"Karl Townsend" wrote in message
anews.com...


Your laser digitizer sounds interesting. Please tell me more about it. I
do a lot of designs for my CNC plasma table by taking a photo of the part
and turning it into a .dxf file but accuracy suffers a little in the
process and I end up checking all the measurements if it is a critical
part. Artwork isn't too fussy but some of the machine and equipment parts
I do need to be right on.
Steve

I bought an Omron laser displacement sensor off eBay. It puts out 4 - 20
milliamps over distance of 1.1 to 2.0" away. I mounted it in a taper 40
holder. I then go back and forth over the part in my CNC mill and record
distances plus X,Y,Z dimensions off the control. You end up with a ton o'
points. Then the hard part, make it into something usable. So far, I'm
learning Rhino. I'm not too good at this step.

If you got time, there's also a point probe that you can build or buy.
With that you move the mill to an X,Y location and then move Z till the
probe touches; record point;repeat. Much slower and slightly less
accurate. But still way more than you'd need for a plasma cutter.

I did the photo to .dxf thing with my business sign. Next time you drive
by, look at the new signs. Took more time than if i had just started over
from scratch.


Karl

I'm scheming about making one using a Leitz laser "tape measure" device and
a homemade gantry -- big enough for a car. I've tried it with a similar
instrument made for Stanley by Leitz (FatMax TLM 100 -- around $100), and
the concept works. The Leitz-branded model has signal output; the Stanley
does not, so I'll use the Leitz (around $400) if I get serious about it.

I made a similar gantry around 25 years ago, using a plumb bob and tape
measure, and a wooden gantry aligned with a single stretched steel wire for
the longitudinal level along the car's wheelbase. It took forever to take
measurements at a 6" grid but it did work. The laser measurer could make the
whole thing very practical.

--
Ed Huntress