What did you do with your truck today, Part 3

[mick53]

I still can't decide if I should try to cut the grooves in my $280 pulley myself of take to a machine shop. She's an eight ribber. So I played with doing it today on a piece of scrap. I have the specs. It's 40 degrees with a .015 radius and spaced at .140. I have a bunch of cobalt tools that I bought off ebay and found one close that I ground at 40 degrees and then fit it to the other pulleys. If I take it in they are going to want $100-$200 and take a week or two to do it. I think I can pull this off with a little more practice. I got some chatter but haven't set the speed right yet and probably should come in at 39 degrees or something instead of straight. I'm going to order a Gates belt for comparison while I make it. I'm just using a piece of tape to measure it. I hope that works. It looks like I have about 120 degrees contact on all the pulleys. Is that enough for the alternator? I was hoping by going 8 rib to avoid a tensioner. Thank you for your time.