Have you thought about getting a pan, muffin tin or squarish thing as a mold and pouring the hot wax in? You could always just break or cut out peices. I know that we always used muffin tins when we were younger to make new crazy colored crayons. You could also get some pvc piping and pour it in. I would but some sand in a coffee can then place the pipe standing in it then pour.
another cool way to make it and have it three sided is to rig up a disposable baking pan and fold it a bit then pour in the way.... does that make any sense?
the problem with using muffin pans is we need them big enough to use and use fast. I mark 5 6m boards a minute and thats wearing gloves (splinters suck!) so they need to be fairly large and easy to use
I know that they make XXL muffin pans. In the states theyre known as Texas sized (fairly stupid if you ask me). You could pour them into the tin half way then break them in half. i do this with my nieces crayons and when i was younger I would do it with mine. You could also go star shaped muffin or cookie cutters and you'll have several different points