That is a good argument. i suppose i am biased this year because in the case of flywheels. The flywheels are easy to use y cables for. Pneumatics can be extremely useful but i believe that 2 extra motors are easier to work with. just my two cents
Of course two motors is easier to work with! And that can be very useful. I think that 12 motors was a good way to get thinking about power allocation and motor consolidation and my club’s new teams will definitely by taking advantage of this.
Defintely needs to be considered. especially since pneumatics have been around forever but this is the first time 12 motors have been allowed
I still think 2114A’s drive would be better. It doesn’t use pneumatics, yet it still has an effective transmission. It has the glories of both tank and X-drives, with the cost of only 1 motor.
It uses the same amount of motors as an H-drive and I think that is game changing.
This kind of thinking isn’t really correct either. There is no difference between an X drive and a tank drive that has been geared up by a factor of 1:root2. Assuming any loss in energy due to friction of rollers, AN X DRIVE IS EXACTLY THE SAME AS A SIMPLE GEAR RATIO. At least for straight line driving it is.
For example, and X drive with 2.75" wheels will be close to identical to a tank drive with 4" wheels, if geared 1:1, 1:1.6, 1:2.4 or whatever else if you care to use gears. It should be similar speed and similar pushing ability (although I have heard 2.75" omni’s don’t behave as nicely as 4" omni’s)
An X drive is basically a tank drive that gains the ability to strafe for no cost of resources like pneumatics or motors, has a ‘virtual’ gearing of 1:1.414, but has the downsides of less straightforward construction, more space occupying wheels and increased difficulty in the use of things like transmissions, 6 motor linked drive-trains etc.
In which ways are 2.75" omnis less receptive? My team has not had any negative past experiences with them but we never competitively used them on a field. Are there any problems we should anticipate?
There is a small but noticeable amount of power lost to friction in the rollers when using an X drive, which makes it inherently less efficient then tank. If you’re just looking for efficiency then tank takes the cake. (It sometimes bugs me when people use the word “efficient” when they really mean “effective” or “good”.
The other two issues I see with X drives is that they usually turn slower, and moving diagonally will both be slower and have less torque, as only half the motors are used for the maneuver.
The X drive is a good design, probably the best holonomic in my opinion, but it does not come for free. A tank drive geared up to 1.41 times speed of an equivalent X drive will perform a little bit better driving straight (if the gearing is done well). You need to assess for yourself whether the strafe capability is worth this sacrifice for this particular game. I haven’t seen enough to have a strong opinion yet.
Note: From my experience, X drive performance declines greatly if a robot is heavy. With no tall lifts this year, robots are likely to be lighter and allow for more drive options.
Unrelated note: Using 12 motors on the cortex works great so long as you use a power expander. Certain teams got away without using one, but in my experience it’s necessary.
I agree with don on many of the aspects he mentioned. i just want to add that power expanders have difficulty with y cables at times so be cautious
to me, nothing but net represents a competition for opportunities - that is, getting to the objects before your opponents do, and grabbing the bonus balls especially. with that said, i think tank drives are the best choice with sufficient practice. as long as the driver can intuitively do quick maneuvers by Worlds, the extra speed and power gained from a tank is worth it IMO.
Where’s Kiwi drive? ;(
I agree with this 100%. You will have more pushing force and fairly high speed if you chose to use a tank drive, versus an x holonomic, or a h drive. (Or a Kiwi Drive for that matter.) SO basically, you will be able to get to your objectives faster, and with more efficiency than your opponents theoretically can if you build a well executed tank drive. Take a hint from last year, at the beginning of the year, 95% of the teams that I had on my “To Watch List” had holonomics, by the end of they year, most had opted for a more efficient tank style drive!
And how many tanks were on that thing at States? 
That robot was really nice, and I agree that pneumatics are more useful than the extra 2 motors, but in my opinion there are better uses for pneumatics than a crab drive for this game.
My team is going to use the X-drive this year, because we found that the balls move around very easily on the feild. The X-drive isn’t for every team it depends on your teams strategy what drive will be best to use. The X-drive happens to be the best drive for what my teams strategy is.
X drive also has great turning. probably the best because all of its wheels are angled in the perfect direction. I have had to slow down the motors when turning because sometimes the robot over spins.
I think that tank drives will be the most popular this year, and obviously there’s a reason for it. I mean, I assume most teams will decide to take the “robot-into-a-ramp” approach for lifting your partner, so X-Drives are essentially out. Octa and Asterisk Drives, I would assume, probably would run into the exact same problem. If I had to guess which drive would be the most practical, I would say probably H-Drives, but I’ve never actually used one before, so take that advice with a grain of salt. 