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I have two identical box designs with EV3 bricks. When I upload the same programs to both, one moves about twice as fast as the other.

Is there a reason that this might be happening? Is there anything I can do to update it?

Ambo100
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Lori
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    Have you checked the batteries? Maybe one has almost-dead batteries? – Alexander O'Mara Nov 20 '17 at 19:45
  • I have fully charged both batteries and they are both reporting full batteries. I will try to swap out the batteries but right now it's not easily accessible from the design I've got, so I was just curious if this was expected or not. – Lori Nov 20 '17 at 19:59
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    Can you post your program, or at least the part with the Move blocks? – David Lechner Nov 20 '17 at 20:11
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    It's noticeable on a standard steering block - say at 75 power and going for a few rotations - on one brick that move may take a second, on the other, 2 seconds. i'll run and time it later today and post specific times, wheel diameters and rotations. – Lori Nov 20 '17 at 20:53
  • Are you sure the problem is with the ev3 bricks? Have you tried switching the motors? Maybe one is defective? – Phil B. Nov 21 '17 at 13:18
  • I didn't swap the motors, but if one of the motors was defective, on a tank steering block I would expect that if both motors were at the same power it would turn because one motor would be outputting power at a different level. Given that it goes straight, it would mean that both motors are sending the same output. – Lori Nov 21 '17 at 13:29
  • Is it possible you have more tension or friction in one of the builds? I assume that you've got some gears, etc in there - are they all able to spin freely, or are some of them clamped a bit tighter? I agree this is probably unlikely based on your comment about "tank steering" as that would required the two sides to be equally stiff. – Zhaph - Ben Duguid Nov 24 '17 at 15:08
  • So it turns out the issue was a bad rechargeable battery pack. When I replaced with fresh batteries the robot performed comparably to the other. – Lori Dec 02 '17 at 00:39

1 Answers1

2

Some possible reasons:

  • A motor is defective
  • One of the brick has lesser battery charge
  • Firmware problem: make sure both bricks have latest firmware
Vikhyat Agarwal
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