# What's the fastest possible drivetrain in vex?

I just wondering what the fastest drive base possible within the VRC regulations is.

Anything 8 motor and 600 RPM geared UP
So like 4200
8400
16800
33600
etc

and using the 4 inch wheel?

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VRC does not have a â€śspeed limitâ€ť.
It does have a saftey rule, so if you plan on making your robot go >1000 in/sec and forget to add spoiler on the back, you may fly out of the arena and hit a bystanding llama which will get you DQâ€™d.

However, physically possible, how about you try and post it?

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While this advice is theoretically good, It is completley nonsensical for the average person. The speeds you were talking about, especially the latter speeds, have insane torque dropoffs and speed, which means needing to be super small, light, and an incredible drivetrain. Almost nobody in all of VEX history has ever run a successfull robot faster than 84 IPS.

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im guessing becasue of the 3600 rpm motor you can get around 25k rpm out of it. the formula for it is â€”multiply half the diameter by 2 times pi, then multiply again by the RPM over 60. I do not have a calculator on me now
assuming you are using 4in wheels
2PIx.05)x(25000/60
you get around 133 feet per second which turns into roughly 90mph. The robot will likely never get to top speed however because it is geared down so low.
This was not meant to be super accurate, I could make it super accurate but that would take me away from finishing my physics homework

Using a simple insert you can actually get 3600 rpm from each motor also. This being without gearing

Fully agree with this statement, with the slight change that I have performed with a 6 motor drivetrain direct driving on blue gearboxes, which I believe gives a hypothetical 102 inches per second with little to no noticeable drop-off in acceleration. However, once it was engaged in a pushing battle or experienced overheating, the lack of torque made it far from ideal. And even still, if you can master driving at 102 inches per second then good for you, but the lack of torque and control means you should take another look at balancing speed with other properties necessary for success.

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Also one thing to think about is the weight impacting the torque over the motors. For example, if you are driving a 1000 tooth gear (not real) to a 1 tooth gear with the wheel (also not real) then it might not be able to even move the vehicle since the amount of torque is so low. And so even though theoretically it is fast, I reality it would be very slow.

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More like a 1000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 tooth gear to a 1 tooth gear, if that were a thing and if it was used on a flywheel, we would have triballs launching all the way to our farthest neighboring galaxy

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You just broke mechanics.

The fastest drivetrain Iâ€™ve seen is 600 on 3.25 if I am correct. I forget the team number but it was in a FUN video.

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Iâ€™ve seen 600 RPM on a 2.75" wheel (~86 IPS), but I donâ€™t remember a 3.25".

There are also 400 RMP on a 4" wheel which is about the same speed (~84 IPS).

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One of my friends is running 600 3.25

Really they had a 600RPM motor, AND was feat in FUN?

I would love to see 600 RPM direct drive on the vex pros 8 inch Omni wheels. Obviously not competition legal for VRC, but I think it would be funny.

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Thinks far too much
Wouldnâ€™t that beâ€¦a tiny flat wheel? Or a wheel with a bump?

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Actually, 1032Z and 4082B ran 600 on 3.25 (102 ish ips) at the state championship and they did way better than us and we are running 450 2.75

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The fastest possible drivetrain (which I want to build) would be 8 3600 RPM cartridges with a 1:7 ratio.

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Maybe get a hundred motors and make them staked try that

no but it has to be within the vex competition. THat is one of the restrictions.

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