Index: export_stl.c
===================================================================
--- export_stl.c	(revision 28922)
+++ export_stl.c	(revision 28923)
@@ -181,36 +181,6 @@
 	return 0;
 }
 
-TODO("this is the same code as in g-code and probably openscad has a version too - centralize");
-static pcb_coord_t pcb_board_thickness(pcb_board_t *pcb)
-{
-	pcb_layergrp_id_t gid;
-	pcb_layergrp_t *grp;
-	pcb_coord_t curr, total = 0;
-
-	for(gid = 0, grp = pcb->LayerGroups.grp; gid < pcb->LayerGroups.len; gid++,grp++) {
-		const char *s;
-
-		if (!(grp->ltype & PCB_LYT_COPPER) && !(grp->ltype & PCB_LYT_SUBSTRATE))
-			continue;
-		s = pcb_attribute_get(&grp->Attributes, "stl::thickness");
-		if (s == NULL)
-			s = pcb_attribute_get(&grp->Attributes, "thickness");
-
-		curr = 0;
-		if (s != NULL)
-			curr = pcb_get_value(s, NULL, NULL, NULL);
-		if (curr <= 0) {
-			if (grp->ltype & PCB_LYT_SUBSTRATE)
-				pcb_message(PCB_MSG_ERROR, "stl: can not determine substrate thickness on layer group %ld - total board thickness is probably wrong\n", (long)gid);
-			continue;
-		}
-		total += curr;
-	}
-	return curr;
-}
-
-
 static void stl_do_export(pcb_hid_t *hid, pcb_hid_attr_val_t *options)
 {
 	const char *filename;
@@ -240,7 +210,7 @@
 
 	/* determine sheet thickness */
 	if (options[HA_ovrthick].crd > 0) thick = options[HA_ovrthick].crd;
-	else thick = pcb_board_thickness(PCB);
+	else thick = pcb_board_thickness(PCB, "stl", PCB_BRDTHICK_PRINT_ERROR);
 	if (thick <= 0) {
 		pcb_message(PCB_MSG_WARNING, "STL: can not determine board thickness - falling back to hardwired 1.6mm\n");
 		thick = PCB_MM_TO_COORD(1.6);