How many inches does my wheel go in one rotation?

[MorbidAngel]

Okay. I'm trying to program for autonomous, and we're using the encoders. I don't understand how to find out how to get how many inches one rotation of the wheel is. The diameter of the wheel is 3.75 inches. can anyone help me with this?

[Branden Ghena]

So, if you look at this problem geometrically, one revolution of the wheel means moving a distance equal to its circumference. Therefore, on a 3.75 inch diameter wheel, the distance it travels in one rotation is equal to its circumference, 3.75*pi which is approximately 11.781 inches.

[LordRed]

The way we determine that ratio was to run the robot for a 5 or 10 seconds in a straight line and measure the distance traveled. Then we divide the distance by the number of "encoder ticks" for that run.

[MorbidAngel]

Wow thanks guys ^^
I feel stupid now hehe
thanks for the help
peace

[billbo911]

Additional input.

Take the distance per revolution, divide it by the number of ticks from the encoder per revolution of the wheel and you will get your distance per tick. With that information, you should be able to per determine how far to travel based on the number of ticks you desire.

[MrForbes]

Considering what time of year it is, make sure you use the correct value for "pi"

[kramarczyk]

Originally Posted by squirrel

Considering what time of year it is, make sure you use the correct value for "pi"

I would suggest carrying out pie to more places.

[David Doerr]

Originally Posted by kramarczyk

I would suggest carrying out pie to more places.

I think you meant more pieces. Yes?

[billbo911]

Originally Posted by squirrel

Considering what time of year it is, make sure you use the correct value for "pi"

Here is an alternate value for "pi". All of these yield the same result.

[Kevin Sevcik]

Originally Posted by billbo911

Here is an alternate value for "pi". All of these yield the same result.

Just make sure you're not using too coarse an approximation of "pi".

[ericand]

Hey, That Pi R Square'd

[Lowfategg]

Now I am hungry.

Thanks guys.....

[GaryVoshol]

Which brings up this old joke. A hillbilly finally sent his son into town to go to school, rather than relying on the old McGuffie Reader at home. In math they were studying geometry, the area of circles. But the boy didn't understand something. The teacher kept saying, "Pi R squared." The boy said, "Pie are round. Cornbread are square."

[JM987]

ah.
those are some pretty small wheels.

[MorbidAngel]

Wow, you guys are stupid. Get a life.