48 lines
2.2 KiB
Plaintext
48 lines
2.2 KiB
Plaintext
// Shelf Bracket
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// This is a bracket that holds a shelf. It is made of aluminum and is designed to hold a force of 300 lbs. The bracket is 6 inches wide and the force is applied at the end of the shelf, 12 inches from the wall. The bracket has a factor of safety of 1.2. The legs of the bracket are 5 inches and 2 inches long. The thickness of the bracket is calculated from the constraints provided.
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// Define constants
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sigmaAllow = 35000 // psi (6061-T6 aluminum)
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width = 6 // inch
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p = 300 // Force on shelf - lbs
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factorOfSafety = 1.2 // FOS of 1.2
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shelfMountL = 5 // inches
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wallMountL = 2 // inches
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shelfDepth = 12 // Shelf is 12 inches in depth from the wall
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moment = shelfDepth * p // assume the force is applied at the end of the shelf to be conservative (lb-in)
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// Calculate required thickness of bracket
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thickness = sqrt(moment * factorOfSafety * 6 / (sigmaAllow * width)) // this is the calculation of two brackets holding up the shelf (inches)
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filletRadius = .25
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extFilletRadius = filletRadius + thickness
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mountingHoleDiameter = 0.5
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sketch001 = startSketchOn(XZ)
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|> startProfileAt([0, 0], %)
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|> xLine(length = shelfMountL - thickness, tag = $seg01)
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|> yLine(length = thickness, tag = $seg02)
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|> xLine(length = -shelfMountL, tag = $seg03)
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|> yLine(length = -wallMountL, tag = $seg04)
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|> xLine(length = thickness, tag = $seg05)
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|> line(endAbsolute = [profileStartX(%), profileStartY(%)], tag = $seg06)
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|> close()
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|> extrude(%, length = width)
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|> fillet(radius = extFilletRadius, tags = [getNextAdjacentEdge(seg03)])
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|> fillet(radius = filletRadius, tags = [getNextAdjacentEdge(seg06)])
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|> fillet(radius = filletRadius, tags = [seg02, getOppositeEdge(seg02)])
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|> fillet(radius = filletRadius, tags = [seg05, getOppositeEdge(seg05)])
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sketch002 = startSketchOn(sketch001, seg03)
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|> circle(center = [-1.25, 1], radius = mountingHoleDiameter / 2)
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|> patternLinear2d(instances = 2, distance = 2.5, axis = [-1, 0])
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|> patternLinear2d(instances = 2, distance = 4, axis = [0, 1])
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|> extrude(%, length = -thickness - .01)
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sketch003 = startSketchOn(sketch001, seg04)
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|> circle(center = [1, -1], radius = mountingHoleDiameter / 2)
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|> patternLinear2d(instances = 2, distance = 4, axis = [1, 0])
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|> extrude(%, length = -thickness - 0.1)
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