High speed construction?

VEX V5 Technical Support UNOFFICIAL Tech Support
1

Just wondering, how would you make YOUR robot go really fast?

  1. How would you gear it?
  2. Which motors would you use?

Thanks!

2

Use the high-speed motors, all four of them on a drive system, direct drive.

OR

You could add two standard motors geared up, or you could have six regular motors geared up…

One thing to keep in mind is the torque… While you might move fast, you want to make sure you can still win at least some of the pushing wars that will inevitably happen.

3

Things you can do to increase speed:

  1. Design/Re-Design a light/lighter robot
  2. Design/Re-Design a small/smaller robot
  3. A key factor is having low and centered weight distribution, lower center of gravity
  4. Use the 393 motors, either in high speed config. or in normal config. depending on the following:
    - Weight
    - Wheel size/type
    - Gear Ratio (1:1, 2:1, 5:1, etc.) and type (gears, chain and sprocket, etc.)
  5. Find the best gear ratio for your robot dependent of #4
  6. USE MORE NUMBERS OF MOTORS, if possible, if not, design/re-design
  7. Make sure you use your bearings accordingly and don’t over compress the collets on the shaft, you want them to HOLD the shaft in place, BUT NOT INCREASE more friction

Finding the best speed:

  • make sure your motors don’t stall, it is best to run them at their most efficient speed and torque
  • you can run your motors at its most efficiency by doing #4 and #5 above
  • look at the motor spreadsheet that tells you information about the motors

This here, helped me, but I don’t know if it’ll help you:

  • this small but painful thing that I found to do is: if you have more than enough motors, test each one and look for the best running ones, I solved my robot’s problem of one side moving faster than the other with this and it improved my speed a bit
4

four HS motors (speed up) : that would give you a 1:1.6 ratio already
and gear/chain/direct 1:1 on 4" wheels
this would give controllable speed with high enough torque to support a heavy robot or for pushing other robots

5

Quote: “high enough torque to support a heavy robot or for pushing other robot”

I remembered at one point I tried 8 normal motors, 1:1 ratio, with a ~12 pound robot, it has good strength, and worked very well, but despite the 8 motors… it was still not able to push other robots. I don’t know what people are talking about pushing robots. Most I’ve seen is a bump or ram, that displaces robots like 3 inches.

Care to show me a video or something, I really want to see, learn something new everyday. =D

6

my current bot has four regular 3 wire motors directly driven and uses clutches. the bot weighs over 20 pounds and can easily push things around. try spreading the motors across the motor ports and/or using a power expander to maximize current flowing to the motors (eg. right side of drive in 2 and 3 and left side of drive in 8 and 9) see if that helps at all.

7

I would take the wheels off, support the frame in a sturdy box, and check it as luggage on a plane to Florida. Top speed should be > 300 MPH. Its not permitted to drive it forward through the aisle of the airplane, although that would make it go marginally faster.
Other than that, MY robot is has already carefully balanced the engineering tradeoffs of speed, power, traction, capability, and reliability in order to maximize its performance metric.

8

Thank you all, we’re considering to use HS motors configured to speed and gear it to speed, we’re just making ours a defensive hanger XD
(for worlds)