@@ -16,8 +16,47 @@
 		if not rs
 			then recipes[def.input][def.tech] = { def }
 			else rs[#rs+1] = def
 		end
+	end;
+	register_metal = function(def)
+		local parts = sorcery.data.metals[def.metal].parts
+		local out = ItemStack(def.output)
+		for _, ty in pairs {'ingot', 'block', 'fragment'} do
+			local pt = parts[ty] 
+			local ptc = sorcery.itemclass.get(pt, 'metal')
+			if ptc and ptc.value then
+				if def.mass <= ptc.value then
+					local mass
+					local vfc = ptc.value / def.mass
+					if math.floor(vfc) ~= vfc then
+						for i = 1, 50 do
+							local v = vfc * i
+							if math.floor(v) == v then
+								mass = i
+								vfc = v
+								break
+							end
+						end
+					else
+						mass = 1
+					end
+					if not mass then
+						log.err('tried to register a lathe metal recipe for',def.output,'but the mass ratio',vfc,'for part',ty,'has too many digits to the right of the decimal place')
+						return false
+					end
+					sorcery.lathe.register {
+						input = pt, mass = mass;
+						tech = def.tech, cost = def.cost;
+						output = {
+							name = out:get_name();
+							count = out:get_count() * vfc;
+						};
+						leftover = def.leftover;
+					}
+				end
+			end
+		end
 	end;
 	tooltech = function(tool)
 		if type(tool) ~= 'string' then tool = tool:get_name() end
 		for g,t in pairs(sorcery.lathe.tools) do
@@ -49,9 +88,9 @@
 		lfac = (wmat and wmat.data.level or 1) /
 			(tmat.data.maxlevel or tmat.data.level or 1)
 	end
 	local ch = 65535 / dur
-	local wear = 2 * (ch * rec.cost * ntimes * lfac);
+	local wear = (ch * rec.cost * ntimes * lfac)
 	return {
 		tool = tool, wkpc = wkpc;
 		cost = rec.cost * ntimes;
 		wear = wear;
@@ -84,8 +123,16 @@
 	end
 	
 	local tech = sorcery.lathe.tooltech(tool)
 	local rec = R[wkpc:get_name()][tech]
+	if not rec then
+		for g,v in pairs(s_wkpc:get_definition().groups) do
+			local gs = R['group:'..g..'='..tostring(v)] 
+			local gg = R['group:'..g] 
+
+			rec = (gs and gs[tech]) or (gg and gg[tech])
+		end
+	end
 	tech = sorcery.lathe.techs[tech]
 
 	-- fill in the preview slots
 	local j = 1
@@ -155,9 +202,9 @@
 		i:set_size('preview', 8);
 		m:set_string('formspec', [[
 			formspec_version[3] size[10.25,8]
 			list[context;tool;1.25,1;1,1]
-			list[context;workpiece;2.75,1;1,1]
+			list[context;workpiece;3,1;1,1]
 			list[context;preview;5.25,0.25;4,2]
 			list[current_player;main;0.25,3;8,4]
 
 			listring[current_player;main] listring[context;workpiece]
@@ -176,8 +223,17 @@
 			if tech and (s_wkpc:is_empty()
 			or (R[s_wkpc:get_name()]       ~= nil and
 				R[s_wkpc:get_name()][tech] ~= nil))
 					then return stack:get_count() end
+			for g,v in pairs(s_wkpc:get_definition().groups) do
+				local gs = R['group:'..g..'='..tostring(v)] 
+				local gg = R['group:'..g] 
+
+				if (gs and gs[tech])
+				or (gg and gg[tech]) then
+					return stack:get_count()
+				end
+			end
 		elseif list == 'workpiece' then
 			local s_tool = inv:get_stack('tool', 1)
 			if R[stack:get_name()] then
 				if s_tool:is_empty()