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Why the hate of bridgeport mills?

plastikdreams

Diamond
Joined
May 31, 2011
Location
upstate nj
I don't understand why so many look down upon bridgeport mills. I hear of them being inaccurate and not sturdy enough but I just don't see it. A lot of the work I have done is on bridgeports and I have no issues with them being accurate or stout enough when used within reason. My current mill will put a 3" 6 insert shell mill through a piece of 2024 .150 deep at 15ipm and 3600rpm with no issues, steel is a bit slower and not as deep, but again...within reason. As far as accuracy we hit +/-.0005 or better all day long, x, y, and z. These aren't new machines, and the dro's could probably use some calibration but with measurement before going to the number to hit you can easily get it dead nuts. As measured with mit digital mics that read .00005 and starrett digital height gages with bs half thou indicators and readouts to .0005.

It's not a hard concept, if I can do it why can't you?

Ps, I used to run 17-4 in a 2 axis bridgeport cnc'd mill every day with the same results.

Sure tolerances are there for a reason, but why not make it perfect if it only takes a few more minutes.
 
You won't hear me bag on Bridgeports. They were the "bomb" for almost 100 years. I think it's just that modern CNC designs have left the old mill behind. It will always have a place in the low-volume world, though, as it is still the most adaptable design for manual and light CNC work.
 
Stay within their capabilities and they are a fine machine.

If I had time and space I would love a short table short knee [9x32] step pulley J head. They are the original intent and they are a sweet machine to run.

We all tend to get 12x48 with 500 pounds of table to move and a varispeed howling in your ear, having to take a step to turn the handle.

It is not the same
 
No dislike of BPs here; I'd love one for the garage shop. They do great in the instrument shop at work. Still, people ask too much of them. Even with the best DRO they're not a 0.0005" machine. They go out of tram easily. The spindle isn't as rigid as a modern CNC, nor as rigid as a "heavy" mill. Used within their capabilities by somebody that knows what they're doing, they're great. What do I hate? Those stupid twist grip "safety" handles.
 
Stay within their capabilities and they are a fine machine.

If I had time and space I would love a short table short knee [9x32] step pulley J head. They are the original intent and they are a sweet machine to run.

We all tend to get 12x48 with 500 pounds of table to move and a varispeed howling in your ear, having to take a step to turn the handle.

It is not the same



I accidentally got a 9x32 J machine.. it was the best of the set at the machinery dealer- and you're right about them being an easy machine to run. Everything within easy reach, no walking around a long table; fits in a basement as easily as a garage. I put a vfd on, so haven't had to change the belts except maybe once or twice.
 
Can't say I've ever heard the hate for B-ports.... likely coming from the crowd wanting to do cnc quality work while cranking handles to DRO numbers...
 
No dislike of BPs here; I'd love one for the garage shop. They do great in the instrument shop at work. Still, people ask too much of them. Even with the best DRO they're not a 0.0005" machine. They go out of tram easily. The spindle isn't as rigid as a modern CNC, nor as rigid as a "heavy" mill. Used within their capabilities by somebody that knows what they're doing, they're great. What do I hate? Those stupid twist grip "safety" handles.

It's interesting I've had bridgeports that no matter how much you tightened the bolts if you tried to take a big cut it would shift the head, I've also had some that were just rock solid...weird lol
 
It might have something to do with the condition of the mill. The first 10 or so I used were completely worn out. a supplier/customer let me borrow his brand new mill for a few jobs. What a difference! Maybe that that is an indicator of something, you keep on using a machine that should be discarded or rebuilt.
 
Came across Cincinnati’s Treatise on Milling manual a few months ago. Last edition was in 1953. Those old guys were very sharp considering the Cinnci’s capability. Problem for me is space. Horizontals take up a lot of it! Cat 50 taper tooling, gang tooling, enough rigidity to mill to hearts desire-what’s not to love? For just milling I see where the horizontal is king. Adding the vertical head to the horizontal is a nice feature. That vert head is very rigid compared to a knee mill head. Plus you still have multi axis pivoting with some of those Cinci heads.

I have a Series 1 2J head Bridgeport at home. Good mill but rigid it is not. I sucked a small aluminum part out of vise a few a days ago(not enough clamp area). Head knocked out 0.010” one direction 0.012” the other. I like the Bridgeport however, I see where the horizontal is far more capable and rigid. Except drilling and tapping. The Bridgeport works well for most of what I do but if I can find and fit a horizontal I will bring one home.

I do like the Hardinge UM/TMs I have seen although they have a small work envelope and are limited to 5c collets. Delta and Clausing both have horizontals in the smallish size. Although the Clausing is hard to find.


