Edge Chatter 2

[frogwood]

I posted last week about what I called edge chatter on a 2D profile cut. Thanks to everyone who made suggestions. I 2D probed a Victorian style baluster and then spent several hours going back zoomed in close adjusting nodes slightly to get perfect curved vectors. Maybe I over worked it? Once I got the one like I wanted it I copied and so I could cut 3 at a time.

When I got to cutting wood I had edge chatter. One of my problems was that I was using an aggressive bit. I went back to using a straight double flute bit. I still got an edge that was not as clean as I thought it should be. Gary in my first post said that probe interpretations aren't always perfect. Maybe that is the answer and what I am asking you guys about? Do you get real clean edges on 2D probed files?

I went back and designed a part with similar curves using the curve drawing tool in PW. When I cut this piece in a few types of wood it was cleaner with only minor machine marks like you might see on a straight blade planer.
I also went back and cut the file from the probe again and cut it out of trupan. Again in this file I had 3 identical parts. When I stacked the parts on top of each other the imperfect edge marks echo each other on each piece. So it does not seem to be chatter but something going on with the probe file.

In the same part that I have problems with there is a circle that was created using the circle draw tool in artworks. There are also some straight edges that just have a node at the corners. On the circle and the straight portions the edges are all clean. Maybe because there isn't a node every .1"

It's leading me to believe that with the probed file you are not going to get
the clean edge as you would if you used the drawing tools in PW and created the part? Is that your experience? Am I overlooking something?
I have numerous patterns for parts that I wanted to probe and clean up thinking it would be easier than drawing everything from scratch. But it
I can't expect to get a better edge than what I have gotten so far I suppose
everything will need to be designed in artworks?

[srwtlc]

Allen,

Your probed file is most likely (almost guaranteed) made up of many straight segments, each one being a small straight movement at the machine, which will yield a faceted, chatter appearing type of cut.

In PartWorks, you can select the vector and chose the "Fit curves to selected vectors" tool which will help to smooth out the profile. You'll have to try various settings to get the desired results and you may still have to do some node editing to further refine the profile. It won't do a node count reduction though so you'll still have a lot of nodes to deal with.

If you have a copy of CorelDraw, you can do some node reduction in there.

[Brady Watson]

All profiles generated from the probe need cleanup. In fact, I don't ever use the original curves from the probe. Instead, I import it and then proceed to trace over it with the polyline tool. Just rough out the shape with straight lines, noting where you would want a node for curves etc. Then come back in Node Editing mode and add in bezier curves and extra nodes as necessary to fair the shape to the original. It really isn't hard, and it really doesn't take that long. If you want professional results, this is the only way to go. There's no 'Easy Button' on this sort of thing. The upside is you'll hone your drawing skills, which will easily pay you back in the long term.

-B

[frogwood]

Thanks for your advice. I looked in the tools in the version of PW I have and did not see
a choice of "fit curves to selected vectors" I think the version I have is 2 and there is a 3 now. Do you know if that is a new feature added to version 3?