yes you are doing something wrong
step 1 is click the middle and put a Mithril ore in it... without ore the other parts don't work
step 2 is click the mold holder and place one of your molds in
at all time you need lava before dropping the hammer to make the item [wheel adds lava]
after every thing else is done then pull lever to release mold holder... rinse and repeat until all Mithril ore is used up
