Thank you Javand - that really makes a lot of sense!
I'm in the process of trying to soak up as much info as possible (and accumulate tools & material), so I can make my own knives. Conversations and threads like this have a value to newbies like me that can't even be described!
With regards to a cutter to create a nail nick, what price would you (or anyone) consider reasonable, and do you consider "exceedingly expensive"? I'm just trying to wrap my head around this perspective.
If I were trying to do it with a dovetail cutter, to get the appearance I'd expect, it would need to be a 3-4" diameter at the cutter tips. If you had to price that from US HSS let alone solid carbide, I'd expect that to be many hundreds, if not a thousand dollars. I've never seen any that large in recent years.
The other option would be a large insert cutter, but that also, of any quality, would likely be that much or more.
At that point, what's the advantage, if ever there was? The fly cutter, can yield excellent results, and single point cutting tools usually offer excellent finish quality.
This is not a question of metal removal efficiency here, fly cutters are readily and cheaply available, and so are toolbit if you know where to find them. You should be able to buy a cheap fly cutter and a good toolbit for less than $100, and you can make a flycutter with only low to moderate experience on a mill.
One could easily argue that a large angle or double angle cutter on an arbor, would make *much* more sense here. There's plenty of great, larger diameter ones sitting around not being used much anymore since most of the horizontal knee mills are also collecting dust. In fact, I've got a pile of them. Either way though, any multi-point cutter, is going to be difficult for most knifemakers to sharpen when the time comes, they'll have to send it out, or replace it. Single point tools, are very easy on the other hand, and we've all mostly got the tool (belt grinder) to do it easily.
Just to give you some price perspective, I run a small solid carbide US produced (harvey tool) 1/2 diameter dovetail cutter, for cutting integral dovetail liners/bolsters for my slipjoints, retail price on this is around ~$180.
For cutting nail nicks, in order to get a nice wide swooped nick you need a shallow angle, and a large diameter, otherwise you'll cut too deep before the nick is wide, you can't feed the cut longer either, as that destroys the shape. IMO, bare minimum is 3-4", I personally prefer 6-8" and around a ~30(60) degree angle, 45 is way too sharp, and you end up with either a very thin deep nail nick, or one too small. That's a matter of preference though. When I first started trying to figure out the best way to do it with a stone, I was recommended 3-4" diameter and 45 deg, this looked like crap to my eye, and it takes a very particular type of stone to be able to hold that angle with a sharp edge. I spent months, and many hundreds of dollars on stones until I got something that works the way I expect it to.
Here's an example of what I like mine to look like:
