what was the best shooting mechanism for 2016?

[electroken]

Originally Posted by 1493kd

Thanks I had already read that post, I was wondering if you had any additional information and pictures.

This side view shows the catapult arm after it has reached its most forward position and has begun to retract:



The arm is nearly the length of the robot and pivots on the front frame rail. It's driven by 2 mini-CIMs through a toughbox mini and #25 chain with an overall ratio of 28:1. We have an incremental encoder on the gearbox so we know how far its traveled is each 20mS control loop.

I don't remember the exact weight of the catapult arm but it is extremely light. The arm itself is 1.25" square, 0.040" wall thickness 7075 tubing that came out of a sponsor's dumpster. The "dish" the boulder rests in is carbon fiber. The block of pink foam on the arm was added after week 3 and reduced the boulder settling time substantially.