Do you think that one could take a really interrupted cut - cutting the OD of automotive crankshaft counterweights to a smaller OD - in forged EN-19 hardened steel? The hardening is a surface treatment (nitriding, or equivalent), but I suspect the steel is damn tough. I know it can be done, because I've seen the end result, but could I do it with a SB 16" lathe? I was thinking low rpms and 3/4" HSS tool. Diameter of the OD is about 8" or so.
Brian
You won't touch the webs if they've already been nitrided. It's rock hard. Even on the raw billet it's a tough cut for a normal lathe. You can bugger the bearings and gears fairly quickly. We made a few billet cranks some years ago from scratch and the offset cuts needed a really big lathe and plenty of power. Still shook the floor a fair bit.
Dave Baker - Puma Race Engines
Might simply taking an angle grinder/dremel to remove the coating on the bits where the tool will impact the work, work?
Once you get under the hard coat, it shouldn't be too hard. (?)
Alternatively, some means of mounting the angle grinder (and lots of protection for the delicate bits.) may take care of it in short order.
I was thinking more in terms of genning up some sort of belt grinder for the toolpost. I've seen something similar that gunsmiths use on gun barrels, you'd just want a coarser grit belt. Way covers needed for sure.
Stan
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