Can a countersink bit be used for v carving? I bought some on clearance at lowes.
I wouldn’t try it. I’ve never had good luck in those bits lasting very long even being used the way they’re supposed to.
It will probably remove some material. Look closely at the tip, and imagine it spinning, and moving laterally through material, is it going to be bluntly pushing material out of the way, or cutting it? A drill, for example, has a flat spot at the very tip, where it doesn’t actually do cutting, so they make terrible mills.
I’m pretty sure they will do a good job at countersinking though. Leave them all over the place, so you’ll be more likely to countersink 
I am always looking for one, and then deciding not to use one when I can’t find it in 60 seconds.
Just used a countersink bit today for like an hour, well not for carving, but for what this bit is actually designed. I too don’t think this will work for milling/engraving.
Looking at this bit: https://shop.v1engineering.com/collections/sharp-stuff/products/1-8-45-degree-v-bit
I saw this video on YT from a company that sells those expensive V-style saw blades -> https://www.youtube.com/watch?v=OiETlYskTrY
Is a bit like this (with 90° tho) sufficient to carve acrylics so you can bend it like in the video? I didn’t mill acrylics with my mpcnc yet at all.
@SQLException, I don’t know if anyone’s tried. The real trouble will be getting the depth nearly perfect. If you got that worked out, then yeah, a 90deg bit designed for milling would do the trick. I haven’t done plastic yet, but it has it’s own special problems, specifically because it can gum up if it gets too hot, or crack if it’s pushed too hard, so you have to find the right medium.