Re: [CAD_CAM_EDM_DRO] My first cnc project!

adrian.astley@... wrote:

>Hello to everyone in the group,
>
>I am trying to help a friend of mine here in Costa Rica. I am a British Electrical engineer (plc's drives, controls etc more my bag)and he has a faulty CNC miller that I said I would help him sort out. The thing is the DANA Summit controller is not working - no feeback position and wont jog etc. This is hooked up to a Shizuoka machine with tool changer (22 off) which seems to work ok air operated and a relay output intiates a tool change I guess? I have seen the motors work by forcing 60Vdc on them and they go in both directions quite smoothly. There is no point in trying to repair the unit as it is obsolete and has no info with it. Is there a peice of kit that can hook up to the existing motors?
>

There are a couple of ways to go. For a full servo retrofit, you can
use EMC for the program, and
either the Servo-to-Go card or my parallel port motion control (see
http://jelinux.pico-systems.com/PPMC.html
for more info) for the interface. You'll have to decide whether the
servo amps are salvageable or
not. If not, then you need to find analog-input velocity servo amps,
perhaps on eBay. Or, you
can buy them from Copley Controls for a price that isn't too outrageous.

In between the full servo and plain stepper option is the pseudo-servo
arrangement. The computer
thinks it is a stepper system, with no position feedback, and outputs
step and direction signals to
either Gecko Servo or Rutex drives. These drives read the encoder
signals and move DC brush motors
appropriately. The disadvantage is you have no feedback to the
computer, and can't make advanced
decisions on following error proportional to velocity, and lose position
on a fault or emergency stop.

Jon