Hello all,

I have a Cincinnati Sabre 750 running an Acramatic 850 control. The hardware is in great shape, and if you know how to talk to the original control it does a good job machining, still has tight tolerances, etc.
However, I can't interface with it easily and still trying to figure out the DNC to drip feed due to lack of space. Also the computer is a time bomb, the slightest thing that goes out can and will cost an arm and a leg.
So, I'm looking to retrofit with something more modern. I was looking at the Centroid systems, but I've been reading lots of negative about Customer Service and bugs lately, someone had mentioned Mach 3 so I though I would stop by and see i anyone
has any experience with converting a large VMC to Mach 3 or if it is more a hobby style controller.

Thanks in advance,

- Matt

so I though I would stop by and see i anyone
has any experience with converting a large VMC to Mach 3 or if it is more a hobby style controller

Dont have a VMC but have done a Bridgeport series 1 CNC, a Beaver NC5 mill (Bigger than the Bridgeport) and a  Computurn 290 Lathe which is quite a big machine, (about 3000KG with 21 inch swing)

Mach is very adaptable and there is not much that you cant do with it.

Hood

My main questions will be interfacing with the servos, spindle and tool changer. Servos are Red Cap Fanuc, spindle is an AC drive Fanuc servo. Yes, this one is a heavy machine, about 9,000 pounds of iron.

As the servo drives will  likely  be analogue input you would need to use something like the DSPMC or KFlop to convert the Step/Dir signals to analogue.

My Lathe has a 6 position rear turret and a four position front toolpost (have another 6 pos turret that will replace the toolpost one day LOL ) I interface the turret/toolpost via a PLC over Modbus.
Hood

The approach I've seen used adapting Mach to a machine with a tool changer and complex spindle control is to use a separate PLC controller to control the tool changer and the spindle, and have Mach just send commands to the PLC.

These guys sell reasonably priced PLC's:

http://www.automationdirect.com/adc/Home/Home;jsessionid=5e30595775d256d52290722859345d5b7367

I'd also take a look at the Modbus based I/O expander available from Peter Homann, it may have enough capability to control the tool changer:

http://www.homanndesigns.com/Products.html

Good luck-

Paul T.

Hmm, well I've got a plc and a couple expansion boards for it from a previous project that I guess I could use. 255 inputs and outputs will all the expansions.
I've got to get much more familiar with everything before I start tearing into a working (for now) cnc machine. Any suggestions on where to read up on interfacing in general for a VMC?

Thanks all

Matt

Your PLC will need to have ModBUS.

Cant really point you to a specific place for interfacing as it will really depend what you have. If you can find out whether your drives are +-10v analogue  command only or if they are capable of Step/Dir that would be a start.

Hood

Ok, I'll do some checking on the model #'s and post back up.

Thanks for the help

- Matt

Greetings KEFAFU:

I am retrofitting one of my early 1980's 4-axis mills, using the Vital Systems DSPMC controller. They (Vital Systems) worked with Art developing the firmware to run with Mach3. The manual and related software AxisWorks (motor tuning, PID graphical interface) is very well written, and thorough. The controller interfaces with the PC through an Ethernet crossover cable.

The old proprietary controls are not worth spending the money to repair; (1) Parts are hard to find, (2) the circuit boards costly if you can even get them, (3) they are really ancient technology, (4) the controls are filled with zillions of wires that have become frayed, insulation in doubt, and generally a nightmare to figure out, (5) even if you could get the original schematics and prints. which more often you cannot, (6) the screen is an obsolete, bulky CRT, with a crappy visual look, (7) and a nice color touchscreen is out of the question! ( and the lack of memory was a joke, and the "drip-feed" involved special boards and connections.

The PC, and the evolution of electronic micro-circuitry has revolutionized the machine tool industry. The big, corporate proprietary controls are all gone bye bye, along with their super costly maintainence and ridiculously expensive parts. Good riddance!!

Mach3 is a constantly evolving control interface, with the very writers often on this forum answering questions, and helping to make the solutions. Mach v.4 is in the near future, and the network of professional users/experts/ worldwide is the icing on the cake.

Regards,
John

Hi Matt,

I am about to undertake the same conversion on a sabre 750 with 850sx controller.  I would really like to hear how it went and with which hardware you have decided to replace the outdated cincinnati equipment.

SK