Any reason aluminium extrusion isnt part of the parts library?

[twitchyliquid64]

As the title says, I was pretty surprised there was no generic 2020 extrusion in the parts files.

I made one for generic 2020 as a side project to my first project with BOSL2, feel free to use (or feedback if its 💩 ):

include <BOSL2/std.scad>
include <BOSL2/screws.scad>

module ext_2020(
    l=60, s=20, edge_r=1.5, bore_r=2.5,
    slot_inset = 1.5, slot_inner_width = 11, slot_outer_width = 6.2, slot_depth = 4.3,
    cut_width = 5.26,
    anchor=BOTTOM, spin=0, orient=UP,
) {    
    tag_scope() diff()
        cuboid([s, s, l], rounding=edge_r, edges="Z", $fn=20, anchor=anchor,spin=spin,orient=orient) {
            align(CENTER, inside=true) cylinder(r=bore_r, h=l+1, anchor=CENTER);
            
            // trapezoidal slots
            face_mask([LEFT, RIGHT, FRONT, BACK])
                down(slot_inset)
                prismoid([slot_outer_width, l+1],[slot_inner_width, l+1],height=slot_depth, anchor=TOP);

            // cuts
            face_mask([LEFT, RIGHT, FRONT, BACK])
                up(0.01)
                cube([cut_width, l+1, slot_inset+0.02], anchor=TOP);

            children();
        }
}

ext_2020()
    position(RIGHT) orient(RIGHT)
        screw("M3", head="socket", drive="hex", length=12);

[revarbat]

I designed and printed some 80-20 before, but it came out terribly. There is no orientation that it can be printed in (with FDM/FFF) that doesn't break along layer lines when you tighten a screw down on it. So I never added the part to the library.

However, I can see the use of having it in the library, for image generation, or for printing in metal.

[revarbat]

I'd suggest making a 2D 80-20 profile module that can be linear_extrude()ed, for most flexibility and speed.

[revarbat]

Thinking on it, the various sizes of 80-20 may have profiles that aren't just scaled versions of one another.

[twitchyliquid64]

I'm actually using my 2020 module to help me visualize the assembly, but yeah definitely not going to print it 😅 but I will buy some and feed it to the chop saw :P

[twitchyliquid64]

Agree that finding a way to make it parametric so you can do 2040, 8020 etc sounds ideal.