Arm locks for a RI3D based robot

I am working on a lock mechanism. Im doing this based off the goofy documentary-RI3D. I couldn’t figure out their locking mechanism but would like to know how to fix this or work a new locking mechanism i also considered a dropping lock screw holding it in place. I need to keep it from going in the path of the cube holder.image

the documentary explains the locking mechanism pretty clearly, better than I could anyways. you may also want to consider doing top down deploy, it isn’t quite as fast to deploy, but it’s easier and provides better compression as you don’t need any locks.
you could also try having small 4 bars mounting your intakes to your arms, I’ve seen a few bots with this working successfully.