will it be more beneficial to use one or two wheels in the middle for the H- drive
I personally would recommend one wheel with two motors powering it, This takes up less space so it is easier to fit in other mechanisms
I would recommend 2 wheels, larger, but will allow for strafing without advanced calculations of the center of mass of the robot
Two motors and two wheels all geared together compactly on 4" omnis looks like a pretty solid from our 81C team this year. Sorry no pics. Just a drive train at this point, not fully built. But promising!
It would be benificial to use two wheel to accurately balance the robot
I would recommend an X-drive rather than an H-drive. An X-drive uses all the motors all the time, whereas an H-drive basically splits your power. Inefficient, huh?
i don’t think that that a x - drive is really ideal for this game this year, where a tank drive, has space at the front for intakes, and really strafing this year is not worth it
Definitely. I’m just saying, if you are making an H-drive, an X-drive is better.
h drives are not worth the time and effort put into making, it is just dissapoinment ahead.
That’s pretty much what I’m saying, yes. Can’t say I feel THAT strongly about it, though.
Trust me i know the struggle…
He is right, my team spent so long building an h drive and it sucked. Then we built a 6 highspeed motor tank drive and it is infinitely better
agreed, we have 6motors tank drive inste and it is much better
We are all over the drive base universe this year. One team has gone X drive with an octagon base. One has decided that the + drive is better because of the way their manipulator works. Another has a hybrid 6 wheel (omni, omni, traction). Another has a standard 4 wheel drive base, but has the little traction wheels about 1/2" above the surface, al la Big Daddy Garlits.
Drive bases all have pros and cons. I don’t share VEX 2.0’s disdain for H drives, I’ve seen very successful teams build and use them.
Competing on 9/24 I noticed that having an H-Drive (slow one at that but functional) was very very helpful. Realistically it’s up to the driver on whether or not to have an h drive. If you can maneuver your way into tight spots then there is really no need for it, but I personally found it nice to have. As for the X drive, that is more efficient if you are consistently moving in ALL directions. It has something like 58.6% efficiency (correct me if I’m wrong) in any given direction because of the angle of the wheels. If you are going to go in all directions frequently then an X will be best. However, if you are mainly moving in one direction and then occasionally strafing in the other, I do believe an H would work best with less motors in the direction that is traveled less.
If most of you guys are using 6 motors anyway how about a Asterisk drive. it has the torque of a 6 motor tank drive but it would allow you to strafe too using 4 motors instead of 2 motors on a h drive.
Not sure how the two side omni’s help you. Your driving on a slippery hall floor, can you drive it as well on the floor mats? I’m thinking that the added friction would reduce some mobility.
I think the purpose of this drive is to give more power to an X-drive (which have less torque than tanks) without having the inefficient use of 1-2 motors on an H-drive or using 8 motors on the X-drive. The 2 omnis on the side are for extra drive power. The biggest problem I see is turning, which, to be fair, is a pretty big problem.
Yes the turning part is what I was thinking about, thanks @ET phone home for putting it into words. Forward -> Better Side strafe-> about the same Turning -> I see lots of scrubbing even with the rollers.
It’s also some tricky programming to get the best efficiency of the side motor. Maybe someone with more time (Hey @tabor473 !) can produce code that would be the combination X and + drive. I’m not suggesting a 8 motor base, but it would lay the foundation for the 6,7 and 8 base. I don’t think the 8 motor base in that config has a name, so I’m going to claim naming rights. I’m leaning towards OctoOmni. Or maybe the Franklin drive since the wheels alone would be $100.
For an 8 motor X-drive you could just use 2 motors on each wheal. You don’t need 8 wheals.