Rest Machining How Does it Work in CC

I have the new feature in CC that is Rest Machining. I read about what rest machining is in other CAD applications. Basically it cleans up what a larger tool cannot get to in a tool path.

So my question is in CC when a tool path is generated and you check Rest Machining is another tool path generated to get what is missed by a larger tool. The dialog box asks for the previous diameter.

In my tool path I chose a 1" fly bit to pocket a rectangle.

The preview shows the left over corners shows this.

So is a tool path generated with the .25" from the rest machining dialog or how are the corners removed.

I’m not 100% sure but this looks a little like lazy “manual” rest machining and you have it backwards?

It looks like you might need to create a normal pocket with the larger bit (with no rest machining set). Then create the same pocket with the smaller tool and say “btw: this has already been pocketed by a 1” tool" in the “Rest Machining” part.

I much prefer Vectric VCarve’s approach where you give a pocket a bunch of different sized tools and it figures it out for you automatically and creates all the required paths.

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One has to start w/ a pocket w/ a large tool which removes everything but the corners:

That then gives one the dimension to enter for the tool which was previously used:

So that the preview is:

and if one zooms in, one can see the upper thickness of 0.0625" which is removed, and the corner of 0.0625" which the #201 wasn’t able to reach:

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So…the advantage of REST machining vs. creating an inside contour with a small bit to the same depth, is that the REST path will only cut the corners and “Quick” past the areas that don’t need cutting - whereas the contour will cut air?

Correct. That is the definition of Rest machining.

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Just to be clear in your example with enabling the Rest Machining you set the depth to 0.0625 instead of .125 in the original pocket just to show the part that was removed and what was left. On a real Rest Machining toolpath you would set .125 to match the larger tool depth.

Some of the other CAD programs I saw would automatically add a second tool path. In CC you create the original toolpath then create a second toolpath on the same object, check Rest Machining and the select a tool that is smaller than the original tool to get up into the corners and/or areas that the original toolpath could not reach.

My original tool path used a fly cutter that is 1" diameter. In the second tool path I selected a smaller tool and the simulation is a little wacked because the 1" tool likely not simulated properly but the Rest Machining is shown.

So do I have the concept right in my example.

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Yes, that all matches my understanding/experience.

In VCarve you specify multiple bits for a toolpath, check “rest machining”, and it will use them as appropriate to only remove what the previous bits have missed. For a rectangular pocket it should only hit the corners, of course for more complicated situations it will move around to the areas where the bigger bit wouldn’t fit. Pretty handy, and other than changing bits a lot faster, and avoids the hassle of trying to create additional toolpaths by hand.

What am I missing? I don’t see this new feature. I just updated to CC build 652 and don’t see an opti0on for REST anywhere. Is this for CC Pro? CC not-pro? Both? Where is it?

It’s in the pocket toolpath, and you have to have PRO turned on.

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@jac That’s the thing…it’s a Pro-Only feature.