[BJC]

I can't find the original spot on the internet where I got them but JVN's design calculators will allow you to figure out exactly how an arm/intake/elevator/drivetrain will perform with specific motors/gearing. I highly suggest anyone who hasn't seen them before saves these somewhere safe for the build season.

Balancing an arm can do nothing but improve its performance. Team 33 always springs our arms/elevators up without exception because it is *better* then it otherwise would be.

*Goes faster, lifts more, pulls less current, makes it easier to maintain a selected position, etc.



Edit: Answering the OP's actual question.

Brandon: Gas Springs are awesome in certain situations. Team 67 is the most noctorious for having some crazy powerful gas spring "thing" on their robot. 2012 they used gas springs to hold up their "arm" in the collecting position. That said, big gas springs are also pretty heavy. Surgical tubing can also work really well if you do it right and weighs very little. The biggest factor with surgical tubing is:

1. The lever arm. Depending on where the tubing is attached relative to the pivot point it will change how much force is being exerted on the arm. This will determine how much surgical tubing you need. Thankfully, because surgical tubing is easy to work with and change the amount can be experimentally found in testing.

2. The stretch distance of the surgical tubing when the arm is fully up vs. fully down. By minimizing the difference in length you can get the force on the arm almost constant throughout the arm's travel. The longer the sugical tubing and the shorter the lever arm the less change in length there is.

If you're running a linkage arm, you can also put your surgical tubing between the pivoting points on the linkage.

I don't know much about using gas springs as counterforce so I'll let someone else take that one.