August 25, 2011
January 4, 2009
We didn't have our granddaughter this weekend so I did a lot of writing for MachinistBlog and spent a good amount of time in my workshop. I continued to work on my HMEM EZ-Build engine but my progress has come to a halt. I need to ream the 1/2-inch diameter cylinder and my mini-mill has no where near enough height for my reamer. I decided the best solution was to shorten it, but it's a high-quality American-made one. So I'm going to order an $8 import from Enco and shorten it instead. I have to order some other things anyway and I just got the promo code for free shipping on a $25 order.
BTW, for awhile now Enco's been sending the free shipping codes for $25 orders to my Gmail address and the $99 ones to my Yahoo one. I'm thinking that I've taken advantage of the $25 code too many times with the Yahoo address and they're trying to discourage that.
So, while I'm waiting I decided to make the "Contrary Finishing Tool" that Bob Bickerson wrote a nice article about that shows how to make one. It's a lathe bit that is suppose to give you a very fine finish, something I need for the auto probe I'm making (again) for my CNC mill. I need to make the end of the probe a very precise diameter with a nice finish and I thought I'd give the contrary finish tool a try, which I've been meaning to do for at least a year. I can get a really good finish with carbide inserts on my 7x12 lathe, but I'm not having as much success (yet) with my new 8x12 lathe.
My back up plan is to try my hand at tool post grinding. I just bought a suitable grinder I can mount on my tool post.
Anyways, I made Bick's tool and it was easy. I tested it on some drill rod and it seems to work great. You can take off very fine shavings and get a very nice finish. Only I wish I'd used a 1/2-inch blank instead of a 5/16-inch one for the 7x12. I used the smaller one because it wouldn't take as long to grind and I wouldn't have as much time invested if I screwed it up. It's not a big deal. I need more practice grinding HSS tool bits.