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Originally Posted by WizardOfAz
Hi Al
You mentioned experience building vertical antennas - knew you must be an amateur radio op. I'm Bill Bennett, N7DZ, licensed since '68, originally WB8ALU in Cincinnati.
This is my third year with Team 1011 in Tucson. We're working on a telescoping arm design using a 2.5 x 1.25 tube inside a 3 x 1.75 tube. Plan to only have rollers at the bottom outside of the inner tube and the top inside of the outer tube. Have never done any kind of telescoping arm before, so we're out on thin ice here....
Also working on a design to PUSH the telescoping section, and a sliding apparatus inside it, up from the bottom using spring steel push tape, along the same idea as electrician's fish tape. No cables or chains. Hope we can get it to work...
Any comments or suggestions about this from Al or anybody would be welcomed.
Bill
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Welcome aboard, Bill, de WB9UVJ (usually /9 or /0)
Your roller idea should work but I have noticed that rollers bind with a little dirt in the path and stop rolling. Sliding delrin or nylon followers work but need some lube to keep them happy. It will be interesting to see how your tape idea works, the tetras are heavier than they look. We have used "spectra" cable (a nylon string stronger than steel, available from McMaster) and a couple of pulleys coupled to a two sided drum. The motor pulls down in one direction and pulls up in the other direction. A silicone super glide spray works for lube. Don't forget a couple of microswitches back to digital inputs on the RC to prevent over travel. (backed up by mechanical stops. back up the backup)
QTH 25mi. NW of Chicago-- licensed in '76, now an Extra--wthr hr cold abt 6 this am--cul--
73