Excessive Carving in Finish Pass

[jmdodd95682]

I have a project which uses VCarve Desktop to carve out the 4 sides of a box with box-joints. All 4 sides are carved from the same job board (with a small separation). The sides are then manually removed and assembled into box using the carved box joints. Its a 2.5D kind of project.

My problem is that the Finish pass insists on moving the tool over the entire model even though 90% of the model is flush with the surface of the job board. It blows up the run time to 2.5Hours for a small box. I seems independent of where I set the modeling surface. I've attached the images of the imported model and the tool path for the Finish pass to explain it better.

How do I get the finish pass to NOT move the tool over the part of the model which is flush with the top of the job board?

[Adrian]

Why are you cutting that as 3D job? Looks all 2D to me.

If you really want to do it as a 3D job then you can use vectors to limit the machining area.

[martin54]

+1 on what Adrian has said, you can cut that much faster using 2D toolpaths

[TReischl]

...... I seems independent of where I set the modeling surface. ......

Yes, it is independent of the modeling surface. It IS dependent on vector boundaries.

[jmdodd95682]

Thanks for the feedback! I had originally done it as 3D because when the box-joint cutouts are carved, the interior corners will be round to the diameter of the tool. Nothing I can do about that. But the box-joint tab on its mate will be square since they are on the surface of the job board. When they are put together the joint will not fit right. The solution is to do it as a 3D model so that I can carve the box-joint tabs to have rounded surfaces to the same diameter. Seems like a simple solution, but the efficiency is terrible.

I've since modified my scripts to generate a 2D set of vectors to feed into VCarve. It is faster as you say (~ 1 hour), but I have to some manual sanding to make the box joints fix properly. So, it's a trade-off. Sure better than having to baby sit the machine for 4.5 hours
to make 4 sides of a box.

It would be a nice feature of VCarve to have a way to exclude certain portions of the 3D model from any carving. Sort of a "no fly zone". This would reduce the run-time considerably for cases like this.

Thanks again!

[Adrian]

I've since modified my scripts to generate a 2D set of vectors to feed into VCarve. It is faster as you say (~ 1 hour), but I have to some manual sanding to make the box joints fix properly. So, it's a trade-off. Sure better than having to baby sit the machine for 4.5 hours
to make 4 sides of a box.

It would be a nice feature of VCarve to have a way to exclude certain portions of the 3D model from any carving. Sort of a "no fly zone". This would reduce the run-time considerably for cases like this.

Thanks again!

The way round that with a 2D job is to use the dog bone fillet options on the inside corners so the square edge will fit in there.

VCarve does have the ability to exclude areas from cutting in 3D already. Draw vectors around the sections you want 3D machined and set the toolpath to the Selected Vector(s) options.

[tomgardiner]

How about a plunge round over bit to profile the appropriate edges.

[martin54]

the interior corners will be round to the diameter of the tool. Nothing I can do about that. But the box-joint tab on its mate will be square since they are on the surface of the job board.

That's what wood chisels are for
Only take a couple of mins to clear out rather than hours of extra carving. The CNC should really just be another tool in your shop, it's easy to get sucked in to doing everything on the CNC when you have one but often things are done quicker using other tools

[Rcnewcomb]

Or switch to a joint that can be cut on the CNC. 50 Digital Wood Joints by Jochen Gros

[martin54]

Or switch to a joint that can be cut on the CNC. 50 Digital Wood Joints by Jochen Gros

Jigsaw-Mitre-Joint.jpeg

Good post Randall, I've got that somewhere & forgot I had it

[sharkcutup]

Or switch to a joint that can be cut on the CNC. 50 Digital Wood Joints by Jochen Gros
Jigsaw-Mitre-Joint.jpeg

I have created a couple of these joints on my CNC Machine. They work very well!

Sharkcutup