Team 2980's Open Source FIRST BOT

[DavidGitz]

We are using an arm that weighs (I would guess) around 15 lbs including our gripper that is about 6 feet long total with 2 window motors and a 4.8:1 ratio and 2 heavy duty rubber straps to counter the weight. Our arm takes about 4 seconds to go from the bottom position to vertical. On Saturday we were noticing it was taking longer for the arm to rotate up but thought it was because our gripper was extended out and making it harder to lift, turns out one of the denso couplers had cracked and only one window motor was lifting. It was good to see that one window motor could do the job (barely). Since then we have "upgraded" our denso couplers and they seem to be holding up better (that was the 2nd one we cracked this year).

I haven't watched any video of your robot, so this could be irrevelant but I would make sure to check that the window motors can lift your arm fully extended. Our arm weighs about half yours and we have over twice a gear reduction.