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I'll bite. Every bridgeport I've ever used suffered knee rock, even brand new ones from Hardinge. The tram depends on how you approach the knee height and where the table weight is. Milling something in X that needs good flatness and straightness is a pain. I hate that. But it's also not unique to bridgeports, I generally dislike knee mills. I switched to an "L" type Deckel and was amazed it held 1 tenth flatness and parallelism on some 8" dovetails. I'm sure that involved some luck but I've never been nearly so lucky on a bridgeport.

There's nothing to like about R8 except its cost and ubiquity.

Bridgeports have really nice quills and spindles that are very responsive for drilling and tapping. Being a Deckel owner now, I miss bridgeport heads (the graduated quill with DRO, reversible spindle, and power quill feed). I believe the Deckel answer is the "fine boring head" but they still don't reverse).

Miss me with the "bridgeports are flimsy" BS. If your business is removing lots of metal in a rush, you already know a small manual knee mill is not the right tool. Otherwise Brdgeports are plenty capable. It's a well balanced design between being "stiff enough" and extremely versatile. They have the capability to take on parts that are larger than a 2400 lb machine should have any right to touch. My 10000 lb VMC a smaller work envelope than a bridgeport.

I would also like a 32" table bridgeport for a second mill, but I also don't care for round ram machines. Has anyone ever shortened a bridgeport table? You'd lose one of the coolant return troughs and would need a new endplate+leadscrew but otherwise it appears the casting would accept this.

I don't prefer bridgeports because they're not the right tools for much of my work (tightish tolerances on milled part geometry, occasional heavy material removal). I assume most other people hating on them are also thinking of jobs they weren't meant for. However they're excellent for intermediate tolerance general milling, drilling and tapping jobs and second ops on large awkward parts. Could it be that one machine is not the best fit for every job?
 
It's interesting I've had bridgeports that no matter how much you tightened the bolts if you tried to take a big cut it would shift the head, I've also had some that were just rock solid...weird lol

Notice where I said stay within its abilities

That it can take a 3/4 end mill does not mean can take a big womping cut with one in steel
 
Notice where I said stay within its abilities

That it can take a 3/4 end mill does not mean can take a big womping cut with one in steel

That's just crazy talk, there's a 3/4" collet for a reason :)

I mostly mean with shell mills, I prefer .375 and .500 endmills on my machine. I can take a reasonable cut without overstepping it's boundaries.
 
I never see them mentioned in threads, The series 2 special is the best one, but expensive used.
The extra weight of the base, box ways air assist knee makes a noticeable and nicer machine to operate difference.
 
Yes, there is a lot of criticism for BPs, but they are the most copied mill design in history. There are many reasons for that. Of course they are light, but then again so is most of my mill work. Because of their popularity, R8 tooling is made by everybody and inexpensive at that. What is not to like?
 
Some really old guys called it the machine that does everything, but nothing really well.

I bought a brand new standard step pulley 9X42 "Textron" machine in 1981, with, well, the only one I could afford "MiniWizzard" DRO, a"used"Kurt Vise, 10" Yowsah rotary table-$11000.

The Textron era, tend to have a bad reputation, but mine was pretty good, the ram was in good tram.
I used the machine first in hydraulics, then for Harley Davidson crankcase, and cylinder head repair, its a great machine for that! I was trained at the factory race department on one + rotary table.
 
Yes, there is a lot of criticism for BPs, but they are the most copied mill design in history. There are many reasons for that. Of course they are light, but then again so is most of my mill work. Because of their popularity, R8 tooling is made by everybody and inexpensive at that. What is not to like?

Top of the list? Not "hate". Simpler than that. Economic time-as-well-as-money "sanity check".

Probably a safe bet that no other vertical ever built has been abused as long, often, and badly as nearly any used BP you are likely to be able to buy affordably.

Folks who had them "ran what they had". Pushing cutters too large, feeds too agressive in impatience or desperation at trying to get more out of them in less time with less common sense if not also less skill. Goods were parked on overly-thin for their length tables. Sag they assuredly did.

That "over optimism" if not outright abuse, is not the fault of the machine.

It does seem to be an all-too-common reality written right into the worn-out bones of what is to be found as the survivors of it.

Buy a BP because you can get parts, rebuild advice aplenty from MANY others who have done it, and complete "turn-key" professional rebuild services, "store bought".

Which is a very good thing.

You will NEED some of all of those, often rather badly. UNdamaged BP's are just not common!

A "less popular" vertical - or even a "combo" - often has but a fraction the wear or abuse, might have NO significant table sag, need no rebuild - yet sell for less, even so.

The majority of the BP alternatives were ALSO more heavily built at the outset.

If buying brand-new? Most present-day alternatives remain better machines, just as they always were.

Get a 40-taper nostril, or even 30, 35, or B&S # 9 instead of the wimpy "are-ate"? You won't REALLY look back even once!

"What is not to like" about that?

:D
 








 
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