Digital readout from magnetic or glass scales

I searched and searched.....but nothing answered this question.

What about using Lunix CNC to build a DRO. Magnetic or glass scale, I think I will have to build the interface boards as I can not find a board that really takes care of it. I hate to just buy a DRO when I think down the line the mill will get a CNC conversion, But I really do not see ever CNC converting my lathe.

Thanks Guys!

If the scales output quadrature, you should be able to read them with
almost any linuxcnc supported hardware including a simple parallel port

PCW wrote:

If the scales output quadrature, you should be able to read them with
almost any linuxcnc supported hardware including a simple parallel port

So it looks like a Mesa 5I21 card will do the trick, I just need to find some scales and build a board to plug the scales into. I think I may end up buying a couple cheap scales to start getting things rolling, as I pretty much dont know what I am doing and starting from the beginning. I do have limited electronics experience. (I am an industrial electrician) I keep thinking about just using an Arduino but this has so much more power to go with it.


ok change of ideas. Since from reading the WIKI the 5i20 is about the standard LinuxCNC card. I think I will get one of those and a 7i47 motion oriented RS422 daughter card to go with it. Then I think the hardware deal should be good to go with 4 scales. Then for writing the programming and I should be good to go. Since both my machines are side by side I think I may setup so I just have all the scales going to one card and just switch back and forth in the software from machine to machine. .......

Thanks !!

Jake

LinuxCNC is pretty large overkill for just reading scales

if you do want to use Mesa hardware instead of a parallel port
I would suggest a 5I25/7I85S combination since its a lot cheaper

I am going to have a 4 axis setup on the mill, and a 2 axis on my lathe. I had originally thought of using Linux CNC since I want to CNC my knee mill in the future. Although the prices I have seen lately on older CNC mills it may not be worth starting at square one with a mill that was a manual mill to begin with. Retro a older CNC would be a better route.

I'm not dead set on using mesa hardware I started down that route as there is an abundance of information and support of there hardware. I may build a CNC plasma down the road also. So my thoughts of utilizing components that would help familiarize myself with the system was part of my other thoughts.

For the DRO I'm kinda thinking an Arduino base may be a simpler more cost effective route.

Newbies are a pain in the butt aren't they????

The Shuma Tech looks like the hot ticket for a somewhat DIY DRO. What are you using for scales? A ton cheaper than a 3 axis Mitutoyo with the inductive scales!


The Shumatech would end up being the same price as the Arduino route by the time I buy the Arduino Mega and the ttl to serial interfaces.



Back to the LinuxCNC route on controls I will have to look into the Mesa setup you referred to.

So if I did want to have a basic input to the computer with linux CNC I would need serial to parallel board then a parallel to pci board correct?

I have some steppers and servo motors around the shop somewhere....

Thanks again Guys!