// Shelf Bracket
// 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.

// Define constants
sigmaAllow = 35000 // psi (6061-T6 aluminum)
width = 6 // inch
p = 300 // Force on shelf - lbs
factorOfSafety = 1.2 // FOS of 1.2
shelfMountL = 5 // inches
wallMountL = 2 // inches
shelfDepth = 12 // Shelf is 12 inches in depth from the wall
moment = shelfDepth * p // assume the force is applied at the end of the shelf to be conservative (lb-in)


// Calculate required thickness of bracket
thickness = sqrt(moment * factorOfSafety * 6 / (sigmaAllow * width)) // this is the calculation of two brackets holding up the shelf (inches)


filletRadius = .25
extFilletRadius = filletRadius + thickness
mountingHoleDiameter = 0.5

sketch001 = startSketchOn(XZ)
  |> startProfileAt([0, 0], %)
  |> xLine(length = shelfMountL - thickness, tag = $seg01)
  |> yLine(length = thickness, tag = $seg02)
  |> xLine(length = -shelfMountL, tag = $seg03)
  |> yLine(length = -wallMountL, tag = $seg04)
  |> xLine(length = thickness, tag = $seg05)
  |> line(endAbsolute = [profileStartX(%), profileStartY(%)], tag = $seg06)
  |> close()
  |> extrude(%, length = width)
  |> fillet(radius = extFilletRadius, tags = [getNextAdjacentEdge(seg03)])
  |> fillet(radius = filletRadius, tags = [getNextAdjacentEdge(seg06)])
  |> fillet(radius = filletRadius, tags = [seg02, getOppositeEdge(seg02)])
  |> fillet(radius = filletRadius, tags = [seg05, getOppositeEdge(seg05)])

sketch002 = startSketchOn(sketch001, seg03)
  |> circle(center = [-1.25, 1], radius = mountingHoleDiameter / 2)
  |> patternLinear2d(instances = 2, distance = 2.5, axis = [-1, 0])
  |> patternLinear2d(instances = 2, distance = 4, axis = [0, 1])
  |> extrude(%, length = -thickness - .01)

sketch003 = startSketchOn(sketch001, seg04)
  |> circle(center = [1, -1], radius = mountingHoleDiameter / 2)
  |> patternLinear2d(instances = 2, distance = 4, axis = [1, 0])
  |> extrude(%, length = -thickness - 0.1)