Bridgeport Series 1 and 2 differences

[TheShooter]

Is there a place that details the differences between a Series I and Series II Bridgeport?

I see several references to both Series models, but have not quite figured out the differences. Really - I am too lazy to look at the listings on all the places that has them for sale and figure it out.

You all being the SME's (Subject Matter Experts) someone surely has a simple list.

[Milacron of PM]

Series II is like a Series I on steriods. 2,200 lbs vs 5,000 lbs for starters. Series II has much lager head and with DC motor on quill feed. No. 40 spindle vs R8. Integral power feed on X axis on II. II has wider/longer table, more travels, square ways on Y.

The main disadvantage of II is the head is so large that tilting it becomes such a PITA that one is almost never inspired to actually do so. Hence, the Series II "Special" model with II body and I head. Actually more desirable and sought after than the Series II.

Of course just to confuse matters, sometime in the mid 1990's Bridgeport dropped the Series II and only offered the Series II Special....but then since if was no longer "Special" they dropped the "special" in the name and just called it a Series II !!! So, multiple dope slaps to the slackards at Bridgeport for that one, but hopefully this is clear as mud.

[The Doctor]

Think of it this way- A series II compares to a series I much as the series I compares to a mill-drill I'm not joking, after using the series II special at work my series I seems very toy-like.

Ed

[HTRN]

Like D Thomas said, the Series 1 machines are worth more money, with Series II's bringing in surprisingly little (usually in the neighborhood of 3 or 4 grand), and are often thoroughly beaten - one does not buy a $40K dollar manual mill(I'm not kidding, that's what they went for circa 1994) to do light work. Also contributing to the problem is the dirth of spare parts - while the Series 1 is basically an updated "J" machine, which means alot of the parts are interchangeable, the Series II is a whole nother animal. Interestingly enough, the Series II appears to be the basis of some of the Boss series CNC machines.

Series 1:


Series II:



HTRN

[SJorgensen]

Mine is a Series I Rigid Ram mill without any manual handles for the X, Y or Z axis. Sturdy is a good description but it is useless without a program or its controller.

[Milacron of PM]

Like D Thomas said, the Series 1 machines are worth more money,

No they aren't and that's not what I said. A pristine Series II generally brings more money than a pristine Series I, even today. But what is really sought after, is the Series II Special...which is a Series II body with Series I head. Except after the mid 1990's they dropped the "special" moniker, such that all of the later "big Bridgeports" are Series II body and Series I head.

[Wirecutter]

I'm glad the question was asked, then. I had thought that the difference between the Series I and Series II was the continuously variable spindle speed system. But that's just a couple of variations on the Series I, apparently.

I have a Series I with the step-pulley spindle, and I use a VFD to provide (three phase power and) fine variable speed. Once in a while, I move the belt on the step pulley, slightly more often I just switch between high and low range. The speed and direction control is handled by adjusting the VFD.

I think my setup is actually superior to the variable speed head, because the head is much simpler and easier to fix. The VFD is easy on the machine because it has a soft start for the motor rather than the "jerk" start of just flipping the drum switch.

Why isn't this better? (..than a variable speed head, not a Series II)

-Mark

[John Stevenson]

Mark,
It is better. If VFD's had been around Bridgies may have gone this route.
I have a varispeed head machine, not by choice , it was what came up but if I had to make a choice I'd go step speed with VFD.
The Varispeed heads are noisy and prone to wear on the sheathes but in their heyday there wasn't much of a choice.

.

[rockrat]

The Varispeed heads are noisy and prone to wear on the sheathes but in their heyday there wasn't much of a choice.

After changing the belt to change speeds on an older model BP (over and over what'a PITA), I would take the chance on the Varispeed as well. It was a fantastic upgrade at the time.

But I agree, a VFD solves so many issues.

