Chopper skins were derived from drawings provided by Paul Murphy (Joymonkey) who converted his .pdf drawing to a Autocad .dwg drawing for me. I've posted links here to both the full size .pdf drawings as well as the .dwg files that they were derived from. The .pdf files come both with and without dimensions. If you don't already have a CAD package that can work with .dwg files Dassult Systems provides a free version of their Draftsight package.
made a number of changes to Paul's files:
I scaled them up to correct size (his originals were about 1/6 full size), corrected panel lines that were not vertical or horizontal (most likely caused by 1 pixel differences during scaling) removed all but one of the panel lines (there were sometimes 2 or 3 lines on top of each other, Paul compared drawings from multiple sources to create his drawing) and I adjusted the top strip to be precisely 1 in and total skin height of 14 in to cover a body diameter of 18.875 in. For my convenience, I created several layers in the .dwg file (skin, features, dim, dim-panels, etc.) so that sections of the drawing that were not being worked on could be turned off. For these drawings I distinguish between "panel lines" and "skin features" (things like holes & slots cut into the skins). The major dimensional change was moving the shoulder mounting holes to 4.25 in down from top edge and changing shoulder mounting holes to 3.25 in diameter (both to match Cleofett's drawings). To make them compatible with CNC machining, the lines, circles and arc's that were in the drawing as splines (many small straight lines that approximate a circle) were converted to true lines, circles and arcs. That also required making guesses at what the dimensions for the features really were. Using a table of fractional to decimal conversions I chose the closest decimal equivalent (in essence, converted to the nearest 1/64 in fractional measurements). Finally, I added slots ( double lines 1/16" (.0625) wide ) to replace panel lines [both are available on the drawing file]. I've also created 3D models of the skins using the sheet metal (preview) features of F360. Links to the F360 models are included below. Because of their small size the panel lines do not show up well unless you zoom in on the 3D model. Given the size of the skins (14x29.65) the .pdf drawings are ANSI D size (34x22) so that, if you want, you can print full sized skin layouts.
link to .dwg, link to .pdf, link to .pdf with dimensions, link to F360 3D model. This design is copyright Media-Conversions LLC and is made available for non-commercial use only.
link to .dwg,
link to .pdf, link to .pdf with dimensions, link to F360 3D model. This design is copyright Media-Conversions LLC and is made available for non-commercial use only.
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