Buying a Bridgeport: Advice

Well after many weeks of browsing the forum, doing some research and keeping an eye on eBay/CL, I'm finally ready to get a new mill for my business. I'm in the process of getting my 07FFL and sold my old bench top import milling machine a little while ago to upgrade. No matter how often I see them in use and hear of deals on the mill/drill combos and smaller enco, grizzly, jet and other models I keep coming up with the same result: Go Bridgeport or go home. So, I've found a few used Bridgeport 9x36 type models that would suit my shop well in the $1,500 dollar range. Ideally I hope to get the best bang for my buck without going over $2,000. That eliminates most of the 9x42 sized mills. My question is: Is there anything in particular that is a problem area or not desirable on the 9x36 Bridgeports (most I've seen are 1HP 3PH) that would make a 9x42 preferable OTHER than table size and HP? Are they all going to use the R8 collets? Is it possible to put a one-shot lube system on these in the same manner as the larger type? Other than table wobble and slack in the hand wheels is there anything specific to the smaller tables I need to be weary of? Thanks for all the great info provided on the site, much obliged.

While I have a Bridgeport, I would not feel the least under-milled with a Lagun. They are a little taller than a Bridgeport which might be a problem but otherwise, they seem to be tough and well made.

Lagun

Another vote for Lagun. I have the FT-2 10X50. Look at the FT1 series. Solid!

HKcarbine

I have had a 9x36, 1hp, J-head since 1995. Over the years since I have added 3 -axis DRO, X and Z axis Power feeds, VFD, Power Drawbar. It came with One-Shot lube. The most valuable accessories are the DRO and VFD. You can do without the others, but they really are nice to have. The VFD is the most important. It solves the single-phase to 3-phase conversion problem and eliminates the belt shifting for speed change. I have my belt set to give about 2250 RPM @ 120 Hz on the motor. Minimum speed is 185 RPM (10 Hz) I have never moved the belt. The VFD control panel has a JOG button which I use for power tapping, very convenient.

You can't flute a rifle barrel with a 36" table, but I have never needed to. Otherwise, I never felt the table size was a problem. R8 is by far the most versatile spindle system.

RWO

One shot lube can be fitted easily.

Many shorter tables are more evenly worn due to normal use, needing most of the travel all the time...

If it has a J head R8 taper you will be fine.. For a lot of gunsmithing work, even a M Head (#2 Morse, #7 B&S etc) with a VFD, would do much better than a round ram Mill Drill..

M Head limits you to around 1/2 in tooling.. Much gunsmithing work is done with 3/8 in ....

I find even my 32 in table, rarely causes problems for run of the Mill work.

I do have a bigger machine, but that usually does bigger than .50 caliber work...

I would get a VFD and then a DRO before a one shot lube system... It takes just a few seconds to wipe down dovetail ways and lube them....

One shot metering jets easily get clogged, then no lube at all until....

If it´s a hobby machine buy whatever you find and like. If you have to earn money with it get in touch with sidecar580 and buy a refurbished Bridgeport from him. It comes rescraped, checked and straight with a fresh coat of paint.

Cheers,
Johann

A 07 FFL is a Firearms manufacturing License.. A little step over a normal home shop.. Taxes, inspections, etc...

I've had to use a lot of mills over the years. Bridgeports, Kernseys, Cincinnaties, Laguns, Die Fongs ETC and I've never had issues with any of them. Even the Chinese ones. Learn to think beyond your needs though.
DROs are almost a must have on mills after you have used them. They eliminate the need to think in table slap or use dial indicators.
Fluting is becoming more and more popular as well as octagon tapering and if you feel you might like to do that then a 36 inch table is out of the question. You have to think in a foot for your dividing head and probably 9 inches for a tail stock plus 3 inches on either end for water traps. Add 24 inches of barrel and you need a 50 inch table.
Power feed is a must have for fluting or any long cuts and a lot of mills can't be upgraded to that.
Powered water can be added but its always cheaper to buy a machine with water. If you plan on using any HSS steal at all for drilling or milling you MUST HAVE A FLOOD OF WATER. Squirting WD40 on the cutter like I saw the other night on Sons-of-Guns is laughable and adds no measure of cooling!
I'm also not fond of fighting with draw bars in R8 spindles and R8s have limit tool size. There is however nothing stopping you from getting an R8 to ER40 collet chuck. ER collets are so cheep these days and I think they go right up to 1 3/16 inch. In fact if I ever set another lathe up for collets it will be for ER40s rather than C5s. That way you can have one complete set of collets for both machines.
Also consider your power requirements. Since CNCs became popular there is a glut of wonderful knee mills coming on the market. Most of them are three phase power. They may lull you into a false sense of security with phase converters but that's never as easy as the salesman says or as cheep. If you pay an electrician to install it you are looking at $1000.00 for a single machine or close to $2000 for a hub unit that will run several machines.
I am forever telling people to think things through. Build it twice as strong as you require or buy twice the size you need. No one ever listens but I do keep saying it.

