# Thread: Having trouble with 3d on V24

1. ## Having trouble with 3d on V24

Hopefully I can explain my problem without to much confusion. I am having trouble getting a 3d path to work. I am working from a raw forging I have a angle i need cut on one side of the part. I am able to get the angle programmed, my problem is that the top surface of the part is not to be machined, and my 3d cutter path is cutting into the top of my part. I posted a zip of the bbcd file. If anyone can help i would greatly appreciate it.

thank you

2. Looks like you have the "tool center" programmed in the feature? If you use tool tip, then it will look like it stops. If you need tool center, then you may want to offset your boundry by that cutters half.

Also, for your boundry, it looks like you have "drawn it" to try and be close to where you want it to stop. You can get a more exact boundry by extracting the edges of the surface/s you are cutting, then create a flat plane up above Z0 and then project those edges up to the flat plane. An exact boundry.

3. Burrman, I have tried with tool tip and tool center. As far as I can tell I get the exact same cuts. I did think about offsetting the boundary, my question on that is. Would I have to offset half of the cutter or would I have to do the math for where the angles would meet the radius of the cutter

4. Here is a file back.. I re-created a boundry and also selected the entire solid as geometry then used the boundry to constrain it...

Is this cutting how you want?

5. Thanks that is much better on the boundary. It is still digging the center into the forging. I changed the boundary colors to help describe what I am needing. the part of the boundary that is yellow is not machined. the yellow portion of the forging will actually be higher than it is on the 3d model. I need the cutter path to stay away from the top of this area. I am just getting started with bobcad. How did you create the plane above to project the boundary to.

6. So in this screenshot, the toolpath is constrained down below the surface of the yellow area, but you want it to be constrained in the "z direction" also, like the red arrow here?

How did you create the plane above to project the boundary to.
On the surfaces menu, look for rectangular plane or circular plane. The planar command will create a plane from a planar, closed loop.

7. Yes that is pretty much what I want. If you run verify the way it was programmed you can see where the cutter is digging in to the area of the part that is uncut. You can hopefully see that in the pic I am going to upload. The program is good other than the one area.

8. OIC. You have not done any roughing and the tooling would hit material up there. What you can do is put material there on the model, the the system will know a 3/4 inch tool needs to avoid it... You can make a copy of your object on another layer, then use "extrude surface" for that area, then boolean union the parts together, then select that as the geometry.. Here is a screengrab of an exagerated extrude, maybe not so high so you are cutting less air.

I changed the lace angle to 22.5 which was a better fit? Although, I think I still got one little anomoly in the backplot. May have to play with the settings/setup and stuff to eliminate that...

You did mention offsetting the boundry, and that may be the more appropriate way to go, but I dont know enough about machining/tooling to suggest anything on how/why... It may be a better solution to avoid the air time that this method creates.

9. That is exactly what I am looking for right there.