View Full Version : Bridgeport Vertical Mill versions?

04-08-2006, 11:45 AM
I have seen several Bridge port vertical Mills that were called series 1, that looked very different from each other. Is there a description somewhere of the differences between series and versions within a series? What's the fixed head version? :confused:

Peter N
04-08-2006, 01:04 PM
Have a look here for comprehensive data:


Several different heads could be fitted including the standard J head, slotting head, cherrying attachment, as well as the copy mill which had the head mounted on a T-slot table with the copying attachment at one end.


John Stevenson
04-08-2006, 06:19 PM
The series one was the name given to the early CNC mills.
The manual mills go by the letters J, 2J and 4J.
The J is the step pulley version, the 2J is the variable speed version and the 4J is the larger manual machine based on the Series II CNC.

The Series I cannot be accurately defined as there were many variations.
I think Bridgeport had Friday afternoon machines as well ;)

Added to this some were built under licence.

There were some that had CNC on the table, X & Y but a manual quill, often powered by 2 axis Protrack controllers. Other tah the table these were the same as the manual machines with nod and tilt heads and long tables.

There were some produced with nod and tilt heads but Z axis motors fitted to the head that drove a clamp on the quill.
Not a rigid design and why do you need nod and tilt on a CNC?

There were also some produced with the short squarer table of the later CNC but again with the nod and tilt head.
The Z axis on these nod and tilt heads followed a few different designs, none all that good.

The last offering was the rigid ram version with as it's name implies a rigid ram, no tilt or nod.
These normally had the short square table but true to Fridays offerings some had the long manual type table.

The Z axis drive on the rigid ram was very good and consisted of the ball nut being built around the quill so there was no overhung brackets to bend , vibrate etc.

So to sum up a Series I can be one of many :D

04-08-2006, 07:15 PM
There was also the "M" series machine. This was similar to the "J" model but smaller, with adjustable drive belt, and a spindle that would only take up to about a 1/2" cutter. I believe it also had the tilt and nod head. It had a much higher low speed and only had a 1/2 hp motor. It was a most unsatisfying mill to use on anything more robust than aluminum extrusion.

Jim (KB4IVH)

04-08-2006, 08:56 PM
What version and vintage is this unit?
What is the pluses and minuses of this unit?


Peter N
04-09-2006, 02:09 AM
That picture is a Bridgeport Boss CNC mill. It's not standard either, the control panel appears to have been replaced with a PC.
I'm not sure about the age but I think it would be from the 70's, a forerunner to the Interact series CNC mills.

I haven't seen one like that for a long time but I'm sure there are others on here who will know a lot more about them.


04-09-2006, 04:16 AM
That's a Rigid-Ram CNC Series I mill. Much is like mine, but the control panel has been relplaced as said, and the knee is quite different from mine. I think this is earlier than mine and mine is from about 1979 or 80. Also there are some head controls that are missing on that one that are on mine. Still most of the head is the same, including the brake and the pneumatic speed control on the head. It probably also has the Kwik-Switch style tool holder spindle.

John Stevenson
04-09-2006, 04:24 AM
That's a Series I Boss machine,they also had a number after the BOSS tag.
1 to 6 had stepper motor drives indentifiable by the large finned casings over a standard type 42 motor.
The 7 to 10 series had servo motor drives and were sometimes called interacts, bit of a gey area.

This one in the pic I'm guessing at about a BOSS 5 or 6 because it has the Y axis motor mounted on the right and not underneath like earlier ones and it has an air powered brake [ cylinder on head at top left] plus air motor to adjust the vari-speed head, top right this time.

As Peter says it's been converted to a PC from it's original BOSS control which stood for Bridgeport Operating ? System.

If you are thinking of buying it [ looks like a sale machine, the manual is on the bed ] you need to know what controllers it's using and drivers.
Chances are the iron is good, many of these spent years parked up with electronic problems or in schools and colleges.

Tooling is special to them, get as much as you can. It's called QC30 and has no drawbar but relys on a special flanged nut on the spindle that grips the holder on it's special QC flange.

04-09-2006, 04:11 PM
John, are you sure that it's unique tooling? I ran a Boss 8 at one time, it had the locking collar just like you mentioned, but I'm pretty sure it used NMTB 30 tooling..


John Stevenson
04-09-2006, 06:31 PM
It looks like standard NMTB 30 and in fact the taper is identical.
Where it differs is the flange is smaller and thinner.

Standard NMTB flange is 50mm diameter by 8mm thick, 16mm cut outs.
The QC30 flange is 46mm diameter by 8.76 thick.

04-09-2006, 10:22 PM
Now that's interesting - I'll have to tell my old boss this.