Even though YouTube seems to have umpteen million videos about machining I’ve found very few that will you show how to grind HSS bits for a metal lathe. And most of them show it being done on special grinders or with the help of jigs and accessories that most of us don’t have. These four videos by Tubal Cain, the author of many books about machining and metalworking, are among the few I’ve found that will show you how to do it free-hand on the kind of grinder most home machinists have. [This is not the same Tubal Cain who wrote more than 20 books and 200 articles about machining and model engineering. That was the late Englishman T. D. Walshaw who used “Tubal Cain” as a pen name. This “Tubalcain” appears to be a retired shop teacher living in Illinois. – Rob]
The videos are good, but not great because they’re too long. “mrpete222” doesn’t get to actually showing you how to grind a bit until the fourth video. During the first three he discusses the shapes and angles of the various kinds lathe bits using large wooden models that make it easier to see what he’s talking about. He also discusses the tool bit holders used by older lathes, which hold bits at an angle so they don’t need back rake added to them.
I’ll admit I’m not real good at grinding lathe bits because I usually use carbide inserts. But I did learn a lot from these videos including these two great suggestions:
- Use lay-out dye and mark out the angles you need to grind.
- Practice on mild-steel (keystock). It’s cheaper and grinds faster.
Lathe Tool Bit Grinding Video #1 (10:46) – Right-hand turning tool, back rake & tool holders, angle of keenness
Lathe Tool Bit Grinding Video #2 (5:13) – Facing and universal turning tools
Lathe Tool Bit Grinding Video #3 (5:39) – 60-degree thread cutting bit
Lathe Tool Bit Grinding Video #4 (8:46) – Actual grinding of right-hand turning tool