pic: Team 930 2004… thing

heres a strange perspective to a mechanism on our bot, shouldnt be too hard to figure out i think.

its an extendable, nonpivoting mast.

yeah, not hard to figure, but wow!
but is that rope?

its spectra

spectra is awesome. I love that stuff.

it definitely can hold its weight, and then some

Can somebody please explain to me how these types of lifts work. How do you get somethign to go up by pulling down? I understand how the multistage cascading lifts work. Is is the same thing?

It is really quite simple, it works the same way as a series of pulleys except for the fact that we use hdpe bushings with slots for the spectra to run through instead of a pulley. So as we pull down on the line in the innermost tube it pulls the end of the middle tube up until it comes to a hardstop. Then the spectra runs to the top of the middle tube, through a bushing which sends it back down to the bottom of the outermost tube, which allows the outermost tube to be lifted also. This can all be achieved with one piece of spectra, and they can be pulled down also with the same line.


what is spectra?

[/runs away]

spectra is the type of rope we are using. Its often used in sailing. I believe 1/8" spectra has a breaking strength of 1200 lbs., at least the stuff we have does.

Spectra cable is great stuff. In 2000 we used it to left our robot off the ground. At first we tried using just steal cable and it snapped all the time. We found out about spectra and it worked like a charm, we were hanging our 130lb robot from a hook that was connected to this cable. We also had a foreign exchange student from France that year and she was also a sail boat racer. She was GREAT with this stuff and could tie some amazing nots that really helped us. As long as you keep an eye on fringing or snags this stuff should hold up great.

A.K.A. to the camping world as “parachute cord”??

Or am I thinking of something else?

Parachute cord is usually spectra wrapped in a nylon sheath to protect against abrasion.

Ah, gotcha… I used that a lot in Boy Scouts since it was easier to deal with than braided rope for most things. - And it didn’t shed it’s material like rope does! lol