Nathan the Machinist
KnifeMaker / Machinist / Evil Genius
Moderator
Knifemaker / Craftsman / Service Provider
- Joined
- Feb 13, 2007
- Messages
- 15,666
Very cool dagger Nathan. I think I remember seeing this one some time ago -- maybe on Shop Talk (which is probably where my question belongs too) -- but, can you provide any detail on how you ended up utilizing the EDM stones on this project?
Erin
Erin,
This is what it looked like when it came off the mill.
I'm a decent machinist, so the machined piece was already pretty close to what I wanted without a whole lot of extra material to remove. However, it has a lot of different kinds of cutter marks and imperfect details. Normally I would take something like that to the grinder to finish it out. However, the complexity of the geometry and my desire to maintain crisp accurate detail led me to a different approach. The first thing I did when it came off the mill was to clean it up a bit with a smooth single cut file. Then I started with 220 grit stones that I shaped with a bastard file and I got to work refining the shape and scrubbing out the tool marks. By far this was the most difficult and time consuming aspect of the job. From there I progressed through the stones and paper, ending at 2000 grit before buffing with green, white and pink. Very little buffing actually.
EDM stones can be had in different materials and hardness. With soft coarse grit cutting the fastest and harder finer less friable cutting slowly but accurately. They can be shaped with a file to fit the surface you're stoning and will conform to the underlying geometry after a little scrubbing. This allowed me to maintain sharp detail running down the length of the blade and smoothly contoured organic surfaces without waves and undulations. It took me many hours to finish the steel after machining it to get the finished work into what you see. Though I'm sure someone like Mr. Imel could do the job much faster (and better) than me.