[greggm]

How do i go about drawing a "furniture leg" with curves and coves etc or and then turn it into a rotary (A) tool path.

I have purchased 3 1/2" square cedar post to practice on so i am thinking a roughing pass with a .5" 2 flute straight router bit and then go back with a ball end mill to do the finish work

I also want to learn to do tapering and add wrapped v carve/3d carvings

a axis is along the "Y" travel ((G59 offset #6))
bob cad v23 & bob art pro x
mach 3 with 4 position tool changer

If someone could send me a sample file that will open in V23 that i can learn from or a you tube that would be most helpful.

[BurrMan]

I forgot to mention that if you needed to get better definition with a smaller tool, you dont have to do the entire thing with a smaller tool. You could just boundry off a single leaf and run a second toolpath on it also:

[BurrMan]

Be sure to set the video to run in HD and then go to full screen mode for the best picture:



Regarding the roughing, I cut it out purposfully because it didnt do what i thought, and was misguided...

[mcphill]

Great video you posted, thanks for the training!

[nomedia="http://www.youtube.com/watch?v=KCbsi5nmW8Y"]YouTube - 4th_furniture_redo[/nomedia]

[Claude Boudreau]

Mr. Burrman,

Can you tell me how you would proceed, to do some Chippendale Style furniture leg?

Are these asymetrical type of drawings unwrappable?

If not how about 3 faces Corbels?

[mcphill]

Mr. Burrman,

Can you tell me how you would proceed, to do some Chippendale Style furniture leg?

Are these asymetrical type of drawings unwrappable?

If not how about 3 faces Corbels?

I'd love to see that too. The only 4th programs I have seen are on cylindrical objects, never something "funky" that isn't really unwrappable. If that is possible, I would like to see the method. I think there is a hint in one of BurrMan's videos, where he discussed using a "VV" shape to model the square stock. He unfortunately edited that part out as I think he stated it didn't work in the video he did, but it sounds like he does have some insights on it...

[BurrMan]

Anything that will be "unwrappable" will be whats called a "developable surface"... These would be things like cones, cubes, surfaces that curve in only one direction.. Any surface that curves in more than one direction is a non-developable surface, and cant really be unwrapped without "Tearing" it, or stretching or squishing... There are specialty programs that are setup to work with flatening out non-developable surfaces to be cut in 2d, then rolled back up and welded or glued to make the solid, but thats a bit different than cutting it in a 3 axis rotary...

It will take me a bit to show, I just downloaded a basic corbel and have to set it up, but i will do it with Indexing and a combination of V-carve and various 2d and 3d toolpaths...

We'll see how it comes out...

Mike, the WWW thing you saw in the previous video, was me trying to figure out how to rough away the corners of "square stock" "WITHOUT" cutting air where it rotated around to the actual diameter that was set... The toolpath I had created was a V shape, though it would have to be an "Upside down V" to actually do it right.. A case of doing before I actually Thank!!! There could be ways to acheive it if you needed to cut many of them.. Just a matter of creating the geometry for the toolpath... Anyway...

[mcphill]

I think the "right" way to do this in BobCAD is to use the 4th axis as an indexer only. Machine one face, rotate 90, machine face 2, rotate...

[BurrMan]

I guess we need a starting point, since I dont really know furniture...

Here's a simple backplot of some V-carve and other operations to do a single face....





So if it's something like this, we can move to a next step, like flipping it for the other faces, or if 3d becomes involved, how we would do that.. Here's this file to look at.

This is a basic corbel I downloaded from internet.

[mcphill]

That's exactly what I was thinking. Now rotate it 90 degrees and do the next face. You may be able to do both side faces and just rotate 180 to do the current bottom. All depends on the details present on the two sides as it currently sits...

[BurrMan]

Yes Mike, although with 2d stuff, I wouldnt rotate the geo.. In this file you will see an added UCS. If you make it active and add more operations,tey will be cut on the 180 degree index... But this geometry is also sitting at Z 0, so a determination f the actual thickness wanted could be made and then change the features parameters to cut at the proper level for both sides. This can be done by translating the geometry up and also maing a copy to translate down, and toolpathing the 2, or justcrunching the numbers at the feature level and keeping only the one set...

If we need to use 3d toolpaths to do surface work, then the strategy needs to change to rotating the part around....Making use of boundries to constrain the toolpath... I have found that indxing organic shapes that intrude into the other index, doesnt work.. This would be me waiting for a true 4th axis.