I ventured into 3d carving yesterday with less than satisfying results. I felt the image was strong and the detail was good in EstlCAM and the rough detail was recongnizable, but the detail was lost in the finish step. I was using a 3.75mm ball end mill using a spiral cut for the roughing cut and a horizontal cut for the finishing pass.
I am fairly new to this as well but I give advise on what I have learned so far. Everything I have done on my MPCNC since the crown test has been 3D carving.
I have three bits of advice.
I would use the X or Y pattern for the Roughing and the circular pattern for the Finishing. Because the roughing cuts don't matter as much so they can be done quickly. Then let it take the time to make the finishing cuts smooth.
In the 3D machining window in Estlcam under the finishing side there is a stepover setting that defaults to 15%. That is essentially saying that it will make a cut then move outward 15% of the diameter of the bit for the next pass. In your picture you can see the lines where it moved a little then cut again. If you set that down you will get much smoother surface.
Use a smaller bit. If you are going to carve some 3D objects that are small with fine detail then you need a smaller bit. You should consider doing a tool change between roughing and finishing passes. OR just make your cuts bigger on bigger pieces of wood.
Here is one of my failed test carvings. I was using a 3.10 mm ball nose bit the entire time. This board is a scrap 1 X 6 I think. I know it was 114mm wide and 500 mm long. I made a mistake in Estlcam when I setup the size so I didn't use the full width of the board. So it shrunk down smaller than I wanted. As a result the bit couldn't fit between the letters for the words "Merry Christmas." But I used 2% stepover in my finishing passes. So it is super smooth!
It’s an interesting process to say the least. I will change the step-over value of the bit.
The size of the carving was 6in x 6in and it seemed that the background which showed up as a deeper blue was well defined (the antlers to be specific) on the image but didn’t really show in the carving.
