Week 9 - Attachment Feature Creation (Ribs & Screw Boss) - Challenge 1
Challenge is to create Ribs for the given part with considering the guidlines of rib creation.
Creation of tooling axis.
For creation of tooling axis first a point on the flat horizantal surface is created and axis system on the point is also created. Then a interesection of the plane and class A surface at the point is created. In the interesection line obtained the two side wall line (1 &2 in picture) is used for creating a bisecting line between the two lines. This bisecting line is tooling axis as shown in the picture above.
Draft analysis of the part with 3deg to the tooling axis.
0 to 3deg is full green 0 and negative angle is blue. Here we observe the side walls of the part is blue which is a problem. This is because the A surface is used as this has the vertical surface as received. This is obeserved on both sides and so the axis cannot be adjusted. With 0.5deg as draft analysis the below result is seen. The red areas have turned green and even here the side walls are blue.
The final part sides are trimmed to 0.5deg and the result of draft analysis at 0.4degree is as below. Since the Class A cannot be altered this is only a remedy to the molding problem which can be communicated to the surface creation department.
Picture of the final part below.
Below is the sketch obtained by intersection of plane and part and the measurement shows the dimensions maintained.
Thick ness is 2.3mm
minimum rib thickness is 0.4t which is 0.4 of 2.5=1mm
Rib height =>5t which is 2.5x5=12.5
Rib root thickness diameter specified limit is 30%+thickness which is 2.5+0.75=3.25
Screw boss details below
Screw hole is for M4 thread and hole diameter is 3.2.
Outside diameter can be 2 to 2.4 of hole diameter so hole is 3.2mm and OD can be 3.2*2=6.4
Boss height 3:1 three times thickeness and so 2.5x3=7.5mm
