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View Full Version : Compact, constanwas t-torque telescoping mechanism

dentistbot
14-08-2016, 07:33
I'm old and crufty and only work on Battlebots now, but came across this super cool lift mechanism on reddit.

https://www.youtube.com/watch?v=oIuAAN0FbO8

It consists of a flat (in z) toothed spiral section locking together flat vertical helical sections with tabs, sort of in a locked version of that thing everyone used to do by rolling up a piece of paper and then pulling the inside loop one direction and the outside loop the other direction. The highlights of this design that make it better than say, a scissor lift are:


Constant torque throughout travel range
Final z height only proportional to starting x,y dimensions, so you can build this even in a super short bot
Made almost entirely out of low(ish)-precision sheet metal
Powered descent
Passive holding capability
Hollow, for passing game elements or wires through internally
Isotropically stable - it's rotationally symmetric about the z-axis


I'd love to see someone prototype this during the off-season.
Forhire
14-08-2016, 20:54
I'd love to see someone prototype this during the off-season.

Me too. That is a neat mechanism. This video shows the mechanism in greater detail along with an interview with the inventor.
https://www.youtube.com/watch?v=c-7b1b2R_Kg
JCharlton
15-08-2016, 16:08
Very cool.

In a similar vein is the Zippermast, perhaps a simpler way of achieving the same thing:

https://youtu.be/qWcncjSCLeE
JCharlton
20-08-2016, 01:38
And this:

http://www.serapid.com/en/industrial-equipment/industrial-lifts/industrial-lifting-products/rigibelt

Serapid have other designs too. Ingenious.

Who will be the first to do this on a robot?
nuclearnerd
20-08-2016, 10:39
And this:

http://www.serapid.com/en/industrial-equipment/industrial-lifts/industrial-lifting-products/rigibelt

Serapid have other designs too. Ingenious.

Who will be the first to do this on a robot?

I think it's already been done. I saw several teams in 2015 whose can burglars were made from IGUS cable chain (5407 and ?). I don't know how well they worked in general -the IGUS chain isn't meant to be structural :)
Knufire
21-08-2016, 20:29
I think it's already been done. I saw several teams in 2015 whose can burglars were made from IGUS cable chain (5407 and ?). I don't know how well they worked in general -the IGUS chain isn't meant to be structural :)

2451.
Lil' Lavery
22-08-2016, 04:35
I couldn't watch this with sound based on where I am, but can anyone relay what the basic benefits are when compared to a ball screw or lead screw?
Chak
22-08-2016, 05:23
I couldn't watch this with sound based on where I am, but can anyone relay what the basic benefits are when compared to a ball screw or lead screw?

The biggest benefit seems to be packaging. Ball screws and lead screws have to get longer and longer to lift things higher, and there would be a long screw poking above the platform being raised(annoying for purposes like theater). This new kind of lifting mechanism only have to get thicker and thicker around the base to lift things higher, and there is no rod poking above the platform. That makes for a compact unit that can expand upwards.

As for structural strength or power efficiency, I'm just a student watching some youtube videos so I wouldn't know about that.