THEN

The earliest Bridgeports were the famous "round arm" machines. This describes the top overarm which was a long round casting which the head was mounted to. The latter models have a dovetail slide in their place. Hence the name "dovetail overarm machine". Most round arm machines had the M-head, 9" travel knee, and a 32" table. As the years passed a 36" table was introduced followed by a 42" and lastly a 48" table. The knee travel was increased to 12". The heads went from the 1/2hp M head to a 1hp J head to a 2hp 2J variable speed head. The Bridgeport of today would have a 2hp 2J head with a 48" table and 12" Y axis travel.

Along with the different sizes, "chrome ways" were introduced. The hard chrome plating of the ways is a very effective means of extending the life of the way surfaces.

The first Bridgeports were equipped with grease fittings as a means of lubricating the ways. The introduction of the one shot lube system greatly improved the lubricating of all of the critical wearing surfaces and parts. Today the use of an automatic lube pump, which is on a timed cycle, improves the lube system still further.

The early power feeds on a Bridgeport were large heavy gear boxes that had to be manually shifted for every feed rate. These power feeds were so heavy that over time were known to actually put a bend in the table. Another drawback was that they were only designed for the table (X axis). The power feeds of today are very light, infinitely variable units that are available for any axis x, y, or z. These units are also equipped with a rapid traverse button and some even have a rotation counter built in.

NOW

As we came into the 21st century with Bridgeport feeling the pressure of  imported copies, a licensing agreement was made with Hardinge Inc. In 2002 Hardinge Inc. moved the production of the famous Series I knee mill to its headquarters’ in Elmira, New York. Two years later Hardinge Inc. acquired the Bridgeport brand and took over the entire line of mills and CNC machining centers. On solid footing and now as part of the Hardinge Inc. family, Bridgeport will continue to grow with innovative and productive milling solutions.

Specifications of Today's Bridgeport

Table Travel (X-Axis)                                                                      36"
Saddle Travel (Y-Axis)                                                                    12"
Knee Travel (Z-Axis)                                                                      16"
Quill Travel                                                                                      5"
Ram Travel                                                                                     12"
Table Length & Width                                                                      48" X 9"
T-Slot Size                                                                                      0.625"
T-Slot Center Distance                                                                    3 @ 2.5"
Weight of Workpiece (Max.)                                                            750#
HP Rating 30 Minute Duty Cycle                                                    3 HP
HP Rating Continuous                                                                    2 HP
Collet Size                                                                                      R-8
Quill Diameter                                                                                 3.375"
Feed Screw Diameter                                                                    1.250"
Feed Screw Pitch                                                                           0.200"
Vari Speed Range High Gear                                                        500 - 4200 rpm
Vari Speed Range Low Gear                                                        60 - 500 rpm
Power Quill Feed (3) Range             .0015", .003", .006"  /rev.
Foor Space                                                                                   8.2' X 5.3'
Machine Height                                                                             6.8'
Machine Shipping Weight                                                              2095#