On Friday 13 April 2007, Ian Foster wrote:
G'day Roy, Vikki, et al.
Laser beams being coherent light will diffract around thin objects;
yes light bends. A thicker a long pinhole would be needed preferably
with non specular reflecting sides. As I Read Vikki's post this
morning I experimented with a laser pointer and a business card with
a pin hole in it. Having the laser a little way away from the card
allowed me to direct a thin beam on to the curtains about 400mm (16")
away. Laser pointers need a larger diameter beam so they can be seen
on a screen; contradictory to what we require for edge and centre
finding.
I was going to grab something thicker and try that based on
recommendations here. I'll probably still putz with it just for
jollies.
Thanks to Vikki's post I looked up the MicroMark link and purchased a
LC/EF on the spot; USD19.95; it will cost me AUD40 by the time it
gets to me in Oz. Thanks Vikki!
Thank you! I didn't even notice that, they dropped the price by $20!
Went back and ordered one myself at that price. We can compare
notes :).
I'm pretty sure I have spent at least that much on cheap laser pointers
so far :-).
Shipping isn't real bad, it is costing me almost $30 here :-).
Thanks for the wakeup :-).
Just for fun I took that junk wood dowel and made myself a nice little
file handle. Not perfect but the next one will be closer :-). I'm
also going to get some better wood next time I am at one of the home
improvement stores.
I tried out using the boring bar holder for the QCTP and it worked, not
ideal I don't think but it sure is simple and easy :). I forget who
showed me that here <blush> but Thanks!
In case anyone is interested, I put the pix up on the machine shop page
(top of projects). Please don't laugh too hard :).
Take care, Vikki.
--
Victoria Welch, WV9K/7
"Theres nothing to writing. All you do is sit at a typewriter and open a
vein." -- Red Smith
