FTC Null Robotics 8103 Relic Claw by AudreyTheAwesome

Last crawled date: 3 years ago

Hi! If anyone has printed this, and is using it on their robot (I've seen a few similar claws at play at Worlds right now, and have been curious if it was this one) we'd really appreciate it if you'd post a picture! It would be awesome to see it in action. Thanks!
This is the claw we (Null Robotics) designed for our Relic Arm for the 2017-2018 Relic Recovery season. It's accurate, and does reliable grabs. It also corrects for small amounts of error in alignment. Leaving the surface of the print smooth (rather than coating it with something that creates friction, such as plasti-dip) allows the relic to self-center when it is grabbed. The claw is asymmetric - the skinnier claw goes into the corner of the field behind the relic, and the wide one goes on the inside. Additionally, the asymmetric cuts out of the insides of the claws allow for the relic to be grabbed completely (arms and head), or just by the arms. Both grabs can carry a relic reliably, but the full grab is more so. However, grabbing by the arms is much faster and can be used for the second relic during the end game. It uses two 40-tooth Tetrix gears, and can be used with a servo on the end of an extending arm of some sort. The strength of the grab is as strong as the servo you use. I made this in OpenSCAD.
Here's it in action: https://www.youtube.com/watch?v=gib3fT9ozyE
Here is the chain tensioner: https://www.thingiverse.com/thing:3182477