topic Re: engraving with medial axis pattern sometimes misses squares. in PowerMill Forum

engraving with medial axis pattern sometimes misses squares.

bfaberBB7MX — Wed, 10 Apr 2024 18:47:20 GMT

I have a macro written that uses a medial axis pattern to engrave parts automatically, but shapes such as periods that are squares will be removed about 50% of the time. Iv talked to our design department and got them to stretch their engraving text a bit to hopefully make all squares into rectangles but id still like to make my macro a bit more robust or at-least detect when it removes some of the engraving (maybe check if the tool path goes inside a boundary or something along those lines). Here is the code I use on a pattern that was inserted from the model based on a color selection.

EDIT PATTERN # CURVEEDITOR START CURVEEDITOR SELECT ALL CURVEEDITOR MODE OFFSET MODE TRANSFORM OFFSET DISTANCE ".0001" CURVEEDITOR FINISH ACCEPT FORM MEDIALAXIS EDIT PATTERN MEDIALAXIS ANGLE "155" EDIT PATTERN MEDIALAXIS CLEARANCE "0" EDIT PATTERN ; MEDIALAXIS APPLY FORM ACCEPT MEDIALAXIS

Re: engraving with medial axis pattern sometimes misses squares.

stdpattern — Thu, 11 Apr 2024 10:44:46 GMT

I can't help with your issue, sorry. Your engraving method sounds interesting though. I have always used a stick font and created patterns from that for engraving. Delcam Sans Serif is my go to font.

Can you point me to how your method works?

Re: engraving with medial axis pattern sometimes misses squares.

bfaberBB7MX — Thu, 11 Apr 2024 11:23:48 GMT

sure, my macro is pretty tuned to how we process parts but I can give you the backbone to how it works. You'll have to start with having your engraving color coded. I then create a pattern and insert all surfaces with that particular color

This gives you an outline of the engraving. You can then use this code to "shrink down" the lettering into a single line.

EDIT PATTERN # CURVEEDITOR START CURVEEDITOR SELECT ALL CURVEEDITOR MODE OFFSET MODE TRANSFORM OFFSET DISTANCE ".0001" //this will automatically fix the direction of curves to work with the medial axis command CURVEEDITOR FINISH ACCEPT FORM MEDIALAXIS EDIT PATTERN MEDIALAXIS ANGLE "155" EDIT PATTERN MEDIALAXIS CLEARANCE "0" EDIT PATTERN ; MEDIALAXIS APPLY FORM ACCEPT MEDIALAXIS

From there you can use a pattern finishing tool path to create the engraving. You might need to play with the axial offset and thickness to get the tool path flat.

Re: engraving with medial axis pattern sometimes misses squares.

stdpattern — Thu, 11 Apr 2024 13:10:41 GMT

Thanks, I'll look into this. Using the single line font works, but I have to tweak it nearly every time. Any font suggestions?

Re: engraving with medial axis pattern sometimes misses squares.

bfaberBB7MX — Thu, 11 Apr 2024 13:14:08 GMT

Theoretically any font will work but like with my original post any perfectly square or round characters are like a 50/50 chance they are missed.