Anyone Ever Use Pencil Mill Before Finishing?

[Reko]

I have an operator that says he worked in a mold shop that used a pencil type toolpath to finish smaller radii in corners first... then the finish ball end mill would not chatter in the corners, and it would leave a better finish.

 

I was thinking about trying it, but when I backplot it, pencil mill BEFORE the finish ball EM, because it is a small end mill, it looks like the first pass would be taking a pretty big swipe along drafted walls.

 

I've never tried it... just wondering if any of you mold shop programmers make a practice of this or have ever tried it?

[specv]

I have done this on parts (like the one in my sig) and it left a better finish in the corners, the tool does engage a little more stock so i did leave stock and did a clean up pass only taking a few thou.

[Teh Bear without Brains kinda idiot]

I did it lots of times mostly when my tools were extra long

[K2csq7]

+10000, but I use 2d contour (ramp), convert 3 to 5 if I need shank clearance. 

[mikenaturalice]

I used to do this all the time. it will take more stock, depending, but I would do like specv and leave a bit-o-stock and then come back and do a 'finish' pass. Funny now that I think of that because the work I do now I rarely ever have to finish like that just because the work is different... Weird how at one time that was my 'go to' surfacing op/procedure and now that I think of it have not done that in years. Not that I found a different way, just the parts I do are different. 

[Micromoldmaker]

If this is the high speed "pencil" tool path, you can adjust the amount taken with "Limit  # of offsets to."  You can plug in values so your tool doesn't cut all the stock at once.