Hi everyone, my team has been doing robotics for 2 years now and we are still struggling to build a capable drive-train. We're running with the Cortex system since our V5s don't come until the end of January. So, we still have a few competitions left with our current system. Our main problem is that we stall out quickly if we get in any pushing matches with other bots. We also have trouble climbing the platforms after an entire match.
In case the photos below don't show up
We currently have an 8 motor high-speed drive which is fine for most of the match except the conditions listed above. The motors were previously geared for turbo since we thought for sure we would be fine with 8 of them. After doing this it burned out if any amount of resistance was enforced. So, we switched to high speed. Although they work slightly better we still feel that we are doing something wrong. The rear motors are direct into the wheels and the front ones are chained to the front wheels. We've researched the PTCs in the cortex, power expander, and motors. We have the rear wheels in ports 2-5, front wheels in our power expander, and our catapult in ports 6-9 since it also draws a decent amount of current. We've read about teams with 6 motor turbo drives and they don't stall out so we feel we must be doing something drastically wrong.
So far we have two theories as to why the current design may be so inefficient. The first is that the modules are sagging which causes extra friction. And two, the metal on metal gears may be binding in certain situations causing the entire wheel to essentially stop.
We have two things we're going to try with our new drivetrain. The first thing is that we are no longer going to use the modules seen in the pictures. Instead, we are going to attach the motors directly to our C-channel to prevent sagging. We're also going to use plastic gears to hopefully prevent the binding with the metal gears. The picture below is a quick CAD model of what we're thinking about doing.
I'm wondering how you guys are managing to create such efficient DTs and if our new design is anywhere close. Thanks!