@@ -32,15 +32,18 @@
 	local tool = inv:get_stack('tool',1)
 	local tech = sorcery.lathe.tooltech(tool)
 	if not tech then return nil end
 	local wkpc = inv:get_stack('workpiece',1)
+	howmany = howmany or wkpc:get_count()
 	local rec = R[wkpc:get_name()][tech][idx]
 	local outn = ItemStack(rec.output):get_count()
-	local q = howmany / outn
+	local ntimes = math.floor(howmany / (rec.mass or 1))
 	return {
 		tool = tool, wkpc = wkpc;
-		cost = rec.cost * q;
-		qty = q, outn = outn;
+		cost = rec.cost * ntimes;
+		ntimes = ntimes;
+		tqty = math.floor(howmany / outn), outn = outn;
+		gqty = ntimes * outn;
 		tech = tech;
 		rec = rec;
 		inv = inv;
 	}
@@ -64,19 +67,20 @@
 	-- obey level restrictions. TODO honor Rend
 	if (wmat and wmat.data.level or 0) > (tmat and (tmat.data.maxlevel or tmat.data.level) or 0) then
 		return
 	end
-
+	
 	local tech = sorcery.lathe.tooltech(tool)
 	local rec = R[wkpc:get_name()][tech]
 	tech = sorcery.lathe.techs[tech]
 
 	-- fill in the preview slots
 	local j = 1
-	for i=1, inv:get_size('preview') do
-		local stk
-		if rec[i] and minetest.registered_items[ItemStack(rec[i].output):get_name()] then
-			local max = wkpc:get_count()
+	for i=1, inv:get_size 'preview'  do
+		local stk = ItemStack()
+		if rec[i] and minetest.registered_items[ItemStack(rec[i].output):get_name()] and (rec[i].mass == nil or rec[i].mass <= wkpc:get_count()) then
+			local l = sorcery.lathe.get(pos, i, wkpc:get_count())
+			local max = l.ntimes --math.floor(wkpc:get_count() / (rec[i].mass or 1))
 			if tech.dmg then
 				-- TODO count remaining tool uses
 			elseif tech.consume then
 				max = math.min(max, tool:get_count())
@@ -83,11 +87,11 @@
 			end
 			if max > 0 then
 				stk = ItemStack(rec[i].output)
 				stk:set_count(stk:get_count() * max)
-				inv:set_stack('preview',i,stk)
 			end
 		end
+		inv:set_stack('preview',i,stk)
 		j = j + 1
 	end
 
 	-- make sure remaining slots are clear
@@ -185,13 +189,16 @@
 					lfac = (mmat and mmat.data.level or 1) /
 						(mat.data.maxlevel or mat.data.level or 1)
 				end
 				local ch = 65535 / dur
-				l.tool:add_wear(4 * ch * l.cost * lfac)
+				l.tool:add_wear(ch * l.cost * lfac)
 			end
-			l.wkpc:take_item(l.qty)
+			l.wkpc:take_item(l.tqty)
 			l.inv:set_stack('tool', 1, l.tool)
 			l.inv:set_stack('workpiece', 1, l.wkpc)
+			if l.rec.leftover then
+				sorcery.lib.node.insert(ItemStack(l.rec.leftover), 'workpiece', pos, user, l.inv)
+			end
 			minetest.sound_play('sorcery_clank', { pos = pos, gain = 0.9 })
 		end
 		sorcery.lathe.update(pos)
 	end;