Evaluating a Bridgeport

I've been thinking of getting a mini-mill this Winter, but sometimes I wonder how an old Bridgeport might be evaluated as a possible
alternative. I hate the idea of hauling a bridgeport home (rent a big truck and a forklift?) but occasionally I see one in my local area. How would I evaluate one to decide if it is worn out junk? Or am I just better off with a mini? Thanks! http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item%78659871&category 586
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Several years ago I bought a like brand new Enco Mill-Drill. I can say I was actually fairly happy with this machine for doing smaller projects. They also work as a heavy duty drill press. I was then able to pick up a bridgeport (much like the one in your link) in decent condition. What a world of difference and with a digital readout installed on it that takes away alot of the "its wore out theory". If the bridgeport in your link is close enough for you to go inspect and its in good condition I would say for 1500.00 its a pretty good buy. You might also keep checking around for a Rockwell mill. They are smaller than a bridgeport and weight alittle less but are actually quite rigid machines. I have found that the bigger you can stand to buy it is generally going to be a better machine for less money. I picked up a Cincinnati 205-12 Cintiveral mill a year or so ago in need of some work quite reasonable. This machine makes a bridgeport look puny and its got powerfeeds in all directions. On the other hand where a bridgeport is in the 2000-3000 lbs range depending on type and style the 205-12 weights about 6000 lbs. While I can move just about all my equiptment myself I have found it just as easy to call a roll-off truck to do the extra heavy moves. The Cincinnati was a spur of the moment deal and a "had to get it out of here fast type thing", a quick call to the towing service and it was picked up and enroute to my home within 30 minutes. The cost was only about 50 bucks for the move.
tim
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this bridgeport seems to have a round ram which is less desirable it is not a good seller. try this site for info on looking for a mill http://www.mermac.com /
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galt snipped-for-privacy@hotmail.com (Dave) wrote:

Asp3211968 is correct.
The mill in the listing above appears to be made from two different machines. The head is cream colored, the base is blue.
The seller's description and his pictures are very poor. You just don't know what you are buying. Is that DRO part of the sale?
As for evaluating and moving a Bridgeport. Here are some things to consider:
Older M-head and J-head machines had a round ram. The newer J-head, 2J-head and Series 1 machines had a dovetail ram. M and J-head machines have pulleys that require manually changing speed. 2J and Series 1 machines have a variable speed adjustment on the front of the head. M-Heads usually accept #2MT collets everything else accepts an R8.
Backlash on the lead screws is always an issue with these machines. A "good" machine will have a backlash of about 0.030" or less. Do not be surprised to find a machine with a backlash of over 0.100".
While you are looking at the wear of the table. Grab the table and try to twist it (in the X-Y plane). The gibs on these machines will wear, you can frequently find as much as 1/4" of movement in the table by doing this. Now imagine trying to make a straight cut with a table that can twist to that degree!
The quill feed is frequently broken on these machines. Also the quill feed handle and wheel are frequently missing.
If the machine has a power feed on the table, ensure that it works. This is another item that is often broken.
A DRO is a real plus for a Bridgeport mill. Ensure that it is functional.
Rough current market pricing:
M-head in "good" condition: $600 J-Head: $1,400 2J: $2,200 Series 1: $3,000
Add for power feed $100 Add for DRO $150
Other things to consider: -Are the ways chromed? If so, add a couple of hundred bucks. -Is the table chromed? -What is the table length? Add a hundred bucks for a 48" table. -Are there any significant dings in the table (Significant dings will reduce the price by a couple of hundred bucks, but if you think about it they probably will not reduce the useability of the machine.) -Is there a riser in the machine. The eBay listing that you linked does have a riser. A riser will add a hundred bucks to the value.
If the machine is in mint condition, then you can increase the price by say 50%. If the machine is in poor condition, then decrease the price by 25% (Or better yet: just bypass it).
These machines weigh between 1,400 to 2,200 Lbs. All you need to move one is a Johnson bar, a pallet jack and a drop deck trailer. You don't necessarily need a fork truck. A drop deck trailer can be rented from Rental Max for $40. If you're moving it over 100 miles then it might be a good idea to rent a truck with a lift gate.
One last consideration: If power is an issue, you can occasionally find a Bridgeport with a 110 motor. However, more than likely it will have a 220 3-phase motor. Since you say that you are going to use it at home, you might want to get a phase converter, though it is possible to run it on 2 phase power.
Hope that helps, George.
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Hmm. Moving a full sized bridgeport with a pallet jack might get a *bit* interesting. I suppose you would use the johnson bar to lever it up a bit at a time, to allow the pump jack to slip underneath?
Then how to get pull the pallet jack onto the trailer, while it's got the full weight of the machine on it, and does one then reverse the process with the johnson bar to set the machine down for transport?
As you say, I suspect it would work - but not for more than just around the block or so.
Jim
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(Dave) wrote:

