add angle brackets style

angle_bracket.scad

@@ -0,0 +1,54 @@
+$fn=33;
+
+height=40;
+width=60;
+b=3;
+triagleheight=5;
+M3HoleDiam=3.4;
+
+holedistance=10;
+
+
+difference() {
+    frame();
+    holes();
+}
+
+module frame() {
+    // x plate
+cube([width,b,height]);
+
+// y plate
+translate([b, 0,0]) rotate([0,0,90]) cube([width,b,height]);
+
+//bottom triangle
+translate([b,b,0]) stabilizetriangle();
+// upper triangle
+translate([b,b,height-triagleheight]) stabilizetriangle();
+}
+
+module holes() {
+    // y holes
+    translate([0,holedistance,height-holedistance]) YM3Hole();
+    translate([0,width-holedistance,height-holedistance]) YM3Hole();
+    translate([0,holedistance,holedistance]) YM3Hole();
+    translate([0,width-holedistance,holedistance]) YM3Hole();
+    
+    
+    translate([holedistance,0,height-holedistance]) XM3Hole();
+    translate([width-holedistance,0,height-holedistance]) XM3Hole();
+    translate([holedistance,0,holedistance]) XM3Hole();
+    translate([width-holedistance,0,holedistance]) XM3Hole();
+}
+
+module stabilizetriangle() {
+    linear_extrude(triagleheight) polygon([[0,0], [0, width-b], [width-b, 0]]);
+}
+
+module YM3Hole() {
+    rotate([0,90,0])cylinder(h=b, d=M3HoleDiam);
+}
+
+module XM3Hole() {
+    rotate([270,0,0])cylinder(h=b, d=M3HoleDiam);
+}