If you have a mold with one sprue, three runners and six gates and you want a gating ratio of 1:4:6 and the bottom of the sprue is 1 in2, what is the width of each runner and gate

Width of runner = 2.667 in

Width of gate = 2 m

Explanation:

1 sprue

6 gates

3 runners

Gating ratio = 1:4:6

Bottom of sprue AS = 1 in 2

Width (b) of runner =?

Width (B) of gate =?

Height (H) of runner and gate = 0.5 in

All gates and runners and gate = 0.5 in

All gates and runners are equal  

Now,

Gating ratio = AS : Ar : Ag

Where,

As= sprue area  

Ar = runner area  

Ag = gating area  

1:4:6 = AS : Ar : Ag

Ar = 4As = 4 x 1= 4 in 2

Ag = 6 Ab = 6 x 1 = 6 in 2

Now,

Area of single runner is,

Ar/3= b x h

4/3 = b x 0.5

b = 2.667 in

Also, area of gate  

Ag = 8 x h

6/6 = B x 0.5

B= 2 m