Bridgeport Boss 9 R2E4 convertion

I resonantly acquired a Bridgeport boss 9 R2E4 series 1 CNC mill made in 1985. The controller is died but still in very good mechanical shape. The machine has 3 DC servos, coolant and mist systems, automatic oilier and a bunch of other systems. I am starting the conversion to using LinuxCNC and thought others would like to see this. I am I know that this has been done before and how it is done has been documented, but though I could show what I am doing and maybe get some help in the process.



Goals (kind of in order):
1. Convert this machine to run LinuxCNC
2. Use as many components on the machine as reasonable
3. Do this on a small budget
4. Do this conversion as painlessly as reasonable
5. Convert the spindle drive to use a VFD
6. Possibly add rigid taping by adding spindle encoder

What I have and have done: I have the machine moved into my garage and connected to 3 phase power by means of a rotary phase converter, this is how I know the original controller is died. I have the control computer build less the hard drive (in the mail, 60GB SSD), also the mesa card(s). This is the first part that I could use help with, I was thinking of use a 5i23, 7i33, and 7i37 or maybe 6i25 and 7i77, thoughts?

go with the 5i25 and 7i77 addon and a second general i/o card , as the servo drivers are 10v analog input this will make it easy going for you

My concern was the limited number of IO of the 5i25 at only 34 vs the 5i23 with 72. This is not going to be a limiting factor?

no i agree , i was just looking from the other perspective of using the newer range of cards , with the smart serial for extra inputs , such as the 7I73
with the 7I77 you will at least have a VFD 10V analog output for spindle with fwd/rev outputs already .

either way at least your spoilt for choice

I was not aware they had any thing like the serial connection in the LinuxCNC support, I thought there would be a bit of a buffering problem there. Very good to know. What about the 6i25 then?

yes the 6i25 is supported , it shows as a 5i25 and is identical

I guess I am not sure about a serial link to the 7i77 and other sub boards that handle functions like encoder, servo voltage, end stops, E-stops, and so on. I thought there was a latency consideration with using this kind of link. I am not opposed to the idea, I kind of like it, I just dont want to find there is some limitations that I was unaware of.

If I understand this correctly I have 6 servos, 16 outputs, 32 inputs, and 1 RS-422 output that I can connect to any serial daughter board and that's not even using the second connector on the 6i25? That's pretty COOL! So can I use second connector on the 6i25 for a 7i74 and go to 8 more serial daughter boards? Even better!

If this would work I am doing this over the 5i23 and the greater number of IO.

Well it would seem that PWM and encoder counting are done using a FPGA, CPLD, or Micro controller (i am not sure whats on the board on the 7i77). But that handles the short term buffering of encoder counts and generation of PWM signals.

Awesome 6i25 and 7i77 it is!

I have this exact machine except the control is working perfectly. When it dies, I will convert to LinuxCNC.

I just converted it from 480 3 phase to single phase and added a vfd. The only issue is I have to make sure I disable the vfd before the R2E4 brake comes on and it shuts the spindle or else I get vfd error, and have to reset it.
There is a way to get around this but I have had no need at this point. I am working on a VMC retrofit.

Just my thoughts......

The 5i25 and 7i77 has plenty I/O to convert this machine. Don't now why you would need anything else.

Let me know if you need schematics. I have them all for the machine. Biggest issue is replacing the EAF board, which handles the I/O (PLC) portion.

Irewired the trannies for single phase 220 and it has been working like a champ. This thing is a tank.
The spindle makes a little noise, but that is a known issue, bushings need replacing.

I came close to cutting cables, but got the existing control working.