Re: [ATM] New minimalist single-pole 18" ultralight

[Richard <cnc@cncservo.co.uk>]

Hi Mike,

Monday, May 21, 2007, 5:49:00 PM, you wrote:

ML> My strategy for shorter poles (at least for my 8" travel scope) is to 
ML> use multi-segmented, shorter trusses.

ML> I also considered having truss poles with joints, and this type of 
ML> joint might be interesting, though costly, but that is not such a 
ML> concernt with one pole:
ML>    http://www.sandsmachine.com/spec_ssc.htm

ML> It is intended for bicycle frames and is made by the same place that 
ML> has the surplus aluminum disks that many of us find very useful.

One look at that joint, lovely that it is, and you don't need to look
at its name to see what it's designed for. To resist torque. Is that
really what you need in your application Mike, or is it tension and
compression that is your aim?.

There's a lot to be learned from the machine tool industry where huge
cutting forces are transmitted through toolholders whilst holding
tremendous accuracy, and the one common element you will almost always
see is the taper joint. Where diametric adjustment is required, the
collet prevails, usually in association with a taper. A tapered collet
would give you an optionally telescopic adjustable, breakable joint
which is both accurate and strong when tightened, and it can be done
with off the shelf components with fairly light weight.

Best regards,
  Richard in the UK

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