Making the Sprocket

Creating the sprocket

I drew a rectangle with the shape option and lined the side of the rectangle up with the left side of the sprocket. After converting the rectangle to an editable spline I reshaped the rectangle to line up the match the width of the sprocket. I applied the lathe modifier and then used align to max to eliminate some inner penetration. To create the hole in the middle I aligned the axis of the lathe to fit the shape of the sprocket. I then aligned the sprocket to the frame.

I selected the top polygons after converting the object to an editable poly and used the scale tool to scale the polygons in and then applied NURMS. I used the swift loop to add resolution to the edges of the sprocket.

Made a tube that started inside the sprocket and ended just outside of the sprocket. I then centered the tubes pivot to the object and then aligned the center of the tube to the sprocket. I then used the swift loop to add some geometry to the inside of the tube. Next I selected two of the top inside polygons and extruded them. I reshaped the top edges of the the extrusions so that the middle went up and the side edges sloped downwards. I selected the four side polygons including the extrusions and created an inset and then extruded that inset inward into the tube. I applied NURMS and then used the swift loop to insert some geometry into the tube.

I selected the inside edge polygons and deleted so the sprocket pieces could later weld. I then copied the sprocket by holding shift and rotating along the Z-axis 180 degrees. I then rotated the copied piece again 180 degrees along the Y-axis and moved the sprocket copy to the other side.

I attached the two seperate pieces so I could select vertices on both objects, I then selected the top inside borders and converted them to vertices and then welded the two pieces to bridge the gap. I repeated the same process on the bottom inside borders. to remove the piece of the frame that penetrated to the sprocket I changed the curves of the bottom frame piece so that they were inside the sprocket but not going through.