- Joined
- Aug 3, 2017
- Messages
- 2,437
Traditional carbide inserts particularly the cheap ones!) aren't particularly good at cutting. I chased my tail for a few years with them before my bigger lathe (but too low RPMs for carbide!) forced me into HSS. I didn't really read the HSS grind thread (saw the pictures a bit?!), and still make some pretty darn good bits, particularly for hobby use. Cut enough top-relief to make it 'sharper' for your material than 90 degrees, cut enough relief off of the other two sides so it doesn't rub, and go to town. Use a diamond/stone lap if you want, but I'm not sure it makes a difference.
Since I switched to HSS, feeds/speeds charts are way less important, since you can clearly tell when you've gone too fast (AND its only a few mins on the grinder to fix!).
The only downside to smaller bits is a lack of rigidity and smaller 'length' out of the tool holder. With a smaller lathe, this is a lesser problem for you in both regards.
Since I switched to HSS, feeds/speeds charts are way less important, since you can clearly tell when you've gone too fast (AND its only a few mins on the grinder to fix!).
The only downside to smaller bits is a lack of rigidity and smaller 'length' out of the tool holder. With a smaller lathe, this is a lesser problem for you in both regards.