We went to our first competition with a new robot and a lot of teams were surprised that we could lift 2 MOGOS with only one motor, so, I ask the question,
what is the biggest ratio of MOGOS to motors you could consistently do? (MOGOS : motors)
yes, it’s definitely possible. most people use the double acting cylinders as single acting anyways, just with an external rubber band to close it instead of an internal spring.
Just make sure the thing is active clamp and spring release, because you need a lot more force to clamp than you do to release.
But how would that work with a mogo lift made out of single acting cylinders? Would at have to be on a pivot facing the other direction in order to lift it up?
well the exact geometry depends on what you’re using the cylinders for.
are you trying to make a clamp that holds a goal at the end of a lift, or are you trying to make some sort of forklift to hold and pick up goals into your robot?
yeah then you’re going to have to get a little creative with your cylinder placement.
consider this crude sketch:
when the cylinder (blue) extends, you could have either a cable, or perhaps a linkage (red) pull up on the forklift (grey), lifting it up on a joint.
a cube in tower takeover weighs 285 grams. Those huge dr4bs in tower takeover generally hold 10 cubes, so 2850 grams, or about 6 pounds. Lifting 7 mogos therefore isn’t anywhere comparable to lifting 10 cubes as it is 5 times heavier. Seeing that most teams that run a 10 cube tray typically had a 1:21 ratio, you’ll need at the minimum a 1:105 ratio to drive the lift. There will be tons of efficiency losses with 3 stage gearing, and with such a high load, the system will probably not lift and have other failure points that will break, meaning it most likely won’t work with just a single motor
you could certainly lift 30 lbs worth of goals with a single motor, though not in any way practical for competitive use. you would need ridiculous structure to support any sort of linkage, and the difficulty in acquiring 7 goals and placing them all on a lift would make lifting 7 goals at once with any amount of motors impractical.
I never stress tested the one lift I had, the lift was just a four bar but it could lift from the from or back, making the mogos weight counteract the mogos on the other side. It was built for two and probably could have held more. It used only one motor and was great, but it was just not right for what we wanted. :,( you will be missed