What would be the best kind of drivetrain for override? Any thoughts?

VEX V5 Robotics Competition V5RC > Override (26/27)
1

Does anyone have any thoughts or recommendations on what drivetrain (including types of wheels like mecanum or omni or track etc.) would be the best for override? considering the 55 watt limit.

2

It depends on how the game is played. If stacking as many as possible is the most important, the faster the better. If it’s pushing then more torque. It is, unfortunately, too late to say.

(Also not mecanum, unless vex releases new ones. They probably will not be good at all. Generally, way too thick and large)

3

I think that considering that mobility will be important in this game and also the 55 watt limit, the mecanum drivetrain sounds like a good idea to me

4

I was thinking omnis with probably traction wheels in between because of the endgame pushing battle. I’m probably going to run 360 or 450 55w drivetrain though.

5

My team is just going to keep it simple with a 44 watt drivetrain. 4 omniwheels and 2 traction to help with pushing at the end. All ran at 333 rpm on 3.25 in wheels

6

We are going to try a 55W with two full and one half motor on each side.

7

400 rpm 3.25 or 450 rpm 2.75 will be the best drive designs. They have similar linear speed and will be the best balance of acceleration and speed with the new motor limit. I’m leaning towards 400 rpm 3.25 though because it’s a bit easier to build longer at the cost of doing some motor stacking tech

8

anyone think mecanum dt would be good?

9

or maybe even an x drive

10

I agree with the assumption that higher speed drives will be better. This game just doesn’t rlly need a slow drive because you need to score and have very few alternatives to it.

11

I don’t think mecanum will be that good for the same reason it isn’t for vex. The vex mecanum wheels suck. Unfortunately.

I also don’t think X will be good, because it’s just very heavy and you have a reduced pushing power (22w instead of 44w/55w. Which although i don’t believe will be too important, it’s still something to consider)

12

My team is planning on doing a 44w x-drive, mostly for the added maneuverability, and the fact that most of our team wants to do an h-drive or an x-drive and the rest of us are very against an H-drive : )

13

For this game x drive would be overshadowed by other drive like the tank drive (or maybe even an H drive). In my opinion.

14

So having done all of these here is some pros and cons that I would recommend considering.

H-DRIVE

Pros: Acts very similary to a tank drive, allows for strafing, fairly easy to code.

Cons: If the 5th wheel is not under the center of mass the robot will make a wide arc instead of going side to side, easily susceptible to pushing because of only being omni wheels, 5th may not always be touching the ground because of weight.

X-DRIVE

Pros: Wide range of mobility, fast in all directions, great for aligning.

Cons: Lowered pushing powered compared to most drivetrains, can be difficult to build and code.

MECANUM DRIVE

Pros: Closest to a tank drive, allows for strafing, pretty easy to build.

Cons: Coding is a bit harder, turning can be slower, wheels have to be aligned the right way when built.

TANK DRIVE

Pros: Most basic drive, maximum pushing power of the options, can use the 44 or 55 watt limit depending on needs, easiest to build and code.

Cons: Decreased mobility, Unable to strafe.

Hope this is helpful and if there is anything I missed, I apologize.

15

thanks! this was very helpful. out of curiousity, how would you rank these from best to worst?

16

I think I would have to put it in these rankings

1. Tank drive

2. H drive

3. X drive

4. Mecanum

I put tank at the top because it is so versatile and very simple to do. And is very consistent.

H drive in second because you can have most of the benefits of a tank drive and strafing, with a bit more difficulty.

X drive is the best at movement in all directions but can defend against the two above and is more difficult to do. However there are good x drive that can be better than h and tanks but in general they tend to be worse.

Mecanum is good but h drive in my opinion is more consistent and closer to a tank drive. Mainly I have seen better x drives in the past than I have seen mecanum drives. Also the wheels take up a lot more space in the robot.

17

agreed @Nosypoke @Hg1yt, but it can also come with risks. driver would need to be really good to not make violations.

18

ohh I see. that makes sense.

I was also thinking there are pros and cons to a faster drivetrain. for example, a faster setup can be more maneuverable, but it also comes with less control and a higher risk of bumping into field elements or knocking things over. in some cases, that could even lead to violations depending on whats disturbed.

19

Transmisson tank drive will be awsome

20

@Logan_96428S do you think a split arcade omni + track dt would be good?