Thanks George (and everyone who has offered advice). I was just studying the photo and it looks to me like the table is chewed up. Who knows what else is wrong. At least they lowered the starting bid. I dread the idea of hauling this monster and then finding that it is worn out in 47 different ways.
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4 days into the auction and no bids tells you something. Let this one ride, see if there are any bids at all. If it doesn't sell, e-mail the seller and go have a look at it. If it is too far to go see, look around more local (regional). A newbie needs to see touch and feel the merchandise.
Dave wrote:

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wrote:

IIRC..the last round rams were made in the very early 1950s. It looks like the head has been replaced, so it indicates that there was a bit of usage on the machine.
It would be interesting for somone to reference the head serial number and find out when that head was made. Step Pulley S/N J4192
Id have to say..that the price is a couple hundred dollars high..maybe for a machine of that vintage.
Now the big question is..how much wear can you live with? If you are only going to be making small stuff, the gib can be snugged up a bit and it will be tight in less than the full travel due to wear in the center of the ways. Which is not necessarily a bad thing if you are making small stuff. If you are planning on fluting rifle barrels..this is NOT the machine for you. If you are only making stuff a foot long..then it might be.
Lets be honest..most of us make stuff that is less than a cubic foot 99.9% of the time and even a worn lathe with tightened gibs will work fine.
I have a customer who buys round ram machines when he can find them, simply because he likes the ram features for the parts that he does. And he buys them cheap, tightens the gibs, and cuts ceramics until they are no good any more, then scraps them.. shrug.
Its up to you..a loose but tightenable BP is still a better machine than a Mill Drill, assuming good bearings and equivelent backlash.
Gunner
No 220-pound thug can threaten the well-being or dignity of a 110-pound woman who has two pounds of iron to even things out. Is that evil? Is that wrong? People who object to weapons aren't abolishing violence, they're begging for the rule of brute force, when the biggest, strongest animals among men were always automatically "right". Guns end that, and social democracy is a hollow farce without an armed populace to make it work.         - L. Neil Smith
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Gunner wrote:

I think the last round rams were made in 1956. Bridgeport definitely made round rams with the J head for several years, I have a catalog picture of one. They did not have the full knuckle joint like the earlier M-head round ram machines, just a swivel so the head could tilt left/right.
You can look at the bottom of the table, and see how much of the frosting marks are worn off. If they are all gone in the middle of the table (like mine) you have maybe .003" wer in the middle. That is not good, but it could be OK for simple work.
Jon
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Are there distinct disadvantages to a round ram? If I seriously start looking at old BP's what do I need to bring? A flashlight? A steel straightedge and a feeler gauge? To seriously consider a BP I'd need to build a helluva dolly for it. I don't have smooth concrete everywhere. I'd need to be able to handle gravel.
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On 9 Dec 2003 05:18:52 -0800, galt snipped-for-privacy@hotmail.com (Dave) wrote:

They are not quite as rigid as a standard dovetail ram. A bit more flex. Probably something you will not notice doing HSM stuff..maybe.

Yes. A retired machinist is also a handy accessory. A Dial test indicator is also nice for checking the bed and ways. Put it on or in the spindle, touch the table, and crank it back and forth, to see if it droops too badly. Then simply lift and push and pull and pry to see how much play there is. a .001 indicator will be good enough.

Do like the rest of us do, buy a half dozen sheets of 3/4" or so, plywood, or even MDFand make a path out of the stuff. You can do it with two sheets even. Move the machine, move the second sheet forwards, move the machine, move the first sheet, repeat as necessary. I like to stick the second sheet under the first so it will not gap apart when you cross over to the next sheet, but it does make a bitty speed bump you have to watch out for. Just about EVERY machine in my home shop was moved this way, MDF and a pallet jack, once I got them out of the trailer with my overhead hoist. And Ive got some HEAVY stuff in there.
1/2" ply works good too, if your ground is firm, and gravel is pretty firm. You simply want to watch out for low places that a dolly wheel might break through. Shrug. Its not rocket science..though when you first start moving machines..it can be a bit scary.<G>
BTW..a pallet jack can be rented cheaply or purchased for less than $200. They will move most machines you are likely to bring home, and once you have started this madness called home machining, you will be needing it more often. With suitable wooden blocks, they also are nice for lifting the front of your vehicle for tire changes etc. <G> start laying in 4x4s...you will need them.
Gunner
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(Dave) wrote:

Still a huge improvement over a mill drill?

