It was so cold overnight that even with a block heater plugged in my diesel truck would simply not start this morning. So, I won’t be going into the shop today, or anywhere else for that matter, and have therefore some time to do another installment in this series. Previous posts are archived to the right of the page. This is the penultimate post, and is no more difficult than the preceding two posts in terms of what will be done today.
Where I last left off, I have completed the drawing of the lines for the front and rear planes of stick ‘a’ upon the unfolded view of stick ‘b’:
Now in post 8, I developed one of the faces on stick ‘a’, a face which I colored blue. In the same post I developed the remaining face of stick ‘a’, and colored it yellow. Today I will likewise develop both of those faces, as the technique is identical for both and in fact the process is much that same as was detailed for the other two faces already developed. Here then are the two planes to be dealt with today:
Then, as the reader may recall, points 9, 10, and 11 projected 90˚ across to meet the ground line of stick ‘b”s elevation view, giving points 9′, 10′, and 11’. These points in turn were projected across the elevation view to give points 9″, 10″ and 11″. In the next drawing I connect points 9″, 10″, and 11″ to form a picture of the cutting plane, in red to the left, on the elevation view of sitck ‘b’:
Next, we connect the dots as before, remembering that the arris on each side of the unfolded view is one and the same:
That zig-zagging line then is the red plane from stick ‘a’ as it crosses the various faces of stick ‘b’. If I clean up the view a little, you can see the three plane lines now formed on the unfolded view of stick ‘b'”
That completes the projection lines of all 4 planes from stick ‘a’ onto stick ‘b’. The final step, and subject of the next post in this series, is to mark out the material to be cut away from stick ‘b’ so that it can be fitted to stick ‘a’. That step is probably the hardest of all the steps in this problem, and requires careful consideration and visualization. See you next time.