I recently got my hands on some 20 degree 1/8" engraving bits. I needed them to do some detailed v-carving. I “winged it” with some settings that sounded reasonable/didn’t violate the golden rule of 0.001" chips (I didn’t see any defaults in Carbide Create). Results were mixed…
I’ve since had a chance to do some trial runs in scrap and arrived at the following settings:
DOC = 0.02"
Feed = 40 IPM
Plunge = 15 IPM
Speed = 16000 RPM
I’m curious to hear what others have come up with in regards to settings. The shallow DOC was a real breakthrough for me as far as getting good results. The acceptable range of settings certainly seems to be narrow compared to the 60 degree v-bit I’m used to.
Do I understand correctly that you ended up using 0.02" per pass and the pic illustrates cutting down to 0.2" max depth ? (so did it take 10 passes ? I wondered about a possible typo)
Anyway out of curiosity I checked what I said about ballpark feeds and speeds for V-bits in the ebook, which I had derived from various posts here on the forum, and all parameter ranges match what you ended up using, except DOC.
From my (limited) v-carving experience, while the feeds and speeds matter, the quality of the cutter, the nature of the wood, and surfacing the stock before cutting matter even more to get great results.
Some of the more “stringy” woods (like oak) can benefit from doing a “scoring” kind of pass with a thin flat endmill. So say 0.01" with a 1/16th or 2mm flat bit. you might need to do an “inside offset” shape in CC to not touch the part where the V will go (but at a steep angle it is likely ok)… flat endmills do better with stringy wood, and if the line at the surface is clean already, the V bit is less likely to make stringy artifacts.
Yes this won’t get into the small corners, but most of the visible stuff tends to be on “long straight lines” of text.
also for fun, you kind of only need the shallow DOC on the last pass or two, so you could a more aggressive pass that leaves 0.02" behind, followed by another pass that takes the last bit away (which by nature then is not so aggressive)
I recommend white oak versus red oak. White oak is far less “stringy”, harder and will retain sharp edges much better. The only thing red oak has going for it, besides being cheaper, is the warmth of color. But it’s also possible to find some white oak that is hard to distinguish, color-wise.
Be aware that while “white oak” is supposed to refer to “Quercus alba” (hope I’m spelling that correctly), it is not uncommon for things to be mis-identified. Other things that sometimes get called “white oak” have names like swamp oak and bastard oak, live oak, etc. Red oak is just as confusing if not worse as I think there are more that fall into that general type (no tylosees).
