Extendable Arm (Telescopic Arm)

Ok so when I was in FRC during the 2011 season i always saw teams with telescoping arms with grabbers on the bottom. Now my team that year had an elevator lift and honestly that was fairly complicated to implement into Vex (I mean yeah we have a prototype) but we wanna do more. We came up with the idea of FRC 233 or FRC 2949 style telescoping arm but the problem is implementing that with vex components. Also still dont really understand how those work to the fullest extent. Any help will be greatly appreciated.

There are a few different ways to build an effective and efficient elevator lift in Skyrise this year (I know from experience). There is a thread currently dedicated to discussing elevator lifts for this next year.

If you want to see an example of one, this is a video of my teams robot in Sack Attack using our elevator lift.

Youre #7702 i Loved your lift design we are trying to mimic it but we want it to be alot lighter and use the 1x2x1x35 or 25 C- channels but cant get it all lined up

This won’t be lighter. You’ll need 2 C-channels (which is a weight ratio of 8:7 by counting holes), plus a bunch of standoffs that the 5-wide version doesn’t have. It feels much more open, but I don’t think it’ll be lighter after some vague number crunching.

Skaters idea will be lighter, but I don’t know if it’s as structurally stable as either of the c-channel options.

In my experience, there wasn’t anything wrong with using the 5-wide channel, and doing weight trimming will probably get you negligible performance gains when comparing the three designs. You’ll get gains when you compare steel and aluminum and when you reduce friction, but weight is not going to be your biggest concern.

I was on 2949 during the 2011 season (Logomotion) and was lead student design for it. I can definitely answer any questions you have about it, or how it could transfer to vex.

That being said, I’ll be the first to say from our team that an elevator was by far much better for that season then the rotating telescoping arm.

Like I said, I’ll answer any questions you have.

FYI: 2949 is now 2451. Changed numbers for the 2013 season, but still PWNAGE.


I was at Midwest that year Team 71, yeah we love the idea of an elevator but we also like the idea of just specializing in the skyrise section using a rotating telescoping arm with a wrist on it. But yeah Ive been interested in like how it all works like people are saying to just line a piece of metal with the racks and put a motor with a pinion at the end of it so that it is able to telescope. But i would love to have your input.