One way to build a wood crate buck

[RockHillWill]

I just completed the drawings for this Model A fender buck, and am posting while it is all fresh in my mind. This is not the only way, just one way. I like making drawings, so this is the approach that I have taken, and from my limited experience, I like the fact that I can use it as a hammer form buck if I need to. In some previous bucks, I was too liberal in making the buck ribs be vertical, leaving too much sanding to fit the actual contours. That also made it harder to hold up under some of the 'angled' hammer blows. I learned the West System glue usage from Jim Hery and the 3D scanning was done by Scott White at the last Redneck Roundup.

This the .IGES file that was sent to me by Scott White after he 'worked over' the point cloud from the 3D scan taken in the shop.
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I saved that file as a parts file in SolidWorks.
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One of the earliest steps was to establish a base and back bone that could be cut out of the available 60" x 60" Baltic birch plywood. Then a 'plane' surface was determined at the highest point of the contour and using the cut surface of the 3D scan the back bone was drawn to match that contour, and the cross web locations were cut in place.
MA3.jpg

By establishing a working plane at one side of the web slots, and using the edge of the fender as determined by the cutting plane, a cross web contour was established then extruded to the thickness of the plywood. By using the 'convert entities / intersection curve' command the dark line along the contour is established at the exact location of the fender skin.
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This is the combination support and contour web from the above cross section.
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Pre-assembly holes were added to the SolidWorks drawing of the base to locate the support webs and the component assembly was started.
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One of the last cross ribs about to be inserted on to the back bone.
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Pre- assembly of the drawing components almost completed.
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Components in place. The notches at the side are for the edge ribbing. Where the edging looks to be protruding shows where the edging will be bent to the fender contour at the assembly gluing process.
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Individual drawings are then made and further saved as a .dxf file for use at the water jet place. Minimal dimensions are required only to allow the water jet operator to check the scale before cutting.
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For these larger projects, I assemble the components into a 60" x 60" plywood panel for cutting at the same time.
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This is the drawing, in .dxf format that will be sent to the water jet guy for cutting. In both the above and below photos there are components that are for a Bugatti headlight buck project, as I could take advantage of combining projects.
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Here is a picture of the completed buck without the fender in place.
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This picture shows the fender superimposed on the buck. The parts that show above the fender scan are the areas that will need to be 'custom' sanded before being able to use the buck. The red outer edging component is made longer than the fender to account for the material needed to include the wire edging prior to forming the fender edge bead typical of the Model A's.
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