HSS is better in stainless than carbide.
M42 is way better than M2.
Use as wide of a parting blade as your lathe can push AGGRESSIVELY.
Yeah, you can kinda sorta sharpen a tool on the belt grinder, but if you have a hard stone grinder USE IT. Its way better. Even with the wrong stone its better than a belt.
Flood coolant is the magic sauce.
Flood coolant is the magic sauce.
Flood coolant is the magic sauce.
Flood coolant is the magic sauce.
Flood coolant is the magic sauce.
I quit using flood coolant on the lathe (2.5 gallon tank) because it was always all evaporated when I went to use it. Same with the big (for me) manual mill with its five gallon tank. Now that I have a refractometer I don't have to waste so much SC520. Even if its dry I can just top it off with water from the distiller, and let it run for a while to mix it up. Then I only have to add whatever I need to get up to around 6-8%.
Today I was cutting off inserts for a mold. 11 pieces 1.5 inch diameter
416 round bar parted to 1.375 inches. Displaces almost exactly one pound of lead so a deep drop sinker can be cast in any weight they need from 1 pound to 12 pounds depending on how many inserts they stack in the mold.
I had picked up a 0.125 (1/8 inch) M42 parting blade last time and it was better than anything else I had been doing. I kept touching it up on the belt grinder, but even with the belt very tight across the platten I didn't feel it was that sharp. Today I set up an old tool grinder with green wheels and used it instead. The parting blade felt sharp. It made several cuts, but wasn't parting off quite as nice as I thought it should
Then I cleaned out the chip tray (I could barely lift it), and filled the bone dry coolant tank with water. After reaching in with my hand to stir the scum and letting it pump for a while it was reading almost 4%. I added a little more SC520 until it was read a little over 6 and started parting. Dang it.
Flood coolant is the magic sauce.
Flood coolant is the magic sauce.
Flood coolant is the magic sauce.
Flood coolant is the magic sauce.
Oh, yeah, and one more thing. Flood coolant is the magic sauce.
I started using the 416 because its a little easier machining than 304. When I got to the end of the piece of stock I was parting I was one insert short. I could have walked over to the round bar stock rack and grabbed another piece, but that was a whole 20 steps (going around stuff) away, so I grabbed a short piece of 304 that was on the lathe tool cart, chucked it up and by golly it parted just about as easily as the 416.
Flood coolant is the magic sauce. Well when paired with the right tool that has been properly sharpened.
I don't really like the angled blade holders that lock the blade in with a wedge tightened with a screw from the back. It can pivot on the pinch point, and its really only clamped at one small point. I think its time to make another coupled multi screw flexure type blade holders. I made one a while back for an insert blade, but I gave it away. I didn't like the insert blade for the work I needed it for. I do have another one, but its tiny for the old HF 7x10 mini lathe. It works though for the tiny little 1/16 blade that's in it. I guess its time to look through my bits and pieces of steel and see what I have to use to make some blade holders.
FYI: I have a number of bench grinders, but this was the first time I used this "tool" grinder. Its a Harbor Freight 46727. At first glance it kind looks like a bench grinder on sterioids, but its WAY better setup for tool grinding. They don't sell it anymore. I think my dad bought it on a closeout special. This was the frist time I used it, and I have to say I really liked using it. I'll probably run these green wheels for a while, but if I can find a CBN wheel for one side and a diamond wheel for the other side I could see it become my favorite grinder. Yep. Its discontinued, but Grizzly sells a very similar Grinder. H7762 Except for the paint, and that the Grizzly doesn't come with a stand, they look like the same grinder. In any case I'm sad to see Harbor Freight no longer sells it. It definitely seems like it was one of their hidden gems.