I am going to present my design and fabrication process for the Wallaby conrod in three posts: one focused on the Computer Aided Design (CAD), one focused on the Computer Aided Machining (CAM), and one on the actual machining.
Above is the drawing for the Conrod with most of the critical dimensions, there are some minor dimensions such as fillets and radii that are not called out. These could be shown on another sheet and are defined by the choice of the end mill used.
Here are a couple views of the 3D model for the connecting rod.
The next series of pictures detail the steps I went through to create the 3D model. The dimensions for each were pulled from an initial sketch. The final drawing is a result of the final CAD model.
I first used a “revolve” feature to create the two barrels for the piston pin and the crankshaft main journal.
I added the web between the barrel sections, this will eventually be shaped as an “I” beam for max strength and min weight. The lightning cutout will be added later. This is a simple “extrusion” feature.
The “extrusion” feature on the end cap for the end cap screws to bear down on.
Above is another “extrusion” feature for the threaded end cap screws. Fillets have been added around the big end barrel. I used a “fillet” feature, but due to the complexity of the multiple surfaces that intersect, a blended surface would look better. I may go back and improve this area.
Below a “cut” cut feature gives us the side profile we need.
Below are three “cut” features: the counter sink for the head of the cap screw, the clearance hole for the cap screw and the threaded portion in the conrod.
Then finally the lighting cutout “cut” feature in the web.
Next I am thinking that I will show the steps to machine and insert the associated CAM process where it is needed.
Let me know if this is interesting, too much detail or not enough. thanks.