Nice thread by the way. Thanks for starting it Shooter.

rock-

[torker]

After changing the belt to change speeds on an older model BP (over and over what'a PITA),

OK...on the Series 1's (8 spd J head) and the BP 8 spd clones...just how involved is a belt/speed change? Surely it can't be worse than my mill/drill where you have to climb up into the thing with wrenches to loosen and tighten bolts...all the while jerking on the swivel motor mount to tension the works.
Thanks!
Russ

[HTRN]

No they aren't and that's not what I said. A pristine Series II generally brings more money than a pristine Series I, even today. But what is really sought after, is the Series II Special...which is a Series II body with Series I head. Except after the mid 1990's they dropped the "special" moniker, such that all of the later "big Bridgeports" are Series II body and Series I head.

I've honestly never seen a "Special". And from what I've seen, the Series II's the last coupla years have consistantly garnered less money than the Series I. It might be different where you are, given the nature of the local machine shops(big work requires big machines).

As for the Pulley/Variable speed deal, I too think a pulley machine with a VFD is a better way, no sheeve problems, and the machines are generally cheaper. I'm surprised the clone mill makers haven't made this a standard option, and skipped the stack of pulleys for a coupla cogged belt pulleys(instead of 6 speeds it would have two) and a VFD..


HTRN

[Marc M]

OK...on the Series 1's (8 spd J head) and the BP 8 spd clones...just how involved is a belt/speed change? ...

Russ, it's no where near that big of a PITA - no wrenches needed. On either side of the motor is a short handle attached to a 'nut'. Loosen both, the motor pivots on one side to slack the belt, swap pulleys, push the motor back to tension and tighten the 2 handles. Due to the weight of the motor its really easy to hold tension on the belt while you tighten it. Less than a 1/4 turn is needed on the handle to lock it down. Been a while for me as I went the VFD route. Only complaint with the VFD is it makes my VRO do the hula if the motor is running on the high speed windings.

Marc-

[Milacron of PM]

I've honestly never seen a "Special". And from what I've seen, the Series II's the last coupla years have consistantly garnered less money than the Series I. It might be different where you are, given the nature of the local machine shops(big work requires big machines).

Not knowing "what you've seen" makes your experience base questionable. The fact that you've never seen a Series II Special, when there are thousands of them out there, gives me some hint that "what you've seen" isn't much.

"What I've seen" is over one hundred auctions in the past 6 years, and can say, that a Series II will *always* sell higher than a Series I Bridgeport if the two machines are in the same condition It's possible you are comparing worn out II's to pristine I's, but that would be an irrelevant comparison if so.

[rockrat]

OK...on the Series 1's (8 spd J head) and the BP 8 spd clones...just how involved is a belt/speed change? Surely it can't be worse than my mill/drill where you have to climb up into the thing with wrenches to loosen and tighten bolts...all the while jerking on the swivel motor mount to tension the works.
Thanks!
Russ

It aint terrible, and if it was all I had, I could get by nicely.

But having to do a little production job on one and changing the speeds to get from endmill to drill and back again is a pain. The belt change also was a bit higher up as I recall (might be off here, never measured) and it seemed that the shorter of our fellow machinist would complain a bit about changing speeds. The guy I'm thinking of had to have a step stool to change belts, but seemed to be able to turn the speed dial without much effort.

I'll take the varispeed today, especially when all I have to do now (on the non cnc stuff) is turn the little handle and / or flip the lever. Plus, if the surface finish on your flycutter aint quite right, just turn the speed handle and observe how the finish changes. Belts, you get close and accept it.

Again, if I had my preference, give me the varispeed over the belt change any day. IMHO

rock-

[John Stevenson]

I love Varispeeds, loads of dosh.
Just done another motor shaft jobbie this week on a varispeed where the keyway had worn badly, similar to the one I posted the other week.

Just because a machine was built with various features it doesn't mean you have to stick with these for life. If VFD's were available reliably years ago many more manufacturers would have gone this route.
Look at machining centres, massive motors with VFD so that you have the nessesary torque at low speeds which is what counts.