/**
I lost a lens cap for my binoculars many years ago.
With a 3d printer and TPU filament, I can make a replacement that fits perfectly.
I printed 2, because when I tested the fit, the *original* lens cap fell off.
No wonder I lost the original - they are too big!

NOTE
    My eyepieces are very nearly 40mm diameter, so a 40.3 mm internal diameter,
    and a 0.6 inset means that the final internal diameter is SMALLER than the binoculars.
    So it will need to stretch to fit on, and therefore be a snug fit, which will not fall off.
    However, my final parts are SMALLER than intended, but still fit fine.
    If your printer/slicer is setup "correctly" to account for shrinkage of the final piece,
    maybe you will need to reduce the size to make it as snug as my prints.

*/
class LensCap : Model {
    
    @Custom(about="Internal diameter and depth")
    var size = Vector2( 40.3, 8 )

    @Custom(about="Thickness of the edges (not the base)")
    var thickness = 1.2

    @Custom(about="Thickness of the base - the part that touches the build plate")
    var baseThickness = 2.4

    @Custom( about="Thickner in the middle buy a little bit to help the cap stay on" )
    var inset = 0.6

    @Custom
    var chamfer= 0.8
    
    override fun build() : Shape3d {
        return ExtrusionBuilder().apply {

            crossSection( Circle( size.x / 2 + thickness -chamfer ) )
            forward( chamfer )
            crossSection( chamfer )
            forward( size.y + baseThickness - chamfer )
            crossSection()
            crossSection( -thickness )
            forward( - size.y  /2 )
            crossSection(-inset)
            forward( ( - size.y + chamfer ) /2 )
            crossSection(+inset)
            forward( -chamfer )
            crossSection( -chamfer )

        }.build()

    }
}