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DaveC426913
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I'd like some help from builders - modellers or mechanical tinkerers.
I'm trying to build the skeletons of some polyhedra - the vertices are intersections of rods - no faces. http://www.reed.edu/~mcphailb/puzzles/images/hex.bmp"
I want to be able to telescope the rods by about 3x. So, I could slide them anywhere between, say, 1" long and 3" inches long at will.
One way to do it is to use a rod-and-sleeve or piston design with brass rod and hollow brass tubing that you can buy at a hobby store. Trouble with this idea is that it won't compress to one third of its length - only half at best. To do a factor of three I'd need one rod surrounded by a sleeve surrounded by another sleeve. see attached diagram
It gets way more complicated when you add in mechanisms to stop the pistons from simply falling apart at full extension - they need slots and pegs, etc.
I'm looking for fresh ideas on how I can get the effect I want with less building and tinkering and with more reliability so that it doesn't fall apart. Less work would be nice too. If I can start with materials that I don't have to completely craft, that'd be great. I have to make 32 of em.
The rods should smoothly expand and contract by a factor of about three, yet remain rigid.
It doesn't have to be overly strong, I've been toying with plastic tubing and elastic bands and stuff.
Ideas?
I'm trying to build the skeletons of some polyhedra - the vertices are intersections of rods - no faces. http://www.reed.edu/~mcphailb/puzzles/images/hex.bmp"
I want to be able to telescope the rods by about 3x. So, I could slide them anywhere between, say, 1" long and 3" inches long at will.
One way to do it is to use a rod-and-sleeve or piston design with brass rod and hollow brass tubing that you can buy at a hobby store. Trouble with this idea is that it won't compress to one third of its length - only half at best. To do a factor of three I'd need one rod surrounded by a sleeve surrounded by another sleeve. see attached diagram
It gets way more complicated when you add in mechanisms to stop the pistons from simply falling apart at full extension - they need slots and pegs, etc.
I'm looking for fresh ideas on how I can get the effect I want with less building and tinkering and with more reliability so that it doesn't fall apart. Less work would be nice too. If I can start with materials that I don't have to completely craft, that'd be great. I have to make 32 of em.
The rods should smoothly expand and contract by a factor of about three, yet remain rigid.
It doesn't have to be overly strong, I've been toying with plastic tubing and elastic bands and stuff.
Ideas?
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