Re: [CAD_CAM_EDM_DRO] DRO ENCODER TOOL

>
> From: Par Willen <pwillen@...>
>
> Mike Gann wrote:
>
> > I knew about US Digital. I was hoping this was something
> > else, as I was looking for a little higher resolution
> > linear encoders. (cheap)
>
> "Me too."
>
> Anybody here know of any higher resolution (> 360 lpi) strips that will
> work with the HEDS-9xxx encoders?
>

I typed a long and detailed reply, then fat fingered the send, and lost it.

Remember, the resolution of the 360 lines/inch ends up being 4 X or 1440
counts per inch.


Here is a short version, if anyone in interested, I'll elaborate.

All you get for you money from US Digital is a strip of plastic with lines
printed on it.

All you get from HP for 30 bucks is $2.00 worth of LEDs and Photo Transistors
in a plastic block.

This is all these things are, and I would think people here could easily make
them out of a handy chunk of metal and make them in a resolution appropriate
to the use we have in mind, rather than what an ink jet printer wants.

Excuse the ugly ascii art.

X = Metal or Plastic

XXXXXX| L |XXXXX| L |XXXXXX
XXXXXX| E |XXXXX| E |XXXXXX
XXXXXX| D |XXXXX| D |XXXXXX
XXXXXXXX XXXXXXXXX XXXXXXXX
--- --- --- --- --- Plastic Strip (- = Black Spot)
XXXXXXXX XXXXXXXXX XXXXXXXX
XXXXXX| T |XXXXX| T |XXXXXX
XXXXXX| R |XXXXX| R |XXXXXX
XXXXXX| N |XXXXX| N |XXXXXX

The Light from the LEDs shines thru the hole and then is either blocked or passes
thru the plastic depending on the position of the lines.

The spacing between the sensord needs to be such that sensor sees the edge of one
line at the point the other sensor is dead center on another.

Pretty basic. the real job is going to be mounting them, and that will need to be
done either way.

Marc