Your Thoughts on H-Drive Drivetrains for FTC

Technical Technical Discussion
1

I was wondering if anyone had opinions on H-Drive drivetrains for FTC.

If you don’t know what H-Drive is, imagine a standard tank drive using omni-wheels for all the wheels and place another omni-wheel in the center of the robot perpendicular to all the other drive wheels. This allows for holonomic drive to be achieved while still offering some of the pushing and power advantages of tank drive.

For whatever reason I see nobody use this system in FTC, even though it needs 3 motors to have independent control instead of 4 motors like mecanum. It seems strange to me that, despite H-drive’s cons and the usually “no defense/pushing robots” rules of FTC, nobody seems to use it and instead opts for mecanum.

Any thoughts on this? I was thinking of designing an H-Drive chassis for next year’s FTC season (if the game next year makes it viable) but want to know if there are any specific reasons teams seem to avoid it.

Also, if any Hawaii FTC teams see this, good luck and have fun at tomorrow’s FTC Regional Tournament! Let’s make a ‘Ruckus’ tomorrow! :cool:

2

I have actually seen FTC and VEX robots use H drive, the biggest problem with it is that it takes quite a bit of additional space in the frame. Mechanum drive leaves the middle of the frame open for any mechanisms or electronics you may want to use.

3

Mecanum is simple and works really well on the floor tile.

4

This is generally the biggest reason. The other is that it’s generally a challenge (not impossible, just a challenge) to get all five wheels to apply the right amount of pressure to strafe.

But, if your design absolutely positively needs strafing and five motors on the manipulator, you gotta do what you gotta do. :slight_smile: