Our team is working on climbing ideas and we are currently leaning towards using a linear actuator type thing to lift up the front of the robot. I was wondering if the DART actuator that’s on Andymark (https://www.andymark.com/products/dart-12-in-actuator-kit is legal in this year’s guidelines. We figured that it is because it uses a CIM motor however I’m not sure if I missed something while looking through the manual.
The big thing is that the motor used (in this case CIM) is legal. There are no rules which limit gearboxes (counting a rack as a linear gear here), other than the general fabrication and safety rules which apply to all robot parts. You could also use the DART gearbox with a mini-CIM, NEO, Nidec Dynamo, CIMulator, or VersaPlanetary with CIM output shaft if you wished.
We used two DARTs in 2016 to lift our arm and it resulted horribly. It got to the point where we had to rebuild them every one to two matches it seemed like. We ended up replacing the bottom mounting plate with a massive bearing that could take the thrust load a lot better. Once we replaced that (it was worlds when we finally discovered a solution), we never had an issue again.
We used a dart for our arm last year including a portion of our climb routine. If you follow the instructions and don’t exceed the specifications for loading they are a really nice product. Just don’t try to make it do more than it is designed for, and it should work just fine.
The arm weighed quite a but and the linear actuator wasnt the best application really. We noticed any sort of shock load (hit defense too hard, ran the arm into a wall, etc.) would require a rebuild. We also noticed that the linear actuators (we had 2 tied together at the top on the arm) would bind if they got out of sync at all really.