What are gear ratios & torque?

Can someone explain gear ratios & torque to me, please? I’ve heard of it, but not totally sure what it is. I know that one gear is an idler & one is the input, but how does that speed up or slow down the robot? And where does torque come into the equation? Thx!

When you have a smaller gear driving a bigger gear, that slows down the output speed. When you have the opposite, that speeds up the output speed. Having a smaller drive a bigger gives you less speed, but on the other hand, more torque. Having a bigger gear drive a smaller gear, however gives you more speed but decreases torque.

Here is a link to a pretty good explanation.

@The Pioneers But what advantages does torque actually give you?

You are able to lift/move more weight, and have better acceleration (though a slower max speed). You can’t just use ridiculous amounts of speed on everything; it will stall and/or burn out. It’s all about pushing it as much as possible.

More torque gives you the ability to do more work. For example, if your drive base was 4 motors geared 1:1, you would be able to drive a heavier robot than if you were to have a drive base geared 2:1 (ratios written driving:driven).

@Aponthis Oh ok, I think I get it now. Thx a lot!

Yeah, no problem. Basically, if you have the same amount of power, and you triple speed, you will have one-third of the torque. You can’t speed up without any adverse effects. :slight_smile:

@Aponthis Got it. Torque good for lifting, speed not as much.

You generally want as much speed as you can get away with. Last season, our lift was 5:1 external with speed motors, which is still more torque and less speed than direct drive, but also reasonably fast.