thanks :)

I got this

radial.axis        = -v.vector(5*cos(phi)*s[1]**2, 5*sin(phi)*s[1]**2)      # -m*r*omega^2
transverse.axis =  v.vector(5*sin(phi)*alpha, -5*cos(phi)*alpha)/(2.1*g)  # m*R*alpha

I'm not sure this is correct though, what's happened to m*g being subtracted?
Is that needed?


I know where i was going wrong with the angles now, I forgot that they're measured from the line x=0 to the pendulum bob's position :P