diff --git a/scad/positions.scad b/scad/positions.scad
index 491a1c9..5ed826d 100644
--- a/scad/positions.scad
+++ b/scad/positions.scad
@@ -60,10 +60,11 @@ z_nut_offset = frame_nut_traps ? -z_slot_inset + nut_radius(frame_nut) + 0.5 : 0
 function z_motor_bracket_hole_offset() = ceil(NEMA_width(Z_motor)) / 2 - z_slot_inset + z_nut_offset;
 
 left_stay_x = max(-base_width / 2 + left_w / 2,
-                  idler_end - z_bar_offset() + z_motor_bracket_hole_offset() + washer_diameter(M4_washer) / 2 + 1) + sheet_thickness(frame) / 2;
+                  idler_end - z_bar_offset() + z_motor_bracket_hole_offset() + washer_diameter(frame_washer) / 2 + (squeeze ? 0 : 1))
+                          + sheet_thickness(frame) / 2;
 
-right_stay_x = frame_nuts ? min(motor_end, motor_end + z_bar_offset() - z_motor_bracket_hole_offset() - washer_diameter(M4_washer) / 2 - 1 - sheet_thickness(frame) / 2)
-                          : max(motor_end, base_width / 2 - right_w  + sheet_thickness(frame) / 2 + fixing_block_height() + base_clearance);
+right_stay_x = frame_nuts ? min(motor_end, motor_end + z_bar_offset() - z_motor_bracket_hole_offset() - washer_diameter(frame_washer) / 2 - 1 - sheet_thickness(frame) / 2)
+                          : max(motor_end, base_width / 2 - right_w + sheet_thickness(frame) / 2 + fixing_block_height() + base_clearance);
 
 Y_belt_height = y_motor_height() + pulley_inner_radius + belt_thickness(Y_belt);
 
@@ -83,7 +84,8 @@ psu_y = base_depth / 2 - base_clearance - psu_width(psu) / 2 - (atx_psu(psu) ? a
 
 psu_top = psu_z + psu_length(psu) / 2 + (atx_psu(psu) ? 0 : mains_inlet_depth());
 
-controller_z = (height + psu_top) / 2 - controller_length(controller) / 2;
+controller_z = (height + (psu_length(psu) ? psu_top : fixing_block_height() + pi_width)) / 2 - controller_length(controller) / 2;
+
 controller_y = (base_depth / 2 + gantry_Y + sheet_thickness(frame)) / 2 - controller_width(controller) / 2;
 
 spool_z = height - gantry_thickness + spool_diameter(spool) / 2 + 10;