I have a keel profile drawing that I have extruded from a curve.

Curve looks great, but when I generate the 3d tool path it does not follow the curve and draws large flats that are 'away from the part' on one direction and then gets closer when generating in the other direction.

I am going to try to attach cad drawing with part of the tool path generated.

Original part drawing is hidden in yellow, cleaned up with spline is in blue hidden, extruded part is visable in green and tool path is in blue.

How can I get the tool path to follow the contour of the part? The flat's in the part can be both seen easily.

Thanks in advance.

Sam

Well I figured it out all by my self. Thanks for not answering real fast..... Even a blind hog will find an acorn every once in a while. (I mean no offense to any blind hog's out there, I admire your persistance.)

The 3d tool path in above file was generated by the Planer Path at a 90 degree angle to the part. Never used that before, will help in the future a lot.

I changed the tool path to 90 degrees to run up and down the foil and it generated a reduced line count file. Over 100,000 lines to under 2,300 lines.

When I tried spiral, code followed part very well. Odd that planar didn't.

Any thoughts?

Sam

I don't have V21 here at home to try it. Sorry I can't help. I did use v21 for some time though and never had an issue running at different angles.

I was surprised that it would follow the curve in spiral but not in planar. But I learned that you could change the angle of the code which fixed it for me.... Good to learn something new that shoulc save me some time.

For a finish cut, is astep over of 10% of the router bit a good place to start? I am using bits with a round tip not ball ends.

Thanks

Sam

For finish cuts it will require more opinion than anything. It really counts on the finish needed as well as the surface complexity. Also how much handwork it will require when done.

The tool will make a huge difference on the step over required but also the surface form dictates the tool needed. Small fine detail may require a pointed tool but a flat surface would be easier with a flat tool. The stepover distance between the two is no comparison.

I'm working in mdf with a 1/4" bit.

I thought a small amount of sanding would be required. But with the flats, it would take quite a bit of work.

I am going to change the tool path to cut the length of the part instead of the previous passes.

Will post better picture after the next final pass.

Sam

I think the problem you are having is mostly due to the surface your created or the settings you are using for the tool path.

When BobCAD v21 cuts a surface it does it with all line movements. In order to get a smoother path you need to adjust the amount of line movements it creates for the arc / surface you are trying to cut.


In the tool path option you can adjust the angle of cut step over, also the tolerance and minimum line length.

By adjusting these settings you be able to cut the shape smooth with out the flats you had mentions.

If you are not able to cut the surface smooth with out the flats, then you need to go back and look at how the surface was created. It might be a problem with the geometry at that point.

In the tool path option you can adjust the angle of cut step over, also the tolerance and minimum line length.

Allen thanks for the input.

On my finish pass, I used step over of 1 mm, toolpath angle of 0, tolerance of .0001 and minimum line length of .0013 which is the minimum allowed by the software.

This is close but still has definite planes instead of a smooth curve.

I guess the code generater for "spiral out or in" is way more percise than the planar generator. Go figure....

The 90 degree toolpath angle will get me what I need.

Sam