Quote:
Originally Posted by KrazyCarl92
You're right, thank you Adam. I meant 1.0 lbs/10 feet for #25 chain and 2.5 lbs/10 feet for #35 chain. That makes the difference in weight on the whole robot only about ~1.5 lbs.
I'm not sure what you mean here. I didn't talk about "torque loss" at all in my previous post.
If you want to know the max amount of tension possible in your chain is, a quick and dirty way of getting there is:
Take your robot's weight. Multiply that by your wheel's CoF on the playing surface. Now multiply that by the ratio of your wheel diameter to your sprocket pitch diameter, making sure you use the same units. Divide by 2 because each half of a tank drive is assumed to support half the weight of the robot.
Tension_max = Mass * CoF * D_wheel / D_sprocket / 2
This will tell you the necessary tension in your chain to make one of your wheels slip when it is supporting half of your robot's weight. Now in reality, one wheel will not be supporting half of the weight, it will be distributed among multiple wheels on that side of the robot. And the wheel that most commonly supports the majority of the weight of the robot will be the one directly driven off of a gearbox on a WCD (your dropped center wheel). And since you have a dropped center direct-drive wheel in a WCD, it is not necessarily a crippling issue to toss a chain.
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Sorry, I think I got mixed up on who I was replying to haha. But my question was do you have to account for the size of the sprocket when calculating torque loss? I would guess not as the majority of force is applied on the wheel.