A Simple Elevator

[Taylor]

When we did our 8020 lift in 2011, we found it to be a very simple, machine-less system. I can't speak on behalf of all 8020 distributors, but ours was happy to visit our site and work with us on our design and what parts we'd need to create it. We had to do minimal (read: a couple dozen holes drilled) machining on the system.
8020 also extended a FIRST team discount to us.
Our 2011 robot was far and away the simplest and most effective robot we've produced in our eight seasons.

[Brandon Holley]

Originally Posted by nnfuller

Do you have any examples of an adjustable system like you mentioned? I would be worried about things like adjustment screws loosening, but perhaps others have had success here?

Adjustment doesn't necessarily mean "turn a screw to adjust". It can be just a plan of attack on how to tweak things when you get down to your final configuration/implementation.

For our 2011 elevator, we used Teflon pads on the outside of the 1st inner stage of our lift (http://www.chiefdelphi.com/media/img...e4ed3dc_l.jpg). You can see the white little skids on either side up near the top of the elevator.

Knowing these were going to be our primary mechanism to eat up the tolerance stack up from the welding of all the assemblies and machining of the necessary brackets, we knew we were going to rivet these things on with countersunk rivets and shim stock behind them. The shim stock was the adjustment for the side to side slop. We only needed to tune it once on our final assembly and we were set for the year.


Just an example of how you can build adjustment into a design with part of your assembly. It doesn't need to be as elegant as bolt adjustments and the like, but of course pulling those off can be cool as well.

-Brando

[liam.larkin]

Want to 2nd, 3rd and 4th what many have already posted. We (272) have used 80/20 as the primary structural component on our lifts for years. 2004, 2007 and 2011. It has always served us well and we have little to no advanced machining capability. If you would like drawings (STEP files), pictures and/or videos illustrating our design please feel free to send me a private message and I will dig those up for you. GOOD LUCK!!!!

[JamesCH95]

Originally Posted by AdamHeard

Why steer clear?

Often times on our robots, due to our standardization on #10-32s and our love of lightweight manufacture, we can never even get close to proper preload on a bolt before we destroy the parts clamped. In these situations the spring force of a spring lock washer is helpful.

I agree for properly preloaded joints they aren't the solution, but it's surprisingly rare that we can properly preload on our robots without going to impractically small fasteners.

Link to older post.

Split lockwashers can cause bolts to work loose from vibrations sooner than normal. I'm coming from mostly automotive experience on this one, and have had miserable luck with split lock washers. I now avoid them on principal and haven't had an instance where I wish I used them (car, robot, or otherwise).

A belville or wave washer (or even an o-ring under the bolt head) might work for what it sounds like you're doing. But if you've never had an issue it's hard to argue with empirical evidence on FRC robots.

[BJC]

Wildstang had one of the simpliest to make elevators in 2011 and ended up World Champions. It was basically many C channels. You should contact someone on their team about some pictures or tips and tricks on that elevator.

[swwrobotics]

For the elevator, you could probably even use PVC pipes and just stack them inside each other, like a telescoping device on each side. Or you could get the special c-channel PVC, which I think you can get on mcmaster.com, and make something similar to Wildstang's design. This would probably be strong and save weight (since it's not metal) but our team has never actually made a forklifting device before so I'm not that aware if there would be any major problems of the design.