they're not hard to make at all. Go to your local hardware get some 5/16 washers which are very close to the finish product. You need to drill put the center hole a tiny bit and sand one side down a tiny amount (only one side). I used 400 grit wet/dry sandpaper laid on a good solid flat surface and carefully said the one side try to make sure that I kept it flat. The only tool items that come in handy are a drill press, a hand drill will do but the drill press is better and a dial caliper which helps make sure the dimension are OK. I was going to make some to sell to those that wanted some but a couple of other GTA members mentioned they had already started the process of making them. Still have not seen any mentioned on here yet!! Guess maybe I should have made mine for those that are still waiting!!