hi mickey2times,
i suspect the KE is giving your simulation a problem in displaying a constant value throughout the motion

y = -ve, KE = ok
y = -some value below zero, KE[sub]0-[/sub] = ok
y = some value above zero, KE[sub]0+[/sub] = a bit different from KE[sub]0-[/sub]

i could not solve this problem but i suspect it could be overcome by setting up an event handler to calculate the KE at y = 0, assign the KE[sub]0[/sub] into the release KE at some t in between the t KE[sub]0-[/sub] and t KE[sub]0+[/sub]

attached is my attempt to implement Prof Hwang custom method myYvalue(y) which works!