Re: [ATM] Off-Topic: String Theory

[Jeff Lowe <lowe@nanotechsys.com>]

> Date: Sun, 9 Sep 2007 16:36:04 -0700
> From: "Richard Schwartz" <richard1941@gmail.com>
> Subject: [ATM] Off-Topic: String Theory
> To: atm@atmlist.net
> Message-ID:
> 	<3e5fde0d0709091636q1de1e1abtb6b4391d601a57d4@mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
> 
> My friend George has a problem.   He plans to build a hinged frame
> A-B-C-D with diagonals AC and BD. The sides will be one meter.
> Obviously the frame will be  "floppy" and will not hold its desired
> square shape.   To stabilize the frame, George plans to run a single
> string A-C-B-D, anchored at A and D, and with frictionless slides at B
> and C so that all of the wire is under the same tension.
> 
> George thinks this is a great idea because all you have to do to
> stiffen the whole frame is use a single tensioner like a guitar head.
> There is no need to mess with separate tensioners for separate
> strings.
> 
> George has grand vision of all kinds of giant self-erecting
> structures: airships, sailboat rigging, bridges,  domed sports
> stadiums, and even giant space colonies, and is about to contact his
> patent attorney.
> 
> But he is all bushed, trying to sort out the details, and has axed me
> to have you advise him.  As soon as he works out the details for the
> square frame, his first project using this principle will be a
> telescope truss.   He needs this because he expects to be unemployed
> in the near future.
> 

Have a look at Douglass Blanding's book:
_Exact Constraint: Machine Design using Kinematic Principles_

Lots of good thinking on how to build repeatable unambigious structures.


ISBN: 0791800857

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