DRO component list help

How to and what components would be required to build a DRO using a LCD 16-4 display or similar. The linear scale uses 40 um grating pitch, 5v lamp and 2 sin-wave transducer output signal. I'd like to use the output signal from the scale for positioning a servo motor driven linear axis.

I'd like to use the output signal from the scale for positioning a servo motor driven linear axis.

What does that have to do with a Digital Read Out?

OK, so you have a quadrature output, aka sine/cosine output. This is the same output from rotary encoders, so a good place to start is here:

http://playground.arduino.cc/Main/RotaryEncoders

PaulS:

I'd like to use the output signal from the scale for positioning a servo motor driven linear axis.

What does that have to do with a Digital Read Out?

Sounds like CNC.

Yes eventually I'll progress towards using the scale information to provide CNC control of the axis. If I should approach this as a CNC project from the start, any guidance will be appreciated.

Getting position sensing working first and then adding servo control later is a reasonable (perhaps even recommended) approach. Although, I imagine Arduino CNC has been done before, so you may want to leverage existing code (unless you just want the fun of the learning experience. :slight_smile: ).

I think most of the Arduino CNC stuff out there is based on stepper motors.

I'm very interested in seeing servo controlled CNC with an Arduino. It might require one of the ARM based Arduinos or variants like the Yun or Teensy 3.1.

For those who may only picture RC servos when we say servos - a servo-motor is basically any AC or DC (usually DC brushless, which is really an AC motor with semiconductor commutation) with position feedback. Most of the really big CNC machines use this rather than stepper motors.

polymorph:
I think most of the Arduino CNC stuff out there is based on stepper motors.

Oops, yes, thank you for the clarification. :slight_smile:

By the way, using a DRO-based CNC could allow you to use standard leadscrews (instead of expensive ballscrews) and cheap-as-dirt brushed DC motors (geared down of course) instead of expensive steppers/servos. Your setup will only be as accurate/trustworthy as your DRO, but you'd save a bundle of cash.

My axis drive has a 2.2kw BLDC motor with tach feedback. The motor is controlled by regenerative servo amplifier. Which Arduino control would be best suited for this application.

John252058:
My axis drive has a 2.2kw BLDC motor with tach feedback. The motor is controlled by regenerative servo amplifier. Which Arduino control would be best suited for this application.

Definitely the D73996F-0A, or maybe it should be the -0Y.

You need to give us some information to work with. How about a link to the datasheet for your motor controller?

...R

The driver is a Brown Boveri 05LE20 H-E regenerative servo amplifier.

John252058:
The driver is a Brown Boveri 05LE20 H-E regenerative servo amplifier.

I asked you to provide a link to the datsheet for the device. Or do you expect me to look for it?

...R

My apologies, I've not been able to get anything on the drive.

John252058:
My apologies, I've not been able to get anything on the drive.

Then I have no foundation from which to give you any advice.

...R