How to Exclude Delicate Areas from Roughing?

[GollyRojer]

I'm making my brother a 30" x 30" x 1" sign using cypress. It has a slogan wrapped around a 20" diameter circle, and inside the circle is the file "Dove.3dClip" from the Clipart files included with Aspire. The dove has an olive branch in its beak. I made a vector boundary around the dove and I'm clearing the area between that and the inner circle with first .625" (5/8) and then .25 end mills. The bits go right up between the leaves of the olive branch. The branch stem is less than 1/4" thick in places. In a test run on particleboard, it snapped off in places and little was left after the roughing pass.

I would like to be able to select an area around the olive branch and tell the roughing pass to skip it, and then come back in another toolpath with a .125" (1/8). Or I could do the olive branch first, clearing far enough out that the roughing pass doesn't touch it. But the branch is part of the whole 3D Dove component. How can I separate that section of the component and treat it as a different object? I have seen instructions to "draw a closed vector around the part to separate, and use 'Split the selected component using a vector'", but I'm not clear on how to draw a closed vector around this branch. Here's what it looks like in the 2D and 3D screens. How would you go about doing this?

Olive branch closeup in 2D and 3D.

[highpockets]

I created a dove in a circle. I used the Create vector boundary around the dove. I then used node edit and cut the olive branch around the doves beak. Used the Join / Close vector tool to close the vectors around the olive branch. I then used the Offset selected vectors and entered a .125 outward offset around the olive branch. Next using Interactive Vector Trim tool to trim the offset vector to the vector around the dove. Then I selected the offset vector and vector around the dove and used Join open vectors to create a new closed vector around the dove and offset around the olive branch. This is now your roughing which will leave extra material around the olive branch.
Next to remove the extra material around the olive branch using a second roughing toolpath create a second offset just like the first and only rough selected vector (inside olive branch offset).
Now you can use your finishing toolpath as usual.

I hope this make some since.

[martin54]

I use boundary vectors the same way John has to exclude areas I don't want machined. Another option you might want to look at since you are using Aspire is Rest Machining which is a method that can be used to machine 3d parts more efficiently. The tutorial actually uses the dove model

http://support.vectric.com/tutorials/V8 ... g3D_4.html

[joeporter]

You mentioned particle board as a test piece, I think particle board is bad to snap off anyway. I really don't know if you have a problem. If your toolpath preview looks OK, then it should machine OK as long as your material doesn't chip out...joe

[GollyRojer]

Thanks, all three of you. Joe, I bet you're right, but I'm scared to try it. It's a big sign and the material was not cheap!

Martin, I tried Rest Machining first, following the video. I'm not sure what's different, but I couldn't get it to create the component from the preview with the offsets, like in the video. Tried for quite a while before giving up on that. I will come back to it later and experiment with it more.

Highpockets, that did make sense, thank you very much. It took me some more study to understand using node edit to cut the olive branch, but I got it. After that, the rest fell into place.

[Rcnewcomb]

It's a big sign and the material was not cheap!

Pink or blue insulation foam from the Big Box hardware stores may be a better test material than particle board.

[ohiolyons]

Make sure you don't get the scored pink or blue foam. People will assume there is something wrong with your work. Personal experience, I know a guy.

[Rcnewcomb]

Personal experience, I know a guy.