How to finish a carving?

[CaesarS]

Hi,

I've searched the forum but didn't find relevant topics.

How would you finish a cut carving?

I know there is the roughing cut, then finishing cut.

However there is still a thin roughness to the cut part (line striations along where the finishing cut was made).

I have not worked with 3D carving before, it's been 2D cutting until now.

Thank you, Caesar.

[NormanAlbert]

Hi: As you are finding out, the size bit and the step over determines how much sanding you'll need to do. Yes, sanding, everybody's favorite job. My carvings in the 6x6 range I'll use a 1/16th ball nose with an 8 % step over, sometimes depending on the details in the carving I'll go down to .04 ball nose. Larger carvings I'll use from .0625 up to .125 ball nose. Again with 8 % step over. On some woods grain direction can make a difference. You just have to try things out. You'll find with the cnc that harder woods are much better to use as opposed to soft woods. Have fun. Norm

[CaesarS]

Thank you Normal, good to know there's no special magic in use other than elbow grease

[scottp55]

Caesar,
You May want to play with smaller stepover also. Adds a lot of time, but on some small/deep/intricate pieces that are almost impossible to sand without loosing detail, it actually saves you time and can really make a piece.
In the 2 pics they were unsanded and had only had a stiff boar bristle brushing.
3M Radial Bristle Discs in a 400G will take off stubborn Fuzzies and won't disturb fine detail I've found.
Maybe try the identical file in a couple different stepovers in a small size to compare?
Gone as low as 1.5% just to compare myself, but then I'm all tiny stuff.(currently in the 3-6% range here)
Find what your happy medium is.
scott

[dhellew2]

In addition to the bit size and step-over the characteristics of the wood will determine the end result. Ring porous woods such as oak will not be as smooth as straight grained wood like redwood and red gum. Oily/resinous woods such as southern pine cut better than white pine or aspen which both leave lots of fuzzies.
All woods work, some just require more work....

Raster cutting with the grain helps hide the stepover and produces less fuzzies in most woods.

I prefer a mop sander because it will remove much of the fuzzies and some of the stepover without changing the profile. They are available from Klingspor for use on a bench mount mandrel or in a drill or drill press.

For the mall areas I like the small plastic sanding wheels for dremel or other such tools (I use pneumatic pens from Harbor Freight)

Dale

[CaesarS]

Thank you!

I will try all the suggestions.

Best, Caesar.

[scottp55]

While you're at it Caesar, it doesn't hurt to think outside the box.
For instance, that particular Owl was finally cut using an offset toolpath after 5 tests, as the centerpoint of the design was on the Owl's breast and first cut was only .1" deep and then all the rest was small stepover that the bit had enough cutting edge length to handle. Same with Domes(Thanks Michael T.). You don't get alternating climb/conventional passes either.
Also, the Loon buttons are now all cut against the grain in one pass, as the loon's neck was unsupported end grain and Bloodwood though very dense can be brittle. I lost tiny chips out of the neck cutting with the grain on 2 out of 3 times, and zero out of 30 when cutting against grain.
I forgot to note I DID take a second pass on all with grain Loon cuts as the fuzzies compared against the against grain one just weren't comparable.
Play with some small test pieces for yourself before writing stuff in stone:)
scott