My shoptask is outfitted with a digital DRO that the manufacturer says:

encoder info:
 
 
 
pin number on encoder         wire color:
 
          5                                 yellow     Channel B
          4                                 green      +5 volt
          3                                 red          Channel A
          2                                 (none)
          1                                 black       ground
 
Channel A & B are TTL
 
each count is 0.0005 inch, or 2000 counts/inch
 
I don't know what a Mach123 is, but if it accept quadrature inputs, it may be ok.



So, does this mean I could wire these onto a few input pins as use it as an encoder?  I noticed he only has 2 channels, would I need three for all axis?

Richard

Richard:

  You need to hook up 2 channels for each axis. A & B are what Mach uses to read the encoder..

Art

So, for all axis I need a total of 6 outputs?  2 for each axis, correct?

Is this type of encoder a good solution opposed to encoders on the steppers?

Richard

IF you hook them up you will not be able to turn them to fast as the computer is only running a 25 - 45 KHz. Hope that helps

I have a shoptask on order that I eventually would like to cnc.  In the mean time I need a DRO.  I am trying to decide whether to get the DRO shoptask sells,
or build a shumatec kit with Chinese scales
or build a PC interface to some encoders from http://www.usdigital.com/products/and display the DRO on a PC screen.

I had been thinking of using the G-rex when I get the money and spousal permission to cnc the machine.  Now I'm thinking of buying the G-rex early and using it and Mach 3 or 4 to display the DRO.  I would use the usdigital linear encoders output into the x, y and z motor inputs.  Later, when I cnc the shoptask I would switch these back to the motor encoders.

My questions are:
1.  Do people ever use separate DRO readouts after they CNC their machines or are they redundant?
2.  The Grex uses ethernet.  Will there be to much delay between manually turning an axis and the display updating in Mach?

I would just set it up for CNC and get working with it like that.. But that is up to you
IF you set up with a Grex you will not need any other hardware just the Grex and the encoders! This may be the best way for you to get it running as it will also run your machine in the end. There is a delay but that is going to be down to about 1/30 sec (in the next firmware rev).. IF that is a problem ( and it shouldn't be) you are working to fast