I’m well aware that for a standard X drive with 45 degree angled wheels, the forward speed of the robot is theoretically 1.41 times faster than the speed of a tank drive with the same wheel size and rpm. But what about with an X drive that does not have its wheels angled at 45 degrees? I’ve been ex…

The multiplier will be secant(wheel offset) where 0 is straight forward wheels. Secant(90degrees) is undefined, which makes sense.

It doesn’t answer your question, but if you haven’t seen it, this was sort of fun. [image] Shifting X-Drive General Forum [image] Yet another transmission system, this one allows you to shift from normal 4-wheel tank drive to 45 degree x-drive wi…

yeah I’ve seen that. pretty cool, I’m attempting something similar except with a variable angle instead of just 0 or 45 degrees, and powered by a fifth motor instead of pneumatics.

[image] Xenon27: So basically my question is, how does one figure out the theoretical forward speed of an x drive just from a wheel angle? You break up the total velocity vector of each wheel into component parts and sum the parts. The direction and magnitudes of the resultant vector can be d…

@Kyle1 it is your time to shine

I would calculate it using force vectors.

[image] 2775Josh: The multiplier will be secant(wheel offset) where 0 is straight forward wheels. Secant(90degrees) is undefined, which makes sense. you sure about that? because secant(45) is 1.9, but we all know that 45 degree X drives have a speed multiplier of 1.41

[image] mvas: You break up the total velocity vector of each wheel into component parts and sum the parts. The direction and magnitudes of the resultant vector can be derived trigonometric functions (these will probably be for non-right triangles ) not entirely sure how to do that tbh. are t…

You’re on radians lmao. No worries, just type degrees after or switch your mode.

[image] 2775Josh: You’re on radians lmao. No worries, just type degrees after or switch your mode. ahh lol google calculator defaults to radians for some reason.

Here’s a graph showing how the multipliers for speed (red) and torque (blue) would change depending on wheel angle, with 0 degrees being parallel to the direction of motion. [Screen Shot 2021-01-12 at 11.35.50 AM] A cool demo with a robot like this would be to simulate a continuously variable tra…

Calculate Speed of a Non Standard X Drive

VEX V5 General Discussion Technical Discussion

jpearman January 12, 2021, 6:18am 2

It doesn’t answer your question, but if you haven’t seen it, this was sort of fun.