are you not missing a dowel pin in the fixture to aline it?, i know your clamp has 2 screw and that also helps, but it could get on skewed with only two pins in the beginning ? i might not be a problem, i just saw it and wonderet
Impressive. I just tried doing some hard milling using a recipe I saw from Aaron Gough on some of his recent Instagram posts. He's using a .06 rad 6 flute end mill from maritool. It's pretty cheap compared to many end mills, so I got it and thought it worked really good. If you can change things to be able to use a bigger radius, it might help with the surface finish, but honestly the surface finish you're getting looks amazing. I don't think it's bad too flip the blade over multiple times surface grinding. If you take too much material off of one side, more stress is relieved in that side, but not the other. Which can cause it to potato chip. You might be having the same problem if you are removing most of the material on one side in the mill. You also have to manage heat. If you're taking a bunch of passes on one side, you might be causing the material to expand which can create strange shapes. Doing things like not putting the blades on the magnet long-wise can help. By taking more shorter passes, it can reduce heat build up. People often split the difference by putting the part at an angle.
Yew hardmilling is pretty sweet. At first I was going to slow and breaking a ton of stuff. Like realllllly slow. 2+ hr for one side. Yea im still learning on the grinder. The biggest problem with flipping (that I've found) to much is you might introduce something that knocks the parallelism out of wack. What you're saying is true though.
@@split141x Yeah, if you go too slow, you're letting heat build up. It's like if you've ever slowed down pushing wood through a table saw and it leaves burn marks. Or worse you aren't feeding fast enough, so the chip you're trying to create is thinner than the edge of the tool and you're just rubbing. Gough called 4500rpm, 72ipm with a 0.01 stepover " a "semi-finish pass." Before that step, I did an adaptive with .015 axial stock left. Not sure what he does. For me with my less ridgid and accurate tormach, it ended up mirror-like. It took around 5 minutes for one bevel. He says it takes 90 minutes for both sides machining. He's still feeding fairly fast, but with more stepovers. He says he does the plunge line at 7500 RPM, 50 IPM, and .0001 stepover! I'd guess that's similar to how he finishes the rest of the blade, but maybe a little less crazy thin stepover. 90 minutes is better than 2+ hours a side, but still seems crazy to me. I want to do hard milling to save time from finishing things by hand, but if you can get to nearly a mirror in a few minutes, it seems like it should only take a few seconds to get rid of the tool marks by hand. But I guess I haven't actually tried that part yet. Just harder for me to understand if the extra machine time and tool wear is worth it.
I would say hardmilling is worth it, if you require the bevels being 100% accurate. The finish is also better than if you milled the bevels soft and than heat treated. I will say tool wear is not as bad as you may first think. I get really great tool life out of my 3/16 tool. Have to be radius tools though, square chips rather fast. I'll do an adaptive rough, semi finish, than a full finish. Getting great results. I'm running around 450 sfm. Every steel is widely different as far as how hard you can push it. Than there's also your heat treat and if it's correct. 58hrc compared to 62hrc is a world of a difference when it comes to feeds, speeds and tool life. I don't every plan on ever milling bevels soft. The other features are fine to mill soft. Doing the bevels hard leaves an incredible finish, and hand sanding my two angled blade surfaces would be a nightmare. All personal preference obviously. :)
