brianpgriset
Well-known member
Well I talked about doing this a long time ago, and things are finally happening. Infact, the project is about 75% done. This started as an 8" diam. by 3" wide hunk of 4140. I modeled up some designs in SolidEdge, picked one, then wrote the NC program in FeatureCAM. Finally last week I set up the stock on the Millport 3 axis machine and got it running. About 20 hours later and you can see what I got. Actually it was a bit rougher than that, I chucked it in a 4 jaw on the Cincinnati lathe and cut a few of the radius's and some other small things. The finish is rough right now, but thats because its not done! I also (lucky me) have access to an industrial furnace, so this is going to be hardend to about 50 HRC later this week or next, then finally I'll rechuck it in the 4 jaw, make final cuts on the bearing pockets and working surface to ensure low runout, and polish the whole thing to a mirror shine.
I'll post some more pics when its all done. Should be a couple weeks.
I'll post some more pics when its all done. Should be a couple weeks.
but I have finally hardened and cut bearing pockets for the upper wheel. See the pics below (including one with my wheel and the set of 6 lowers I made). I flame hardened the wheel myself using 2 O/A rigs with rosebuds and a quench in a bucket of oil. I am totally unsure how well it hardened up. I can tell you it is harder than the original 4140 I used to make it so thats a good start. I am not planning on tempering it, as flame hardening usually produces a hard shell around the area that was heated, and the material underneath still has the ductility you desire, so it should be ready to roll right now. Honestly, it really shouldn't matter much since 4140 is already harder than normal mild steel in the unhardened state. As long as I remove the reinforcment or "proud" of welds, and sand flame or plasma cut edges before wheeling them it should never ding. Besides I'd imagine it gained some sort of hardness.
