Re: [CAD_CAM_EDM_DRO] bridgeport heidenhain replacement?

ebiz_59 wrote:

> I'm finally going to get a first hand look at a 1987 Bridgeport CNC made in England. It is said to have servos and a Heidenhain control with Z axis driver in need of repair. We have a little X2 with Xylotex controller and MACH3, and we are contemplating putting this Bridgeport together with a similar system, but I'm not sure how big a bite we are taking here.
>
> So, I need to look at the servo voltage and amperage ratings, but what else?? So I'm thinking that I might salvage the Heidenhain controls for someone else who might need them or a backup, and replace with a PC based control system and I'm looking for recommendations - both hardware/software as well as a time and cost estimate - please. Can I get this done for a few hundred dollars - say less than a grand, or is that a pipe dream?
>

If the servos and encoders work, and are already attached and wired, I
wouldn't replace them. The only thing you need is a new motor drive for
Z or a repair. You can run the machine with EMC2
<http://www.linuxcnc.org>, including encoders and real servo control
with feedback. You can pull a PC out of the trash and use that, or
spend very very little on one (a Pentium 3-800 is more than enough),
then buy a servo control system like the Mesa cards
(<http://www.mesanet.com>, look at the "Anything I/O FPGA cards" and
"Anything I/O daughter cards"). This will give you all the hardware
needed to do full servo control of the machine, plus enough digital I/O
for all the limit switches, home switches, spindle control, lube,
coolant, etc. that the machine should have. Total cost under $500,
roughly the same as buying geckodrives and a power supply. You should
be able to get a good servo amp for Z on eBay - they're usually in the
$100 range for the type of motor that's likely to be on that machine.

A simple parallel port system would barely give you enough I/O to run
the motors and connect a limit switch or two, whereas this will give you
48 I/Os in addition to 4 axes of servo analog output and encoder input.

- Steve