Position feedback

While perusing the internet I came across this interesting chap:
Digital Caliper Pinouts - Robot Room

The modules he is using are pretty cheap, $8.95 from the US:
Digital Caliper With Data Output Port

I was planning on using either hall effect or inductive proximity sensors wired into an arduino for limit switches so I will have enough ports available to put 3 of these bad boys

Would it be possible to use 3 of these digital caliper modules to provide absolute position feedback on a CNC router at low cost I'm not sure if a cnc machine's rapid movement would prove to violent for calipers to measure accurately to their usual precision, any thoughts?

have a search. Both Robin and I have built DRO using digital calipers. the read rate is far too slow for use as an active feedback of position, realistically with settling time its half a second or more. fine for the manual mill though.

mind you, these would be worth buying to get the cable, as those are like hens teeth and cost more than that on their own!

I ordered one because I needed one anyway, did you use the nerdkit setup for the mill?

NerdKits - Digital Calipers DRO

No, I designed, built and programmed my own.

http://www.mycncuk.com/forums/genera...-idea-dro.html

That is a good thread thanks, have to file it away for future reference. :)