Brown & Sharpe beast retrofit

The latest machine in the shop to be retrofitted is a 1982 Brown&Sharpe V1000c. It is a 15000 lb beast with a 25 capacity tool changer, 2 speed geared headstock and will be fitted with an M&M precision rotab. Im using the stock resolvers with a 5i23/7i49 combination. B&S's were unique machines, built from welded boxes and using round linear ways. They have a short headstock and a long spindle snout like a boring mill. The machine originally had a GE1050 control that had ancient wiring that caused constant problems. Oddly enuff, the 1050 was one of the easiest contols I ever ran, simple and intuitive, just not terribly reliable, then again, no early cncs were.....The stock dc motors and Hi-ack amps will be retained. I do have a 15hp ac Fanuc spindle motor for it, but for now ,we will get it running with the original dc motor and drive. At the time of the picture, the spindle was being rebuilt, not a great picture. The second picture is the operator panel that was built for it, still being finished up.

Actually, I have a 7i33 for the encoder on the handwheel, spindle and the encoder on the rotab. Im using a 7i49 with a 7i83 for the operator panel and an additional 5i20 for the machine i/o with opto pb24 racks. The tool chain doesnt have an absolute position sensor, it is chain driven by a hydraulic motor and it has a large sprocket on the top of the tool chain(not to be confused with the drive chain) that a prox switch counts teeth on. Five teeth equal on tool pocket. The tools always get returned to the same spot on the tool chain. The control has to remember what tool chain postition is up, what tool is in the spindle and what tool is in the ready station waiting. The tool change mechanism its self is driven by a cam drum with hydraulic valves and limit switches. it was fast for its day. its a beast and a challenge and and a learning experinence and probably several other things. The only way I could think of to make some sort of absolute postion sensor on the tool chain is to use radio tags on the stations on the chain its self. The logic was pulled off in the original control, we will see if I can recreate history.

I think I meant 7i44, not 7i49. I cant keep track of all of it....early stages of senility, I guess. Anyway, I had the 5i20 and all the opto boards already, and the original machine wiring used them on outputs. I considered the sserial i/o route for this machine, and will use it for another project. Sserial is relatively new and Ive had good luck with it on operator control panels,.Im not ready to use it for machine i/o yet, Id like to try it out on something smaller, less complicated. I kinda think the 5i20 is getting a little long in the tooth anyway, the 5i23 does the same and more and is only 10% more expensive , for a simpler set machine, you cant beat a 5i25/7i77 for price, ease of set up. Id love to see a USB i/o breakout board, like a Pokeys, but not an HMI interface, to use for operator panels. Thats above my ability to build or program right now, but on my wish list.....upward and onward.

How is this project going for you?

It is going, not a fast as I would have liked. There were several things I did not anticipate, the first being it took 2 days to get the old control off and the miles of cable out, the second was having to replace the old servo amps, as they started to die while integrating the new control. I also had a genuinely weird homing problem on x&y initialy, weird hal thing......The amps were old and I have repaired them several times in the past. It was cheaper to replace them with AMCI amps, it just took a week to integrate them. Ive also been chasing never ending hiccups from old flakey switches and sensors in addition to just just plainly dumb stuff. Some on my end and some on B&S 's way, as they did some stupid things to save I/O.

Getting everything on the control panel programmed and working took about a week, the panel took a day to build. I added a tool in/out button on the machine itself. The original wonky B&S spindle encoder was replaced with standard encoder driven by a timing belt, which required a new spindle extension with .2 pich xl teeth cut in it, I also had to cut clearance in the head casting for the belt and build a bracket to hold the encoder, which took 2 days.I used the original GE relay panel and made some new ribbon cables, which go to breakout boards, this allowed me to keep the original hard wired estop/power on circuit. I had to add an additional relay for the z axis brake and another to pull the run relay to 0v , which pulls all the original power sequence down.

So as of now, the machine homes, spindle oreints with M119, free's with M118, shifts to low gear(5 to 1 reduction) with M141, shifts to hi gear with M142. The tool chain can be jogged cw by the + jog button and ccw by the - jog button, the transfer arm goes forward and backwards with the jog buttons and I can do a manual tool change with the Cam Jog Button actually using the tool changer. The spindle runs and has automatic hi-low selection by s code and m code, meaning , s100 m3 m141 geats you 100 rpm in low gear and s100m3m142 geta the same in hi.

Im working on the tool changer now, I have all the basic code written, there will be bugs and writing components is a litte tricky, things that seem like they shoud work dont. Its getting there. It is a big undertaking. The machine its self is simple, sequencing everything and keeping track of the tools is the difficult part. The z axis also requires some intense tuning on the amp, as the head weighs 3k pounds and isnt counterweighted, so it runs great z-, but strains up. The current loop on the new amp needs tuning. I also reversed the z polarity, as stupid B&S had it set up so z- was above the part!!

Thanks for the update. Have any pics of all this fun?

Would it possible to counterweight the head with chains and sprockets and a weight?