Need Help!- Mastercam reversing half of my chains

[Bfarn]

Hi All,
I've got a vector file here with lots of tiny little areas to cut out - four thousand actually. I'm making a contour toolpath, and there's more than I can chain by just picking them one by one, so I'm chaining using Window mode. It works fine at finding all of the chains, but it sets some of them to clockwise and some of them to counterclockwise. This means that when it's calculating the cutter compensation, half of them cut on the inside and half on the outside - which is not cool.

Some quick technical stuff:
-Software is Mastercam X4
-All of the chains are closed chains, so they SHOULD be consistent
-The vector art came from an Adobe Illustrator autotrace - so it's very detailed, but I don't have direct control over the order that points were laid down or anything (though that shouldn't matter, right?)
-There's thousands of shapes, but they're all really simple. Most of them are just rectangles or ovals.

So are there just too many chains for mastercam to handle? Am I making some basic mistake? Something else? Hopefully it's just a quick fix or a button I don't know about...

Thanks

[Limpan]

Hi, do you want to cut the whole area inside every closed chain or do you just want to follow the contours? What kind of tool did you select?

[Bfarn]

Originally Posted by Limpan Hi, do you want to cut the whole area inside every closed chain or do you just want to follow the contours? What kind of tool did you select?

I'm just trying to follow the contours. I'm trying to cut out all the little holes and then lift the finished piece, leaving a bunch of small shapes behind on the table.

I'm using a 16th inch flat end mill, which is too big for some of the smaller details - but I'm ok losing a few of them. If a shape is too small, it just kicks back an error (Cutter Compensation Failed), and moves on.

Maybe if I was doing pockets instead of contours it would be able to detect the inside vs the outside better - but that's a huge waste of cutting time, when just cutting out the shapes clean and leaving them behind would do the trick.

[zone023]

Hi,

Had a similar problem a while ago with open contours.

It was caused by duplicate entities.

So maybe "Delete Duplicates" will help...

[Bfarn]

Duplicates! You know, I bet that's it. That would account for some other weirdness I've been running into as well.

Thanks a bunch!

[zone023]

Duplicates can cause some weird behaviour...

There should be an automatic warning in Mastercam if it detects dupliacates.
Can save you some annoying hours...

I hope it solves your problem.

[Limpan]

If you set the cutter compensation type to "OFF", the center of the tool will follow the contours, perhaps you're okay with that?

[Superman]

Window selecting is a quick method, attachment is snapshot of my config.
but pay attention to your settings in the "Nested Chains" and "Direction of closed chains" area. You may have "reverse inner chains ON".

If you select the shapes using smaller windows, taking less shapes each time, then your toolpath will not jump around too much, it would machine your windowed areas completely in the order you boxed or "polygoned" those areas

[Bfarn]

Everybody, thanks for the advice. I ended up just using a pocket toolpath, which was able to detect my shapes well enough despite the lousy vector data. But even with the job cut, I'm gonna go back into the file and check out what could have been causing the trouble.

I really appreciate the help you guys have given me, hope to return the favor.