View Full Version : Bridgeport Boss Mach 3 Conversion Mill

07-14-2014, 01:03 AM
BP Boss 4 reconditioned and converted to Mach 3 located in central CA (Monterrey/Salinas)

Base machine is a factory modified Series 1 mill retaining all the features of the classic BP v-ram mill but modified for CNC operation with ball screws on all 3 axis and belt drive Nema 42 steppers. The mill also has a quick change spindle. The table is different (shorter & wider) and the overall construction is somewhat heavier as I understand it as well. Travel is 18x12x5" with the standard manual knee adjustment as well. Table size is 34x12-1/2" (working area, overall 46x16-1/8") The ways are chromed and the machine has a power lubrication system. Factory rated accuracy is 0.001", but with mircostepping theoretical accuracy now is 0.0001" though I would expect 0.0005" to be more realistic in practice.

The original 1980's electronics have been removed and replaced with Kelling 9082 stepper drivers (higher voltage & current rating then Geckos) using a modified stock power supply and a PC running windows 7 & mach 3. I have also installed a vdf drive for the main motor so the unit will run off 1 phase 220 and Mach 3 has full speed and direction control of the spindle.

The machine had been stored outside for a bit when I got it, so it was disassembled to a degree, stripped, inspected, cleaned and painted. None of the ways or critical surfaces had any significant rust and all are in good condition. The variable speed drive was fully disassembled for inspection and the keys and bushings were in good shape. All 3 stepper drive belts were replaced as well.

I am selling the machine without any tooling as the tooling I have is being kept for another machine. The spindle is a QC-30, but from what I understand many NTMB-30 tool holders will fit, and these are easy and cheap to find on ebay. I have 2 Kennemet NTMB collet holders that fit fine. My understanding is much of the American made tooling will fit, it's mainly the import stuff the doesn't, and that which doesn't can be modified to fit if you have a lathe.

Asking $4950 obo. This machine is in very good condition and is ready to go. Very capable good sized heavy duty machine, coupled with the easy of use and support of the Mach 3 system.

I have a trailer and can deliver the machine within a reasonable distance, but I do not have the means to unload it at the other end - you would need to have a forklift, tractor, etc at your end.