Dan

[BigAL]

Dammit Loren, I got to wait at least a couple months for the little lady to forget about my last big purchase.

And Jim you're right, I want to hold out for a Bridgeport.