Question: several parametric plots into one figure

Hello,

I have two functions :
x(apha1,alpha2)
y(alpha1,alpha2)

When alpha2 is fixed, i can make a parametric plot to see the evolution of the point M which have the coordinates (x,y).

Consequently, 

for alpha2 = 30°, i can plot 

plot([eval(X(alpha1,30*Pi/180)),eval(Y(alpha1,30*Pi/180)),alpha1=-30*Pi/180..30*Pi/180],-1..1,-1..1);

for alpha2 = 25°, i can plot 

plot([eval(X(alpha1,25*Pi/180)),eval(Y(alpha1,25*Pi/180)),alpha1=-30*Pi/180..30*Pi/180],-1..1,-1..1);

for alpha2 = 20°, i can plot 

plot([eval(X(alpha1,20*Pi/180)),eval(Y(alpha1,20*Pi/180)),alpha1=-30*Pi/180..30*Pi/180],-1..1,-1..1);

and so on ...

I would like to plot these different parametric plots with a increment of 5 degrees for alpha2 from 30° to -30°. But, i would like to gather all the plots on the same plot.

I attach my code. My attempt with a for loop doesn't work.

How can i do such a plot (gathering several parametric plots) ?

Thank you for your help.

Analyse_cinematique_vehicule_4D_28.01_test.mw