So if there was ever a topic that deserved to be in “beyond the manual” – I’m pretty sure they aren’t ever going to offer proofgrade skulls.
Things I did right:
Got the non-crumb-tray height correct with new spacer blocks.
Settings were 1000/30/270lpi. Seems good, nice dark engrave…
Things I didn’t do right:
The design (vector) was way too intricate, the finer lines didn’t even mark. In hindsight, this is a no-brainer, some of these lines were about a kerf thick. Brain took a back seat to “MINK SKULL ENGRAVE WOOHOO” inner voice.
Attempted to engrave a second time at 600/30, thinking maybe the finer lines would get more love and start to show. This turned out to be true but the detail got overburned and now some detail was lost in the larger engraved areas.
This is only my second skull attempt, so I figure a screwup is part of the process. I will dial it in next time, redesign the engrave to have bolder lines and probably start at 600/30.
I’d suggest much lower speeds, and progressively work your way up in power, and additional passes to reburn the material.
Additionally separating the artwork into different layers based on design features (kerf width, thickness, level of detail etc) to enable reburning areas that didn’t come out dark enough without overburning other areas.
Do you hang them in a tree? When I moved into my house there was a deer head hanging in the tree just on the neighbor’s side of the property line. Then it was a head with strips of hairy skin hanging off it. Then just a skull. It was a conversation piece.
You can also clean a skull by putting it in bucket with a solution of water+borax for 2-4 days. Don’t ask how I know this
As to settings for bone, my experiments were over a year ago on the PRU. I haven’t done any more since then, and settings have changed quite a bit in the interim. I sent some of those same bone beads to @dwardio , and his results were a bit better than my own. He shared his settings here if you’d like a rough guideline. IIRC, our settings were quite similar, except that he used a higher LPI.