+ cylinder(r=arm_pin_dia/2, h=100, $fn=20);
+ }
+ difference(){
+ translate([-armpart_main_width/2, 0, 0])
+ cube([armpart_main_width, armpart_main_thick, armpart_main_height]);
+ translate([0,50,armpart_hinge_height])
+ rotate([90,0,0])
+ cylinder(r=hingepin_dia/2, h=100, $fn=20);