Week 9 - Attachment Feature Creation - Challenge 1

AIM: Design of ribs for the coin holder component

(Image taken from the skill lync design classes)

I will design from the bottom of the coin holder.

Wall thickness is denoted as t for calculation.

• First I will create the sketch for the required rib.
• 

• I will create a single rib and then do others if the rib is satisfied for every calculation.

The formula for the Rib height should be smaller than or = wall thickness (t) x 5

= 2.5 x 5

= 12.5mm

• Then the thickness of the calculated as

Rib thickness (w)= 0.4 x wall thickness (t)

= 0.4 x 2.5

(w)= 1mm

Then the Draft angle for the rape is calculated as

Rib draft should be greater than and equal to 0.5 degrees

rib thickness at the tip after draft should be greater than or = 0.75mm

then at last the rib Fillet is calculated

Rib fillet radius (r) = 0.125 x wall thickness (t)

= 0.125 x 2.5

= 0.3125 mm

After fully designing the rib, let me find the Rib Root Thickness Value for the rib and Body.

Here we can see the wall thickness is 2.5 and Rib root thickness is 2.71 which is greater than wall thickness. So at the junction of rib and wall thickness, it may create a little amount of sink mark

The spacing between the rib is calculated by 2 x wall thickness (t)

rib spacing = 2 x 2.5

= 5 mm

and the ratio between the height and the spacing is classified into two parts

For steel, it is 3:1 ( less than 3

and for other or preferred is 2:1 ( less than 2)

Therefore,

rib height / rib spacing = less than 2

12.5 / 5 = 2.5

not less than 2

so increasing the Rib spacing distance to 1 mm or more

12.5/ 6.5 = 1.92 (which is less than 2)