Robotics Question of the Day!

[RyanCahoon]

Originally Posted by Nate Laverdure

Confusing to talk about increasing a ratio (e.g. 10:1) because it's unclear which quantity (1 or 10) you're increasing. Better to ask "How can decreasing a drivetrain's gear reduction increase its top speed?"

I guess I think about it as increasing or decreasing the equivalent fraction (10/1 in the case of your example). Maybe I'm wrong...

Originally Posted by 1502

When the gear ratio is too big for the wheel and motor combination. We experienced it this year. We put on a sprocket that was to small by accident and it would barely move. We doubled the diameter of the sprocket on the wheel and we were golden.

Right, I was pointing out that both are valid questions.

According to the Wikipedia definition at least, gear ratio is the ratio of the input speed to the output speed, so putting a larger sprocket on the wheel (or conversely, a smaller sprocket on the driving axle) would increase the gear ratio, creating a greater speed reduction. This reduces the theoretical unloaded freespeed, but, as I believe you're saying, can increase the top speed in torque-starved conditions.


Some other questions:
- Why is it important to keep electrical wires as short as possible? (Signal wiring and power wiring can have different answers, though there is overlap)
- What would be some advantages/disadvantages of using a smaller amount of a stronger but heavier material vs a larger amount of a weaker but lighter material (e.g. steel vs aluminum)

[Ether]

Originally Posted by RyanCahoon

According to the Wikipedia definition at least, gear ratio is the ratio of the input speed to the output speed,

So "low gear" in my car has a high gear ratio,

... and "high gear" has a low gear ratio.

That's probably where some of the confusion comes in.