Building plastic drawer bottom 3MF and constraining to 340mm print volume

The drawer is 345mm long but the printer maxes out at 340mm, so dialed
the length back to fit. Also added the 3MF build target to the Makefile
so this baseplate gets exported alongside the pegboard shelves.

Co-Authored-By: Claude Opus 4.6 (1M context) <[e-mail]>

Makefile

···
 
 # --- Plastic Drawer Bottom ---
 
+PLASTIC_DRAWER_BOTTOM_MODEL := plastic-drawer-bottom.3mf
 PLASTIC_DRAWER_BOTTOM_THUMBNAIL := plastic-drawer-bottom.png
+
+plastic-drawer-bottom.3mf: plastic-drawer-bottom.scad Makefile
+	$(OPENSCAD) -o $@ $<
 
 plastic-drawer-bottom.png: plastic-drawer-bottom.scad Makefile
 	$(OPENSCAD) -o $@ --autocenter --viewall --imgsize $(THUMBSIZE) --render '' $<
···
 
 ALL_OUTPUTS := \
 	$(PEGBOARD_SHELF_MODELS) $(PEGBOARD_SHELF_IMAGES) $(PEGBOARD_SHELF_THUMBNAIL) \
-	$(PLASTIC_DRAWER_BOTTOM_THUMBNAIL)
+	$(PLASTIC_DRAWER_BOTTOM_MODEL) $(PLASTIC_DRAWER_BOTTOM_THUMBNAIL)
 
 all: $(ALL_OUTPUTS)
 

plastic-drawer-bottom.scad

···
 $fs = 0.25;
 
 drawer_width = 240;
-drawer_length = 345;
+drawer_length = 340;
 
 hole_options = bundle_hole_options(
     magnet_hole = true,