Mecanum Drive w/ 2 Wheels?

I am currently designing a robot with a mecanum drive, 4-bar, 2 side rollers, and one central roller at the end of a tray. I currently have:
4-motor Direct mecanum drive
2-motor 7:1 4-bar
Both side intakes with one motor each

However, I don’t know whether to change to a 1 motor lift or, if possible, a 2-motor mecanum drive. What should I do?

A two-motor drive is useless on a mecanum drivetrain. You need to have a four-motor mecanum drivetrain in order to utilize the capabilities of the mecanum wheels.

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I don’t think it is possible to make a 2 motor mechanum drive.

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Well it is but then you wouldn’t be able to you the strafing abilities.

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Exactly, it would be like having giant useless wheels.

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Ok so should I go with a 1-motor lift? I am trying to lift a tray with six balls max.

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A one-motor lift is possible, you just need to make sure you have a good gear ratio to go with it to provide enough power.

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Yes. All of this is very light. You can look at examples people have already made

Yeah tons of teams with traybots had one motor lifts. You will easily be able to find examples from Tower Takeover.

One good example of the lift from 46535k. I sorta know the people that made that robot and they have good build qualities. They are very good so you could go with something like that

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Ok thanks for your help.

Yup. You should easy be able to achieve this and there are many different ways.

For the lift, I personally would use the high torque motor, high strength shafts, a gear ratio that gets the job done, make the tray almost 100% aluminum, don’t use screws that are too big, use nylon nuts here and there, and FINALLY try and make the tray as bare bones as possible, holding the 6 balls with the minimum amount of metal that is.

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It’s common practice to make lifts as light as possible to optimize the use of metal, but the weight of the lift doesn’t really have an effect. This is because with proper banding, the weight of the lift and force of gravity are accounted for, and the motor is only lifting the added untuned weight, in this case balls. Being as balls this year weigh almost nothing, you can definitely use a 1-motor lift.

I wouldn’t recommend any less than 4 motors on a drive.

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Weight still has a significant effect even when the lift is theoretically “perfectly banded” Even if the force of gravity and the force of the bands cancel each other out, it will still take force to actually move the lift and the heavier it is, the more force you need to move it at the same speed.

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Yes, in one way, it’s preferable to have a heavier lift, as objects being lifted will have a smaller percentage effect on the lift’s weight. In another way, it’s preferable to have a lighter lift, as a lighter lift accelerates more quickly. It’s about finding the balance.

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