Rubber bands are great and all, but are there alternatives that we can use that are also legal? The main problem I have with rubber bands is they lose their elasticity over time, meaning mechanisms built around rubber bands become less reliable. Maybe there is an alternative that can last longer?
Latex tubing
The pneumatic tubing
Surgical tubing is another good one
And these are all vex competition legal? nnniiiccceee
Latex tubing is your alternative and is legal in the identical size that VEX sells. I’ve found that latex tubing holds its stretch much better over time than rubber bands. The only disadvantage is that you’ll have to cut and/or tie it to make bands to use on the robot. I’ve usually taken the 5ft pieces, tied them into a big loop, and then doubled them a few times.
Here is the VEX product: Latex Tubing (10') - VEX Robotics
Here is an identical option we sell that is also competition legal and less expensive: https://www.robosource.net/elastics-latex-tubing/40-latex-elastic-tubing-10-ft.html
I’m thinking of doing a puncher. Will these alternatives be able to provide enough force? I’m guessing I’d be trading off force for consistency/reliability/longer lasting.
You can get just as much if not more force out of latex tubing.
Latex tubing does not snap as easily so you can pull it very tight. It will just require a lot of looping because it tends to stretch a lot farther than rubber bands
A team member just recommended bike tubing as a sort of elastic that can be used. Before we even start thinking about it, we want to make sure if it’s legal. Is bike tubing legal?
I don’t think VEX EDR includes bike tubing, and I didn’t see it on the list of non-VEX stuff you can use. VEX does sell rubber bands and latex tubing.
Latex tubing is an awesome choice that works really well for some teams.
I personally prefer rubber bands, but only a particular kind. I get alliance sterling size 64 blue bands from amazon, which can be found at this link The trick with these bands is you need to stretch them out a few times manually first, and then they’ll have very consistent stretch for the rest of their lifespan.
One last idea is something a friend of mine tried in SS. Basically you bend lexan but you don’t crease it, so you can essentially use it as a spring to push your mechanism towards a position where the lexan is straight. This only works for low force applications and very simple joints. I can attach a picture or video if that made no sense 
Anyhow, good luck!
I personally use Black Crepe Anglers off Amazon and they have lasted indefinitely for me. It depends on the quality of your bands I guess
@Inventor Inventor when we ran a puncher in NBN we had to calibrate tension all the time. However if you can I’d say build a bot and stretch your rubber bands like 250-500 times then calibrate using those, they should have practically no noticeable fall off. We normally use these on our lifts, but NBN on the puncher we didn’t have the space needed use so many older rubber bands without it rubbing on things and creating inconsistency.