Re: ATM Another fine 'string scope'

["Doug Tanaka" <dtanaka@seanet.com>]

> Doug,
>I have three tripod legs from a production
> prototype tripod that was never produced.....it proved too expensive
> to manufacture to be marketable.  The legs were hand machined and
> are very solid. Would they make suitable trusses for a string scope?
> can enough tension be applied by extending three part legs?

Hi Frank,

I'm pretty sure a good set of tripod legs would work very well.  I have
tried more than a few different schemes and extendable tubes was one of
them.  I used carbon fiber rods with locking levers scavenged from a cheap
tripod.  The problems I had were that the tubes were too thin and flexed a
bit, and I couldn't lock the levers tight enough, so they would creep with
heavy eyepieces.  Basically the problem was that the parts were all too
chintzy, and I didn't have a good tripod that I could spare for parts.  But,
I could tell that spreading by hand would put sufficient tension on the
strings as long as the secondary cage is relatively light.



> Oh, and I chuckle a little sometimes when I see the popularity of
> string scopes increase. About two years ago I posted to List for
> help from the guys with engineerig backgrounds. I wanted to make
> a scope with two trusses and balance the forces with wire.  They
> all proved to me that it couldn't be done and still keep the secondary
> ring stable. You live and learn. *S*
>
> Frank

I guess it's fortunate that I got into telescope making after you made that
post or else I would have known it wasn't going to work. *G*

Doug