Just finished my first large 3d

[Ken Sully]

Just finished my 3D spine 18" x 36" in Oak.
All went well but seems to be a lot of sanding marks left from the 1/8" ball nose bit.
Questions:
Is this typical for Oak?
I did the 3D at 45 degrees with 8% overlap. I did see you could create a second
tool path at 90 degrees. Should I have done that?

The machine lines were not excessive but took some time, not sure what I should have expected
Any advice would be great
Thanks

P.S. Does this Bot make COOL stuff!!

[mikeacg]

Pictures please! It will be easier to diagnose any issues!

Mike

[Ken Sully]

The lines went pretty much all the way across the 3D carve.
You don't see a lot of machine lines left because I sanded most of them off.

[Ken Sully]

This is the final cut file detail
Sorry for the photo darn PC won't print screen for some reason

[bleeth]

That's about normal. You can cut it down some with a finer stepover but the sad truth of 3-d work is there is tedious hand clean-up afterwards.
You can make that part somewhat easier with flap sanders but need to go carefully so as not to lose detail.
There are other things such as doing an area clear with a flat bit of any flat background areas and confining the ball nose to the relief only that also lower the sanding required.

[adrianm]

Try doing the 3D finishing cut in line with the grain. That's what I do and I don't get marks like that.

[rcnewcomb]

I agree with Adrian, going with the grain in Oak will yield better results.

You may also want to check that your spindle/router is plumb.

[dlcw]

Ken - when I do 3D work, I do the roughing pass across the grain. The finishing path is always done with the grain - no matter what type of wood I use. I get very clean results.

My stepover (depending on the size and detail requirements of the project) are 8%. For smaller fine projects, I will go as low as 4% with 1/16" ballnose. It takes longer to carve but SOOOOOO much less sanding is required. You just need to figure out if your machine time is more valuable or you hand sanding time is more valuable. Tradeoffs required here.

This is one of those things you will learn with experience. Keep asking the questions though so you don't reinvent the wheel that has already been invented by a Shopbotter out there somewhere.

[Ken Sully]

Thank you all for your feed back.
Have some more oak and will try your suggestions.
Going to try the last supper in Blood Wood. The grain looks a lot like mahogany.
I will use 4% with a 1/16 ball nose

Thanks to all of you for reducing repeat mistakes.
Darn wood is getting expensive..... wonder if I could dry out some dirt and carve it, after all they used to make houses out of dirt!!

[feinddj]

Going with the grain is important but also make sure that your model resolution is set to very high and your workspace is no larger than your model to get the best result.

D