My team does not have pneumatics kit and has tried multiple different ways to built a mobile goal clamp that can still hold the mobile goal in place without pneumatics. We have used a gear ratio with a green motor to try to achieve high torque to keep the mobile goal in place but it just keeps slipping.
All ideas are welcome and pictures would be amazing!
You are on the right track - you can use a high torque gear ratio for your green cartridge, then determine what position works best to hold mobile goal… It is up to you to determine what parts you have to clamp - c-channel parts, rubber bumper feet, etc whatever you are comfortable using.
In terms of coding, you can configure break mode for your clamping motor to be coast, break, or hold. Each are documented in VEX library.
No one can tell you what to build as you only know the parts you have, and experience to research at your team’s ability.
We have a prototype that works okay but we are trying to make it so that are clamp works really accurately every time.
We will definitely work on our code and try to recreate different modes for the clamp like you suggested. Hopefully the code works great and our robot works well for our next tournament.
Another resource for motor clamps I want to throw out there is the BLRS 2 tipping point dizzy explanation. I will attach a link, and I believe it is explained at 1:30 in the video. Hope this helps! Video here
I would recommend building a locking clamp that uses a motor. This will save your motor from overheating and will hold the goal in just as well as pneumatics.