tube_or = tube_dia/2 + tube_th;
back_ohw = back_gap/2 + backflange_th;
-backflange_ymin = tube_or+backflange_d;
+backflange_ymin = tube_dia/2 + backflange_d;
lock_0y = tube_dia/2 + lock_d/2 + midweb_d;
lock_0x = lock_w/2 - lock_d/2;
for (z=[ 1/4, 3/4 ]) {
rotate([0,0, backflange_angle])
ThroughHole( r,
- -tube_or -0.5*backflange_d,
+ -tube_dia/2 -0.5*backflange_d,
total_h * z,
x);
}