My team is considering using a pinching claw compatible with a 4-bar, and we were wondering: what mechanism should we use to fold the claw up before matches? We probably will use motors for the claw itself, but, completely extended, it’ll go past the size limit, so what kind of options do we have to pull the claw up that use a minimal number of motors and time?

what you could do is what our team is doing which is that we reverse the entire arm to hit the tower but in our case it would be the 4 bar

We made it so the claw opens up wide enough to fold into the sides of the robot.

a warning when using a 4 bar with a claw, we were using it earlier this season, but even using the longest (17.5 in) metal for the arms, the height was about 3-4 inches too short, just a warning when your building yours, you’ll have to bolt several pieces of metal together for the arm.

VEX sells c-channel couplers here just for this reason.

yeah, its not a bid deal, its just so you know

Why is that? Mount 17 in arm on a 17 in tower, allow 4 inches for overlap, and that’s 30 inches plus the length of the claw. The fence is, at most, 25 inches.

yes, but 4 bars cannot go straight up, due to how their made, it snot a big deal, just something you have to conisder when making your 4 bar.

17+17cos(30)-4 = 27.72 inches
I’m assuming 30 deg is max angle from vertical. And this still doesn’t account for the length of the claw.