I'll have to rely on the retired machinists here for my moral support. I'm unlikely to get other help. Ok, so I put a dial gauge in or on the spindle and crank the table around to see how flat it is and how smooth the way edges are. Then I do this again while pushing and pulling on the table? Then I suppose I try to see how stiff the spindle is by pulling and pushing on it? Then perhaps I try measuring the backlash in the x,y, and z, and try checking the spindle runout? Seems like the best way to start would be to do this procedure on a machine in "acceptable" condition... or has this all been written down somewhere long, long, long ago?

Now that you mention it I've seen this done, indoors, when I watched an optical table being installed. I'm sure it would work for me too, although I might also need some landscaping and a come-along to pull the pallet jack up the hills. I guess I'm still unclear on how you get the machine up on a pallet though. Thanks for the helpful advice!

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On 9 Dec 2003 21:15:20 -0800, galt snipped-for-privacy@hotmail.com (Dave) wrote:

Hell yes!

Pretty much. Im sure others will tell you to put a mag base on it, then check the table for side slop etc etc. All you are trying to see is how much wear is there, and can it be tightened up with the gibs in a manner you can live with.

Pallet jack..no pallet.
Get a pry bar, and a chunk of 2x4. Lift up one end of the mill enough to get that 2x4 under it. Then do the rear. Then the front again, and replace the front 2x4 with a 4x4, then do the rear. Its now 3.5" off the floor. roll the pallet jack under it from the side and jack it up. remove the lumber, lower it down and move it. Simple. If you are worried about a machine sliding on the pallet jack, a couple small pieces of wood paneling or thing plywood between the pallet jack and the machine works wonders for keeping it in place, even at rather dramatic angles. Commonly used in moving stuff with forklifts that have well polished and slippery forks.
If pulling up hill,. find an anchor spot, and use a cable come along to pull it up the hill. Repeat as necessary until you have it where you want it. If the hill is steep enough to be a concern about tipping it off..hire out the work or troll the construction companies for someone with time on their hands and a Hydrocrane. A couple six packs of Pepsi etc and an ernest look go a very long way..along with a $20 bill or two. Its not rocket science..just scary at first. A hydro crane will extend its boom at least 30 feet with a 2500lb machine on the end of it.
Oh..NEVER get downhill of, or between anything heavy and a wall or someplace you can be trapped and squashed like a bug.
Just building up your confidence <G>
Gunner
Btw..this is a Hydrocrane..its often called a boom truck. You see them all over the place
http://kandlequipment.com/c-10T93.jpg
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galt snipped-for-privacy@hotmail.com (Dave) wrote:

I use a Johnson Bar.
Lower the table of the Bridgeport all the way down and crank it out to the operator's right side.
Pick up the right side of the machine with your Johnson Bar and have your wife stick a 4X4 under it on that side.
Pick up the left side and put a 4X4 on that side.
Pick up the right side again and stick (2) 2X6's between the 4X4 and the machine. Only put the ends under the machine, leave the 2X6's hanging out.
Go back and pick up the left side one more time and tap the free ends of the 2X6's in, under the machine with a sledge.
Walk round the machine with your sledge knocking everything into shape.
Use 3-1/2" screws through the 2X6's to attach them to the 4X4's
My wife and I picked up two Hardinge FSB lathes and a JET 4X40 engine lathe in less than 45 minutes doing this last Friday. They were all her tools so she had to do the heavy labor. I manned the Johnson bar from a safe distance.
If you are nervous about the machine tipping when you put a 4X4 under one side then step it up more slowly with a 2X4 though actually it can handle it in one shot.
Once the machine is up on its pallet, it can be moved very easily. Oh, and remember that the forks of a standard pallet jack are 27" wide, so your 2X6's need to be at least 35" long.
A drop deck trailer is a really neat invention. They come in many sizes. Rental Max has a 3,000 Lb trailer in which the deck is made of 3/8" (I think) plate and lowers all the way to the ground. This isn't a tilting trailer, the deck lowers flat to the ground. You can easily roll the machine onto the deck, crank it back up and drive away. 5 minutes tops.
George.
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(Dave) wrote:

Ok, you guys are helping me see that this is do-able. I appreciate it. I'll have to check around at the local rental places and see if any of them have such a trailer. Thanks!
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