Adapting DRO for CNC use

[CaptnVideo]

I would like to use the existing Mitutoyo linear scales as the encoders for my cnc retrofit project. I see Mitutoyo sells scales for this purpose but why buy if I can use what I already have installed. If interfacing is needed, I wonder if the readout can be used for that purpose, possibly using the recorder outputs.

[scottsss]

An inter face would be needed, but it is were the inface would go to. Would it be software controled Such as mach 1/2 or would it be hardware controled.

I worked with Fuji IP-III. They had linear scales for X and Y. The interface between the scales and the servo's was at the controler and not software based. But I am unsure if Gecko or any of the other makes of controlers can currently do that. If they cn I would be interested since it would give and absalute position no matter the lead screw position and I could go with cheaper screws for the machine.

[CaptnVideo]

Thanks for the input scott. I posted the same question in the "Gecko" section and got a favorible reply. Looks like its do'able and has been done. I found a pdf file on the Mitutoyo website on their scales and am checking it out further.

[H500]

The servo controller might work if your dro output is quadrature and you have almost no backlash in your system. Otherwise the motor will vibrate back and forth by whatever amount of backlash you have.

[CaptnVideo]

I have already purchased Gecko 340 servo amps which do take quadrature inputs but the internal 5volt power supply is limited to 50ma and it looks like the scales require 300ma so an external power supply will be needed. I'll have to play with it and see what happens. Thanks for your input, I'm learning a lot here.

[scottsss]

So them motors would sort of gitter back and forth as they tried to find X.XXX1 say and they missed it by 2 or so. I had not considered that.

So with the DRO and Gecko's you would still need zero or close to zero back lash. Hmmm I'll have to check out the Gecko group.

I retrofitted a Taig with steppers and after a while wished I had gone servo with a linear scale like I've worked with before. But didn't have time to research if it was possible on such a small machine.

Let me know how the project goes. Later I might consider upgrading the Taig if your retro fit yields positive results.

[CaptnVideo]

I just got a note back from Gecko, they said the same thing an H500 in #4 above. So not a good idea. so now we have to find a good rotery encoder for our projects. Anyone have a suggestion or recommendation?