lizardking7750 said:
I already paid a little bit of money for a down payment so.......
What a man would do- and it sounds like you want to be a man about this- and good for you on that- it's just too easy to take the punk's way out these days and say "It's not MY fault!" but that's BS and you and I both know it, right?
Call the machinist
ASAP- tell him to stop work, better yet go there in person, if he's unscrupulous he'll throw them on and be working them before you get there and then you're out at least the deposit.
Anyway, if he hasn't started work on them yet, get your deposit back less a generous 15% for his time and trouble (this shouldn't be necessary, but shows you're not out to screw anybody). If he's a decent guy, he'll refund you all your money if no work was done.
If he's started work, then your options are limited to paying for what he's done, abandoning them or seeing the whole thing through and paying for a pos head to be modified.