Cargo Intake RPM

Hi everybody! We were wondering what RPM other teams were either using or planning to use for their cargo intake. Additionally, if there was any particular way to figure out what RPM would be best. I’m familiar with the JVN design calculator, as I used it last year while designing our team’s climbing mechanism. However, I was wondering if there were any other particularly helpful resources out there or things to consider for this sort of thing. We’re planning on using 775 Pros.

Also, separate question: what are other teams getting for the weight of the cargo?

Thank you all so much in advance!

A common rule of thumb that I’ve seen around CD is to gear your intake such that the surface speed of the roller is roughly twice the speed of your drivetrain. I’m not really sure why this gets tossed around so much and what testing went into supporting this idea.

The best way to figure the ideal speed for your intake is to test as many speeds as possible. Your robot is different than everyone else’s and perhaps a different speed will work better than the rule of thumb.

If you have versa planetarys you could easily test a wide variety of speeds and get some solid data. If not, you could simply supply less voltage to your motors to reduce their free speed. Intakes generally (not always) require little torque so testing at a reduced voltage to gather data and then gearing down at full voltage should provide pretty similar results.

If you’ve got any other questions about prototyping or designing this kind of mechanism I would be happy to help however I can.

This is said so often because if your intake is twice as fast as your drivetrain, even if your robot and the game piece are moving in opposite directions, you’ll still intake it assuming you’ve made contact already.

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That makes sense. Thanks for the clarification. Do you know of any videos or papers detailing the process of teams testing this? I’d be interested to see how the ideal intake speed changes based on the size, shape, and mass of game objects and if things like mechanism geometry make a significant difference.