Strange 2D Contour problem

[micr0]

I have a chain that consists of 8 entities (lines and arcs)that i want to contour with a 1/2" EM. However when I select the geometry and generate a 2D contour tool path it looks as if mastercam failed to use all of the geometry and I get only a partial tool path. If I Analyze>Chain the report tells me that I have 8 entities (which is correct). If I go to the tool path geometry and right click on the chain and select analyze it tells me that there are only 4 entities in the chain. I selected the geometry by using the select chain option not window select and the whole chain seems to select fine and looks as I would expect (FWIW I did try using window select to see if it solved the problem and it didn't). I have checked for gaps an didn't find any. I checked for extra geometry and din't find any either. If I change the start point sometimes I get some weird toolpaths. I have even tried redrawing some of the lines and arcs as well as checking my C and T plains. I'm really at a loss can some one please help.

 

thanks

[cobra95kev]

Can you post a screen grab of the shape of the geo?

Check the infinite look ahead switch on the operation parameters page. Toggle it and regen and see if it is right. Also on lead in lead out page check the gouge check button and try it again?

Thats all I got.

[taperlength]

I get that sometimes and just trim each entity to the entities next to it and then it works ok.

Analyze chain seems to be less picky than toolpath chaining.

[Justin Beebe at Folsom Tool]

Is all of your geometry created at the same Z-depth? If it's an ID contour can your tool fit into all areas of the contour. Have you tried to run the find overlap c-hook? You can also see where the entities in your chain begin and end by selecting screen/display entiy endpoints. You can select partial chain, check the box that says "wait", and select each entity individualy.

 

HTH

[Thad]

Do you have "shorten" checked in your lead in/out settings?

 

Thad

[micr0]

Thanks guys. Shortly after I posted the question I noticed the the contour tool path was defaulting to a 3D contour. I squashed all the geometry to the XY plane and made sure that the tool path was 2D. I also went around the chain and trimmed all the entities to each other and that solved the problem. How the geometry may of wound up outside of the Cplane is a mystery.