[theawesome1730]

Originally Posted by Nuttyman54

I understand going to smaller wheels for weight, and lower speed for alignment, but lower gearing =/= more pushing power/torque in general. The amount of pushing power you have is directly related the the traction of your wheels. Once your wheels break free and start spinning on the carpet, it doesn't matter how low your gearing is, you can't increase your pushing power. For most FRC robots running 4 CIM drive at 150lbs (with battery and bumpers) and high grip wheels like the Andymark tread or blue nitrile roughtop from McMaster, this gearing limit is around 11-12 ft/s. At that speed, you will still spin your wheels on the carpet when you run up against a wall/another robot/etc., so gearing lower does not help your ability to push. Gearing faster than that, in general, will cause you to stall your motors before your wheels break loose. This is bad, and will blow breakers and overheat motors.

The exact gearing that this occurs at is dependent on the actual coefficient of friction of your wheels, the motors you're using in the gearboxes, and the total weight of your robot. This is why most teams that do 2 speed gearboxes run around 5-7 ft/s in low gear and 15-19 ft/s in high gear, giving them one traction-limited gear that will accelerate well and won't stall the motors in a pushing match, and one high-speed gear for getting around the field quickly.

The good news is that at 2.3 and 12 ft/s, both of your gears will probably be traction limited, so you're probably not at risk for stalling motors. They're fine speeds for driving around the field and for precise alignment. Just don't be fooled into thinking you get more pushing power out of the low gear. Unless your high gear stalls the motors before the wheels spin, they will both have the same amount of pushing power.

Our coefficient of friction on the VEXpro wheels is 1.2 which is higher than most others and our weight full loaded will be around 175 meant around 150. I can't think right yet. I haven't recovered from build season. (putting weight in bumpers to use as a counterweight)