What tool do you use to carve the recess?
It depends, I think we all have our ways of doing it. Some use a drill and a screw driver, some a lathe. I personally use a Dremel tool in a press with a cutting bit. I’ve seen vid’s of others using a drill press to recess too, but its pretty much the same concept.
I used the technique shown in the link above. I have a small grinding head for my hand drill which I used to sharpen a heavy construction nail I found laying around. (I think they might call it a framing nail.) I didn’t get quite as crisp and neat of a cut as shown in the link but it was close and the recess mod is working great on my FH2.
Could you get a good recess if you used a flat head screwdriver?
You’d have to sharpen it. I didn’t want to ruin one of my perfectly good screwdrivers so I sharpened a nail.
Also, I have heard of FHZ’s having single side recesses, but what is in the other side?
Nothing, just stock FHZ.
The trick is to make the single recess wider than a normal recess.
usually its a recess for a pad and the other side is stock
You can schmoove ring the other side if you want.