As a team who has utilized a mecanum wheel powered base at our state championship, we found that mecanum wheels had practically no strafing functionality once one or more mobile goals are possessed. To be fair, our base was geared up to 280 RPM, so the mecanum wheels may not have had the torque to strafe as effectively.
So, I was curious about other teams who have attempted to use holonomic drives, whether it be an X-drive or a mecanum wheel drive; how efficient could a holonomic drive hypothetically be at strafing in optimal conditions while carrying mobile goals? What would need to be done to make the strafing efficient?
One idea I had was creating an X-drive with 2.75" omniwheels and 200 RPM direct drive; I was thinking it would hypothetically have the torque to drive in all directions normally while possessing mobile goals, but I was curious if you guys had any input regarding how much torque is actually necessary. Perhaps using 2.75" wheels is overkill and 4" wheels would be enough. I don’t know.
And a small disclaimer: yes I’m aware holonomic drives have extreme tradeoffs in Tipping Point compared to something like a 6 motor tank drive. I just like holonomic drives a lot.
Mecanum wheels are especially susceptible to center of gravity issues, probably more so than other types of holonomic drives. So when you pick up a mobile goal on one side of your bot, you make a big change to the center of gravity.
That’s what I was thinking; do you think this problem is as significant when it comes to X-drives?
standard x drives should have the same force moving sideways as forward and back.
I think holonomic drives could have some merit for very high level programmers looking to do really way in skills at worlds, but other than that I don’t see them being worthwhile. Pushing and climbing are very important this year, and holonomic drives aren’t so great at either. There aren’t any specific situations this year either where I find myself wishing I could strafe, considering that in a successful match, you spend most of your time not moving at all.
I have seen holonomic drives climb, however their driving speed was extremely slow which is a huge disadvantage. Like Xenon said the only reason a holonomic drive would be helpful would be for autonomous skills. This year the advantage is speed and this just isn’t offered in a reasonable manor. Smart driving with a tank drive will diminish the need for a omni directional drive like an x-drive or holonomic drive.
I love x-drives also! For most of the year I’ve been using a straight 200 rpm x-drive on 4" wheels and I have no problem strafing at all with multiple goals. Like the posts above have said they aren’t great at climbing or pulling/pushing but I just love the movement they offer. It’s also gotten me out of sticky situations where I’ve won because I was able to easily re-adjust the way I put the goal on the ramp.