The first three pictures are without the details to better understand the construction,The blue pencil shows the mistakes I made:
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Here show the red pencil my mistakes:
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After two tests I should draw the details,....
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....but I thought it's better to trace the construction and draw the details on seperate paper, that it's easy to see how I use the constructions.
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After I finished these drawings Jose took a look to see each mistake I made, just like in this finished drawing: me - red
Jose- blue.