A VFD can be a phase convertor... Many models convert single to 3 phase..
2 hp ~$230.00 and 3 pounds shipping weight.

Fluting can be nicely done on a Horizontal mill, No flimsy R8 Spindle/tooling. Spiral fluting is easy to do with a universal table horizontal..

Big old Horizontals sell pretty cheap now....

To me, fluting is a waste of time... And many of the firearms I work on, get the barrels up to 500 degrees or so... time after time... Octagon barrels also a time waster... Depends on what kind of firearms OP wants to manufacture..

I'm betting NOT single shots, or bolt, or lever guns...

The BP while not perfect, is handy and about the right size for much gun work..

Carving an action out from solid, is more in the realm of CNC machines nowadays. A R8 spindle BP can do it, but it's not going to make you any money.

Just a side note, if the screw feed slack is an issue there are threads on here and also kits available on converting from a lead screw to ball screw...no play, instant move...life is good.

DRO is a must have, I have seen from 5 tenth down to 2 tenth resolution.

At the very least, power X is also high up on the list. Cranking the table stop to stop tramming or indicating a long piece gets old...quickly. Plus it is much much easier to get a nice clean finish.

R8 collets go to 1-1/8" size, from what I gather this is probably more than large enough for your needs.

Ballscrews vs acme on a lightweight mill, has been talked about a lot here on this site..

Not for me... I climb mill a lot, and do not need a customers part ruined because my hand slipped off of crank. Cranking down gibs for friction = wearing out dovetails/gibs

2 tenths resolution does not mean accuracy. Milling on a R8 BP is more of a roughing operation at the tenths level. Just too much flex.

Most BP's after some use, end up with a slightly bowed up table... Tramming stop to stop, serves no purpose unless work runs full length of table..

A power feed is on my mill, but gets approx 10% use vs rest of machine.

VFD gets used every start up, DRO about 75% of the time.

Coolant hardly needed with average cut being < 2 inches long and .250 deep. Firearms are just not that big... Hogging an action/barrel blank out from solid, bring out the hose...

abarnsley said:

Ballscrews vs acme on a lightweight mill, has been talked about a lot here on this site..

Not for me... I climb mill a lot, and do not need a customers part ruined because my hand slipped off of crank. Cranking down gibs for friction = wearing out dovetails/gibs

2 tenths resolution does not mean accuracy. Milling on a R8 BP is more of a roughing operation at the tenths level. Just too much flex.

Click to expand...

Today I took 2 pieces of aluminum to within 5 tenths of intended size, with the same measurement on both pieces on my digicals...(if you would like I will check them on my digimics tomorrow .00005 res) on a standard leadscrew bridgeport that is probably older than me (30)...3/4" 2 flute hss endmill, and used the power feed...its probably well under a 62 rA finish on all sides.

1) Ballscrews make climbing much much easier on a bridgeport as there is little room for that screw to slack off
2) On a bridgeport you should conventional mill the bulk and climb your finish pass anyway
3) Proper clamping and fixturing can produce highly accurate AND repeatable results

Well now abarnsley. If some one offered you $200 to flute or octagon taper a barrel, would you tell him it's a waste of your time and turn him about face and hustle him out the door? Or would you look him dead in the eye and say "whatever you want buddy" and take his money? Just a hypothetical question of course. $200 does buy a lot of new toys dontchaknow! he he he
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Thanks for all the input and advice gents. Lots to consider. While I was not initially looking for DRO, VFD and power feed I did have those in mind as things to add in the future. My old benchtop mill was all manual so they'd be luxuries compared to what I had been operating on and do want them at some point. As for use, I have no plans to offer fluting services on barrels but I can see how you'd need a massive table to do this. I suppose if you're talking a 16 or 20 inch length barrel if you table has this much travel in it then it's doable; but lots of my past work and potential customers are "AR based" and such parts are plentiful and priced decent enough. Initially, as this is a part time endeavor for the time being; I'll be sticking with what I'm good at and that's full refinishing/parkerizing, AK variants built to order, semi-auto MG re-welds and of course AR15 work. So I'm thinking a 9x36 would serve well enough. I am digging the info I've been finding on the VFD units, way more appealing than a phase converter and step pulleys.

9 x 36 BP
Ok, this is the smallest size and yes there is a bit to look out for.

1) round ram - the very oldest machines have a round ram rather than the cast iron dovetailed configuration used later. They are harder to tram and the ones I have encountered lack the nuckle joint behind the head.

