How To Create Triangular Patterns

While there are many examples of triangular patterns, this one is intended to create a pattern that can be dynamically modified using a parameter. The number of holes in the base of the triangle is modified using parameter Base. The pattern updates to create a triangle with the number of holes in the bottom row equal to the value of parameter Base. Just follow these steps.

1. Create a 100 x 50 plate, and create a hole at the lower left corner at 10 units from the vertical and horizontal edges (Fig. 1).

Figure 1.

2. Create the following parameters:

3. Choose Feature, Pattern. Pick the hole for creating the pattern.

4. Select type as General, Done.

5. For the Dimension increment, select Relation and pick dimension d4 (Fig. 2) as increment dimension in the first direction. Pick Edit, and enter following relations in the text editor:

hole_number=idx1+1

cur_row=1 solve

hole_number=((2*base+1)*cur_row-(cur_row)^2)/2

for cur_row

cur_row= ceil(cur_row)

memb_v=lead_v+((spacing/2)*(cur_row-1))+\
(hole_number-(((cur_row*((2*base)-cur_ row+3))-\
(2*base))/2))*spacing

Select Done.

Figure 2.

6. Select dimension d5 as another dimension in the first direction. Pick Edit and enter following relations in the text editor:

hole_number=idx1+1

cur_row=1

solve

hole_number=((2*base+1)*cur_row-\
(cur_row)^2)/2

for cur_row

cur_row= ceil(cur_row)

cur_row=floor(cur_row)

memb_v=lead_v+(spacing/2)*tan(60)*(cur_row-1)

Select Done.

7. Enter 21 as the number of instances in the first direction.

8. Select Done for the second direction. The triangular pattern is ready (Fig. 3).

Figure 3.

9. The final step is to relate the parameter Base with the pattern number. Enter the following relation into the part relations:

Pattern (P#)= (base*(base+1))/2

Figure 4.

10. Now change the parameter Base to 5, and select Regenerate. The pattern should regenerate as shown (Fig. 4).

Sanjay Kinger can be reached by e-mail at sanjay_kinger@yahoo.com.