[size=][size=]Team 3476: Code Orange Robotics presents our 8th creation, Gnaraloo.
Gnaraloo will be competing this weekend at the Orange County Regional and later on at the Aerospace Valley Regional.
W̶e̶ ̶u̶s̶e̶d̶ D̶o̶x̶y̶g̶e̶n̶ t̶o̶ ̶g̶e̶n̶e̶r̶a̶t̶e̶ ̶t̶h̶a̶t̶ ̶d̶i̶a̶g̶r̶a̶m̶. Doxygen is super useful, you can also generate extensive documentation and other diagrams with extra comment tags in a multitude of languages.
Our head programmer let me know that we actually used ObjectAid. It is apparently easy to use with Eclipse, but I would still heavily recommend Doxygen for its full featuredness.
In finals-1 we sheared the screws on the versa planetary disabling the arm. It is 3 stages plus an encoder stage. Not recommended. We also use a gear on the arm and based on the flex of the arm we should have used #35 chain.
We are changing the design to follow the vex recommendations; we will be a bit more conservative and go to 2 stages for the versa planetary.
…that would do it, though I’m not familiar with “shear the screws” failure mode? Which screws?
I’ve definitely mangled sun gears before.
We also use a gear on the arm and based on the flex of the arm we should have used #35 chain.
The #25 should be plenty strong for this - are you sure it’s the chains fault? I’d question the idler-based tensioning and any/all 1/2 hex interfaces first.
If I were setting up a chain run like that, I’d use a turnbuckle (such as WCP Spartan Tensioner) that holds tension in line with your chain run, rather than the idler sprocket drawn in your CAD that has to fight massive loads from the “tightrope effect”. Not sure what the technical term is.
We’ve noticed a lot of slop in the Vex 1/2-hex fit on Thunderhex this year… ended up bolting our “elbow” joint gear (72t 20dp gear) directly onto our arm, instead of transferring torque through the 1/2 hex bore to a versahub. Reduced slop/hysteresis by a factor of 5 or 10.