Unexpected behaviour with 0 horizontal velocity

[jake-goldsmith]

Hi,

I've been playing around with some different initial conditions and am a bit confused why when throwing the frisbee vertically upwards with no spin it doesn't fall directly downwards.

Initial conditions:
Disc(vx = 0.00001, vz = 20, dgamma=0))

Output:

I also tried to plot the velocities.

It looks like rather than going straight up and back down again the frisbee has tilted to the right and sped up in that direction which confuses me as I can't understand why the disc would tilt that way. I also don't understand why vz appears to not go below 0 despite the disc appearing to fall in the visualisation.

Do you have any idea what might be causing this? Could it be an error in the underlying model, or is it some sort of artifact from the simulation?

Any help would be appreciated, thanks!