So I've been fiddling around with grinding my own HSS lathe bits lately mostly using the old South Bend pamphlet that I got here:
http://dale.chatham.org/Interests/MetalWorking/HowToGrindLatheTools.pdf
It's been something that's been on my "list" for years - inserts are great, but I like to know about lo-tech methods too... and I suspect that the price of inserts won't be dropping any time soon. I've intentionally been making some "bad" ones so I can tell the difference between bad and good cuts in different metals.
Actually, I'm finding the "bad" ones easier to make, at the moment! :-\
One thing's got me stumped, though. Nose radius. For the life of me, I can't seem to get a uniform nose radius on my tools - they generally come out... well..... lumpy. Non uniform. And certainly not to any specific radius known to man.
Barring some sort of jig, is this just one of those "experience things" I'll get better at? Or is there a trick to it?
Also, is it better to grind the nose radius parallel to the angle of the front clearance (i.e. after the front clearance, so that the nose radius can be seen down the relieved front edge of the bit?) Or before the front clearance so that the nose radius is only at the very top edge and fades as you move down the bit?
http://dale.chatham.org/Interests/MetalWorking/HowToGrindLatheTools.pdf
It's been something that's been on my "list" for years - inserts are great, but I like to know about lo-tech methods too... and I suspect that the price of inserts won't be dropping any time soon. I've intentionally been making some "bad" ones so I can tell the difference between bad and good cuts in different metals.
Actually, I'm finding the "bad" ones easier to make, at the moment! :-\
One thing's got me stumped, though. Nose radius. For the life of me, I can't seem to get a uniform nose radius on my tools - they generally come out... well..... lumpy. Non uniform. And certainly not to any specific radius known to man.
Barring some sort of jig, is this just one of those "experience things" I'll get better at? Or is there a trick to it?
Also, is it better to grind the nose radius parallel to the angle of the front clearance (i.e. after the front clearance, so that the nose radius can be seen down the relieved front edge of the bit?) Or before the front clearance so that the nose radius is only at the very top edge and fades as you move down the bit?