thumb_xbot = 90;
thumb_dia = 25;
+vol_xbot = 87.4;
+vol_xtop = 106.7;
+vol_depth = 1.0;
+vol_zsz = 9;
+vol_zoff = 0;
+
rail_ysz = 2.5;
rail_zsz = 2.5;
$fn= 20);
}
+ mirror([1,0,0])
+ translate([ (vol_xbot+vol_xtop)/2, 0, psz[2]/2 + vol_zoff ])
+ cube([ vol_xtop-vol_xbot, vol_depth*2, vol_zsz ], center=true);
+
translate([ thick[0], -10, -10 ])
cube([ 10, psz[1]+20, psz[2]+20 ]);