sorry for my late reply, but eh 12" im not sure, it needs to be whatever the legth of the vos32 is for slot ones.. im guessing 5 or 6" not entirely sure my self on that.... been lookin for info on it but no luck...
so uhm 2 12" alum blocks cut in half, that way theres 4 passes (3 holes per block) i really dont have the money for it right this moment, should be able to get it within the next few weeks, lemme know what it would cost you for this.... i know dangerden sells alum and copper stock, 2x12x1/2" is like 3.50 and same size for copper is 20 bux ... id perfer aluminum since 1. its cheaper, and 2. this project may fail horribly.... but im not going out without trying it