2) M heads, some of the small machines were equiped with a smaller (M series, rather than J series head). M heads use morse taper collets and wont hold mills larger than about 1/2 inch.

3) BP mills are very common machines. Its not uncommon to find one cobbled together from several mills. Putting a good, new head on an old knee is a nice way to upgrade from from a J1 to J2 series head. Serial number lists can be found on line, and armed with that information you can spot significant age differences.

4) J1 heads have a step pulley- no problem if you use a VFD and do light work. J2 heads have a variable speed pulley system, so torque increases as speed drops and vise versa. You dont get that with a VFD.

5) Second hand DRO's, power feeds and one shot oilers usualy dont comand much of a premiumu on used machines, but are very pricy to add later. Hold out for a machine that has at least one power feed. A machine with a 1 shot oiler is more likely to have been properly lubricated, and a DRO is just very nice.

6) try to confirm that the borring feed system in the head works. Getting a good surface finish with a boring head without power feeds is a chalenge.

7) Open the door on the side of the column. Some machines are equiped with collant pumps, some are not. Its also not uncommon to find some forgotten treasures in their.

8) Avoid machines with holes drilled and tapped in the tables. This was probably done for a production fixture and the machine is likely to have heavily worn areas.

9) Pay for a good knee, some are worn, dished and loose, others are tight. Look closely at the ware patterns, and buy the tightest knee you can find and afford. Its a lot easier to rebuild the head than refurbish a knee.

10) Occasionaly you find a machine with a riser block to elevate the head 3 to 9 inches. It fits in the swivel joint between the column and head pivot joint. The riser allows more room between the head and table for larger parts. This can be very nice if you do a lot of work in a vise or are tall and just like the table to be a little higher. To much riser and you cant get the quill all the way down to the table. This can be a problem for short parts clamped driectly to the table.

11) Series1 and Series 2 BP, some changes to knee size were made and the hardness of the knee may be different. A little background work on the BP forum is warrented. I am not sure how the changes affected small table machines. You might find a cobbled together machine with the best of all worlds. If you do, buy a few lottery tickets.

@ ahall: Thanks for the tips, I will keep this in mind. I had not taken into consideration the J vs. M head, I will look for that. The 9x36 machines I've seen so far online are very spartan with no VFD, DRO or one shot lube system. A few had at least X axis power feed, some X/Y but that's about it. I sent sidecar580 to see what he had refurb wise but no word yet. I'm starting to have the opinion finding a mill to fit me is far more difficult than the federal licensing. Just have to keep waiting it out for one to pop up.

I do much the same type work as sgt5h plans to, only repairs, not manufacturing..

I do help out several local manufactuers...

A 9 x 36 R8 J head BP, in not too clapped out of shape, will work fine for his desired work..

I do it for a living....

I send most bolt gun rebarrel work out to other local smiths, I specialise in things Canadians can't shoot, load magazine to full original capacity, or travel to the range with..

Blueing and parkerizing is sent out also, sure I could make money... But it is MESSY and would do bad things to the machines in my shop...

Just not much call for fluting or octagon barrels in my shop..... So I don't tool up for it.. Done to extreme, it actually produces lobes/uneveness in the bore, unless bore is drilled after OD machining.

Amen to the bluing !!!!!!!!!! I did it for 25 years but when I set up this shop I said NO MORE BLUING ! EVER !! I did however cheat a bit when I did do it. I ran the tanks outside in garden sheds and the last setup I used was in a shipping container so it wasn't an issue with steaming up the shop. Its not that its hard work either or all that messy, if its done outside. Its more of a money issue than anything. Everyone whines about the price because there is always some goof doing it in his garage once a year for $50. If he ever gets around to running a batch. I think I had about 4 guys in a row that called me a F****** crook if I thought they were going to pay that much to reblue a gun and I finally said "FINE, YOU DON'T LIKE IT ? NO MORE BLUING !" I still get a dozen calls a month for it but I won't even entertain it now. I very seldom ever get mad but when I do toss a tantrum, it sticks for a mighty long time. LOL

"How much to reblue my rifle?"

"$125."

"That's ridiculous!! Fred Jones does it for $50."

"Then take it to Fred Jones. It's $125 if I do it."

I used to charge a hell of a lot more than $125.00 GGaskill. I'm no SMALL TIME CROOK. I actually do pay my rent. LMAO I often wanted to find the mythical (Fred Jones) and farm all of my bluing out to him for $50.00 a gun. Most of the time he was as elusive as the USA 4th of July Commemorative 3 dollar bill. The odd time that I did run down old Fred, he only cold blued, or the last time he had fired the salts was in 1947. If I ever set up tanks again it would be strictly for my own use and there would be NO commercial bluing. And I'd keep it tighter than the location of Ole Mizz Magrets corn likker still and her son Ed-Earls marijuana crop.

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