Fix smooth rod dimensions

diff --git a/box_frame/doc/dimensions.md b/box_frame/doc/dimensions.md
index ff6b541..9b83759 100644 (file)
--- a/box_frame/doc/dimensions.md
+++ b/box_frame/doc/dimensions.md
@@ -29,12 +29,10 @@ Y Smooth rod + 30mm, so *430mm*. May be longer.
 ## X axis
 You need 2 smooth rods
 
-### X axis smooth rod is sum of:
- * workarea (200mm)
- * x carriage width (85mm for box carriage, 58mm for single plate)
- * 90 mm inside X end parts
- * for dualhead extruders, distance between hotends (70 for two extruders on box carriage)
-For 376mm minimum with box model carriage. Its also box width minus 3 cm, so at least *340* for single plate, 450 for default box. May be longer.
+### X axis smooth rod
+is box/plate width plus 25mm, so *395* for single plate, 475 default box. May be longer.
+
+Working area will be at most box width - 170 for single extruder and box width - 270 for dual extruder
 
 ## Z axis
 You need 2 smooth rods and 2 M5 threaded rods