1:1?

I am confused on how the gearing thing works.

People say 1:1:2 or something and I don’t understand what that means…
Or Geared 1:1?

What’s that stuff mean?

That is how gear ratios are described. I could explain it here, but this article will do a much better job: http://www.howstuffworks.com/gears.htm

I am still confused.

Could you explain it?

Sorry, I have not understood this for a long time.

thanks

Ok, say you have a 12 tooth gear being driven by a motor, and you connect a 36 tooth gear to the 12 tooth gear, then your gear ratio is 1:3. It’s the ratio of the input gear tooth count to the output gear tooth count. The ratio is usually simplified to small integers that are easy to visualize.

It is actually the opposite. The gear ratio is supposed to be based on the number of revolutions, so it would be a 3:1 gear ratio. In order to be specific as to whether it is geared for speed or geared for torque, I always simply say which it is, to avoid confusion.

Just think of it as the number of teeth on your driven gear (the one on your wheel, or on your arm) over the number of teeth on the drive gear (the one on your motor). Just as “magicode” said, if you have a 12-tooth gear on the motor, and a 36-tooth motor on your wheel, it will be 36/12, or a 36:12 gear ratio, which can be simplified to 3:1. For every 3 turns of your motor, the wheel will spin 1 time.

~Jordan

I’m sorry, I guess you’re right. I always get the order of the ratios backwards.

Jordan is right in that 12 tooth to 36 tooth should be 3:1 in the real world. However, a lot of people in the Vex community (myself included) have gotten it the wrong way around for so long that it’s often a guessing game as to which they mean (of course you can say geared for speed or torque as Jordan says).

Basically, turn the ratio into a fraction.
What you’re mostly interested in is how much of a ratio there is - 1:1.2 is not as much of a change as 1:7.

It pays to try to understand what context the gear ratio is being used in, so you can make a judgement on what they actually mean.

When we say “geared for torque”, basically the robot will move slower but have more “pushing power”. When we say “geared for speed”, it’s the other way around so the robot will move faster but have less ability to push things.

So let’s say for example that someone tells you that the gear ratio on their arm is 1:7. This evaluates to 1/7. You can also infer from the fact that it’s being used on an arm to guess that it’s been “geared for torque”. This means that they used a smaller gear on the motor to turn a bigger gear, giving it more torque but less speed.

Another example is if someone says that they used a 1.67:1 gear ratio on their drive train. This evaluates to 5/3. In general, most gear trains are 1:1 or higher because most teams want to gear them for speed (there are of course, exceptions). This means that a bigger gear on the motor is being used to turn a smaller gear, giving it more speed but less torque.

Hopefully that helps! :slight_smile:

1:1 usually means direct drive. Or a 36 tooth gear to a 36 tooth gear, basically any ratio that if you simplify it it turns out as 1:1. Such as 12:12, 36:36, 60:60, 84:84, etc.

In almost all cases related to VEX, you will see it this backwards way, so on the forum it’s easier to just do it backwards and people will know what you mean. However it never hurts to specify by saying “for torque” or “for speed”.