What are the pros and cons of using a telescoping tube kit for an elevator in a game like this one? Our example is that last year we had the AndyMark Climber in a Box for climb, and we were wondering if it is viable to use it as an elevator for game piece manipulation, along with any positives or drawbacks. Also, this would be specifically used for coral manipulation.
Thank you for any feedback!
Welcome!
The telescope tube kits can be incredibly versatile, but they do have limitations.
Could you share a longer description, sketch, or similar on what you would like to do? (E.g., reach level 3)?
One of the big downsides for telescoping tube kits when using them to score game pieces, is that because they use springs to move up, they are limited in the weight they can lift by the strength of the springs. This becomes a problem when you put a heavy game piece manipulator on an telescoping tube kit. However if you modify the kits so that you can power telescoping tubes both up and down they are much more useful.
Swyft has pretty good ones IMO
The idea would look something like this
I don’t think L4 would be involved in this sort of design. However, the idea is to have them on either side of the manipulator and mount it across them, treating them like elevator carriages.
So you will need a few things to make this viable.
Strong enough constant force springs to lift all of this up (including the game piece and all wiring/wire management).
Spools for the rope should be driven by a common shaft (or have very good positional control code)
The cross bar should be rigidly attached to the final stage on both sides
Be aware that:
The spools that wind the rope up are not guaranteed to wrap the same amount per rotation ( as the rope wraps on top of itself), this could in theory cause binding.
A COTS elevator is likely a more robust, reliable solution.
This is inaccurate. For instance, the greyt tube telescoping arm is extremely easy to modifiy to allow for actuation in both directions. We did so in 2023.
The telescoping tube kits only have bearing support one point on the inner tube. This means that side loads when the elevator is extended (i.e. from the weight a mechanism on the top, or that mechanism running into something) are transmitted directly into bearings via a massive lever arm. I’d also be worried about binding with side loads, especially as the season continues.
Compare that to an elevator, where side loads are taken up by many more bearings, separated by the distance of the overlap between stages (for a much less dramatic lever arm). In fact, it’s widely recommend to not let the bearings on a elevator come closer together than 6" for exactly this reason.
I would only use the telescoping arms for applications where there is mainly force in line with the direction of the arm.
It is, of course, entirely possible as a fair number of Charged Up robots demonstrated. Our robot that year could extend it’s arm sideways to the extension limit (48" that year) with a 15lb. roller claw mechanism on the end. We did have to use some very strong constant force springs to make it work, but it worked perfectly with no problems.
In general, @Skyehawk 's advice is excellent if you’re going to try and use two linked together like this. As he points out, it’s really stretching the use-case for a telescoping arm and a decent COTS elevator kit would probably do a better job of this. We’ve used two telescoping arms to climb in the past and can tell you that coordinating them as exactly as you’ll need to move one mechanism like you want to will be very difficult. We could afford a little dissimilarity in how climbing arms retracted because they weren’t actually connected to each other. But if you get the synch wrong on this, you could tear your mechanism apart (or destroy the arms if the mechanism turns out to be stronger.) That’s just not possible with an elevator. My advice is like most of the rest you’re getting…just get a COTS elevator.
