How do I put 20 motors on 1 robot?

Technical Electrical
1

I’m working on a project for my robotics team where I need to connect 20 motors to one robot. How would I do this? (We use kraken x60)

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2

The Rev PDH has 20 slots total, so as long as there is nothing but motors that need power they can be connected. The second issue you’re gonna run into is power draw though. Batteries are going to die extremely quick. If you don’t need quick acceleration or high torque you can mitigate this, not fully but minority, but putting very very low current limits on each motor used.

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If I am wrong anywhere, please correct me

4

How would I counter the battery drain?

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The only way to really limit battery drain is only to limit how much you use the motors and how much current they draw. In programming you can give the batteries current limits, and also just design for efficiency.

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6

RIP the battery

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7

Just don’t run all of them at once. Having 20 motors doesn’t mean you need to be constantly spinning 20 motors.

Also, you have to connect 20 motors to a robot? Why? Do they all have to do something?

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If this wasn’t an all Kraken bot, you could link in parallel 2 750(?) motors to a single controller, this is what House of Cards did for their 4 sided intake.

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9

we need the 40 motor robot

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10

Really really low current limits for each motor.

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also just using new or less depleted batteries will help you

12

This is a solid point. You can run 40 motors as long as they’re the ones listed below. Not sure I’d recommend running any of those anymore though.

image

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13

Extending this very relevant question:

  • Do they all have to do something independently? Is it feasible to use one motor to spin two shafts, for example?
  • Are you unnecessarily using multiple motors to make one movement? If you have two motors on an arm, or an elevator, or a winch, can you achieve your design goals with one? I believe there are many times that torque and speed calculations are not done and two motors are used because someone has seen a team use two motors in the past.
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If it’s for non-competition purposes, you could run multiple batteries (preferably with similar charge levels) in parallel to run it longer. We have a T-Shirt cannon robot that we run with two batteries like this to extend its range (we run it along a >1 mile long parade annually).

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What if you don’t compete with it…
Now you have no rules…
Also what purpose do you have Putting 20 krakens on a PDP any ways?

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If this is not a competition robot, you are not limited to a competition legal battery.

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17

Sure, then just add another PDH and battery. Or switch to lithium ion (and probably burn your shop down).

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Why is this surprising? We had 17 motors on our robot this year, and I count 19 Krakens on 254’s robot:

  • swerve 8
  • intake 1
  • feeder 2
  • turret 1
  • shooter 3
  • hood 1
  • amplifier 2
  • climber 1
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19

Did the swap already. Shop still stands.

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20

I know it’s been done, but why does the OG poster team want it done? To test amp draw, battery life, etc. What is the goal.

1 Like