Linear Encoders

I started a new thread since we really havent been talking about DRO's in this sub thread anyway.
I managed to delete the two messages i meant to reply to.

The first was the one that said the HP is a chip with a grid incorporated in its layout. If this is true, then do they have the layout we need for 500 lines per inch? i would guess that they are not willing to give up on the glass scale market. Anyone ever break apart an Accurite? The rotary encoders have a metal grid, i seen it.
if HP or someone else makes a detector that don't need a grid,that is great, and i think we know what to do. The other point is that if HP doesn't make the right chip that isn't stopping us from using the rotary encoder scheme.

Otherwise, I'd like to volunteer whoever it was that emailed UsDigital to ask them if they would print us some 500 line per inch and sell it without a head available, and we could use some of that in the head.

Finally, It seems that you could use the two head outa phase scheme to double the resolution of a grid as proposed in the other message i deleted. My thought is that the spacing would have to be correct, but that you could use ttl logic to convert the two signals into one.

Finally, i must say i am not totally committed to the "lime jello" approach to linear encoders, because my (currently imaginary) budget probably would include store bought encoders. However i am an engineer that can't say no to a project.
eric



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