# Thread: 2D Pocketing a rectangle but want to leave an INNER rectangle Out of the routine-How?

1. ## 2D Pocketing a rectangle but want to leave an INNER rectangle Out of the routine-How?

I have a shape that I want to cut only the gray area (not the inner rectangle). Is there a good way to do this?

Also, I'd like to have sharp corners on the gray rectangle's outer edge but I'm using a 1/2" spiral. What's the best way to accomplish this? I know there will be outset .250" radius cuts outside of the rectangle in each corner. That's ok, but I'm not sure how to accomplish this.

The objective is to be able to put a sharp cornered insert into the gray area. So the outset .250" in each corner is ok. I just need to know how to do it.

So I guess that's two questions:
1. How to only cut the gray area rectangle and leave out the white.
and
2. How to allow for a sharp cornered mating part to fit into the gray area (how do I avoid radiused corners that'll prevent the mating sharp cornered part fitment)?

2. offset your geometry half the cutter diameter and don't use cutter comp.

3. Originally Posted by ssoptical
offset your geometry half the cutter diameter and don't use cutter comp.
Won't that just make a bigger rectangle?

by the way I got it figured out. I just select both the inner and outer rectangle as my geometry.

But I still haven't figured out how to have sharp inner corners on the outside edge of that gray rectangle.

4. In order to put a square corner in there you are going to have to relieve the corners. To do this you are going to have to run the end mill to the corner and then out at a 45 de gangle to just past the edge of the part. It is going to have radius' out side of the gray area if that is eceptable then that is the baest way to program that. If that is no good then you are going to have to machine the corner as small as you can and then broach the corner square

Good luck!
Jim

5. The easiest and most common way I have seen/used to "relieve" a corner is to simply drill holes, one at each corner and then just run the pocket, only thing to watch is that it is usually best to run an end mill that has a slightly smaller diameter than the drill used.

Here is how the attached Bobcad file looks in BC and after the simulation in Predator Editor 2.

Regards
Rob

P.S. Done in V23 Build 1812

6. Originally Posted by The Engine Guy
The easiest and most common way I have seen/used to "relieve" a corner is to simply drill holes, one at each corner and then just run the pocket, only thing to watch is that it is usually best to run an end mill that has a slightly smaller diameter than the drill used.

Here is how the attached Bobcad file looks in BC and after the simulation in Predator Editor 2.

Regards
Rob

P.S. Done in V23 Build 1812

I dont think there is that option in pocketing ,but you can use the Loop options of Corner type in Profile edit.
You can use that profile option after pocketing to get rid of the curved corner made by any round cutter.

bisect line would work as well.