EVA jig showing guiderail

Picture shows base of jig which is a plank of 3/4" particle board with a guiderail made from a piece of 2x2, and a homemade cradle for my electric drill at the end. The drill is shimmed to center it with the jig using plastic shims cut from gallon milk jugs & held on with a hose clamp. I set up the drill with the sliding part of the jig on the guiderail & use various homemade levels to true it up. The sliding part of the jig holds the eva centred & you slide it onto the drill bit to drill the hole.