Wheels
Wheel diameter:
When buying (or making) your wheels you want to put your motor into consideration. For a start, there is torque and velocity. Large diameter wheels give your robot low torque but high velocity. So if you already have a very strong motor, then you can use wheels with larger diameters. Some motors already have good torque, so you should use larger diameter wheels. But if your motor is weak (such as if it does not have any gearing), you want to use a much smaller diameter wheel. This will make your robot slower, but at least it has enough torque to go up a hill! Another dumb mistake someone can make is buying a wheel that has a diameter close to or less than the motor diameter. For example, if you have a 1″ diameter motor, and a 1.5″ diameter wheel, you have a .25″ ground clearance ( (1.5″-1″)/2=.25″ ). How high is the tallest object you want to go over?
When buying (or making) your wheels you want to put your motor into consideration. For a start, there is torque and velocity. Large diameter wheels give your robot low torque but high velocity. So if you already have a very strong motor, then you can use wheels with larger diameters. Some motors already have good torque, so you should use larger diameter wheels. But if your motor is weak (such as if it does not have any gearing), you want to use a much smaller diameter wheel. This will make your robot slower, but at least it has enough torque to go up a hill! Another dumb mistake someone can make is buying a wheel that has a diameter close to or less than the motor diameter. For example, if you have a 1″ diameter motor, and a 1.5″ diameter wheel, you have a .25″ ground clearance ( (1.5″-1″)/2=.25″ ). How high is the tallest object you want to go over?
Wheel texture:
The texture of your wheel is very terrain dependent. A common mistake for beginners is to ignore the texture of the wheel. If your wheel is too smooth then it will not have much friction. This is a serious issue with omni-wheels(if you don’t know then please google it!). An all plastic omni-wheel works poorly compared to an omni-wheel that uses rubber for the side wheels. Overly smooth robot wheels would likely skid while accelerating and braking. However a wheel that is really rough, such as a foam wheel, has higher friction with the ground leading to innefficiency. You also need to consider wear and tear on the wheel.
The texture of your wheel is very terrain dependent. A common mistake for beginners is to ignore the texture of the wheel. If your wheel is too smooth then it will not have much friction. This is a serious issue with omni-wheels(if you don’t know then please google it!). An all plastic omni-wheel works poorly compared to an omni-wheel that uses rubber for the side wheels. Overly smooth robot wheels would likely skid while accelerating and braking. However a wheel that is really rough, such as a foam wheel, has higher friction with the ground leading to innefficiency. You also need to consider wear and tear on the wheel.
Wheel width:
You do not want it too wide as it causes increased resistance to rotating the wheel on a surface. I once used a 1″ foam wheel on a concrete surface and it was very poor at rotating.
You do not want it too wide as it causes increased resistance to rotating the wheel on a surface. I once used a 1″ foam wheel on a concrete surface and it was very poor at rotating.
Wheel center hole diameter:
This is where you would actually mount the output motor shaft to your motor. So you must know the length and diameter of your motor output shaft so that you may put this shaft into the hole of your motor.
This is where you would actually mount the output motor shaft to your motor. So you must know the length and diameter of your motor output shaft so that you may put this shaft into the hole of your motor.
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