I tried to help you in the first few posts and you didn't seem to want to listen. So I stopped trying to help you. I am known around the world as an expert scraper and Tom Lipton and Stefan G are students of mine. They needed their techniques tweeked. I sell the Connelly book and the bottom relief groove is a simple part of scraping. No need to be a rocket scientist to put it in. Some companies cut them in with a shaper, planer, cut off saw, hack saw, air grinder with burr or thin disk, a Dremel, a sharp edged carbide or HSS scraper blade, a knife file, etc. Some factories don't relieve with a groove. It helps when you scraping the dovetail with a prism straight-edge. Many only file the edge off the riding part and never relieve it.
As you scrape a flat surface the dovetails move over and you either cut it deeper, file off the mating side or apply a wear-strip. I have a scraping class next month, come and learn how from a professional machine rebuilder who has been training people how to over my 50+ years of scraping. If you go back to You Tube and search "Richard King Scraping" You can see several shows about me and my classes. Other notable students on You Tube are Adam Booth, Keith Rucker, John Saunders, Jan Sverre Haugjord. I have taught classes at Timken, dozens of new machine builders, 7 divisions of GM, USA Naval shipyards and army depots, hundred of places and thousands of students. You can see more at my website.
http://handscraping.com/ and under testimonials You will see this.
"Ever since you instructed our first group of rebuilders, we have had numerous requests to have you back to instruct the remaining rebuilders. Your ability to adjust your class to fit our needs left a lasting impression.
Even though our rebuilders are experienced at scraping, they learned new techniques to improve accuracy and efficiency. The rebuilders had a lot of praise regarding the class and recognized your expertise as you worked along side them.
I strongly recommend King Way ... seminar for instruction in Basic 40/40 Hand and Advanced Machine scraping. It is excellent for anyone who is doing machine rebuilding or slide retrofitting."
Norm J.
Supervisor Machine Rebuild • TIMKEN • Canton, OH 44706
I am willing to help you here if you want to learn.