5278C CI7D Reveal

great CAD! I wonder if x drives will be meta…


Thank you! We decided on an X drive because of the versatility it provides. With very few balls on the field, we want to be able to quickly maneuver to get them.

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I hope so. That is what we are thinking of building…

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Same, I’m also looking to run an X Drive, because you can move in any direction and you also get extra speed without needing gear ratios

Building it is my only issue right now. I hate cad and cad seems to hate me back

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There is this alternative to traditional CADding that is coming out soon. Maybe you can sign up for the beta and give it a go?

I asked him but he says it is not official yet but when it is I shall be the first to use it. [insert evil laugh here]:wink:


I never experimented much with X drives, how are X drives faster than normal tank drives? and is it by a lot?

They are sqrt(2) ~= 1.41 times faster and have 1.41 times less pushing force, compared to the regular drive.

Total power of the motors do not change, but you get different effective gearing ratio by having wheels at 45 deg angle.


Could you explain to me how you calculated this?

I’d also like to know the calculation

I don’t fully understand why it’s faster, but I found this website: https://aura.org.nz/why-is-x-drive-faster/

The sqrt(2) comes from the 45 degree angle of the wheels, so the force vector is angled at 45 degrees, and then if you do some right triangle calculations, it’s just a 45 45 90 triangle.



I think X drives could be viable, but the biggest tradeoff is the lack of any pushing power. The wheels angle won’t allow the robot to do well in pushing matches, I guess we’ll see which becomes more important

With x drive, I’m planning to use my maneuverability and speed.
My strategy is to gain speed and then ram the opponents side, using my momentum to slam them around the field.

Is that level of offense legal? Also if you did that there is a likelihood that you’ll damage your own robot…

maybe if it is a collision where both robots are going full speed and hit the most vulnerable part of the robot

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What exactly is an indexer?

An indexer is an auxiliary roller that is used to “index” game objects. It will keep them in a set position and can also feed them to other mechanisms (like a flywheel). In this case, it is being used to feed the balls to a mini-flywheel (it gives it enough time to speed up).


Our team considers it like a sorting stick basically that can sort out balls depending on color and it can also prevent the balls from reaching the flywheel, however, we don’t know if we’ll do that often. The flywheel is 840 rpm, capable of 4200, so it doesn’t need to spin up that much.

I think in coding, it’s something to like quickly sort/manage data, and in this case, the balls and their color are the data.

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