Re: [ATM] FW: wire spider

["Chris Dalla Piazza" <dalchri@hotmail.com>]

One of the reasons that I made mine was that I was forever bending my spider
vanes when trying to rotate the secondary for collimation.  Perhaps this
just means I should practice better technique.  I ended up with thick,
bright, multiple diffraction spikes in my images.

My wire spider was not offset like his.  It was a standard cross.  My
benefits were:

1) Diffraction spikes were now razor sharp and thin
2) Diffraction spikes were reduced in intensity
3) No longer multiple spikes

Of course, this was just aesthetic for my imaging.  I wonder if I would have
had any spikes or smeared rays show on my deep images had I used an offset
arrangement.

-----Original Message-----
From: atm-bounces@atmlist.net [mailto:atm-bounces@atmlist.net] On Behalf Of
Dominic-Luc Webb
Sent: Wednesday, October 24, 2007 4:00 AM
To: ATM Superheros
Subject: Re: [ATM] FW: wire spider


Looks like a lot of maintenance. Those of us who play stringed
musical instruments immediately recognize the material used. I
too have thought of ways to use strings, but did not like the
problem that strings degrade a lot over time. On the one hand,
there is what appears to be a tuner to adjust this. On the
other hand, I would guess it will need to be adjusted often.
On my electric guitar, I change strings every week. This makes
me wonder, with a grain of humor Mel....

How often do you change strings?
How do you tune this instrument?
Can one use, or will you develop an electronic tuner?
Which notes are best (E, A, etc)?
Should one use bronze, phosphor, platinum, or...?

More seriously now, while this is clearly very clever and
well built, I do not see much advantage to this. What led
you to build this?

I have also drawn from music, but not in same way. I like to
use speaker attenuator coils to get fine motions. That idea
came to me many years ago when I was working on microinjection
equipment to insert pipettes inside of living cells to
inject chemicals into them. Some of the ones with the finest
motion, like steps below 1 µm were made from speaker attenuator
coils. This can work great for precision alignment of optics.

Dominic

_______________________________________________
ATM mailing list http://www.atmlist.net/

_______________________________________________
ATM mailing list http://www.atmlist.net/