I have an extruder attached to my cnc router. I've never had much luck with G64. The default settings always round off sharp corners. I usually use G64 P0.1, which doesn't make much difference to the speed.
I managed to get the Douglas-Peucker algorithm working. It shaved 4 minutes off a 20 minute print, which was good considering there wasn't a lot of arcs (the part was a thick washer - round outside with a round hole, but filled with horizontal and vertical lines). With a tight tolerance, it's more of an arc fitting algorithm. Performance is the reason I wanted to the arcs fitted. It's annoying watching the machine move at 2400mm/min in straight lines, then slowing down to 400 going around curves which I know are part of a circle. But, as you say, my fundamental issue is losing the curve information when I convert my CAD models to STL. This will go into the "too hard basket" for now - the waterline processing sounds interesting, but I'm put off by having to process a CAD file. Thanks, Frank -----Original Message----- From: Kent A. Reed [mailto:kentallanr...@gmail.com] Sent: Friday, 29 March 2013 12:52 AM To: Enhanced Machine Controller (EMC) Subject: Re: [Emc-users] convert g1s to g2/3s On 3/28/2013 7:56 AM, BRIAN GLACKIN wrote: > G64 does this for you without changing the code. > > > See > http://www.linuxcnc.org/docs/html/gcode/gcode.html#sec:G64 > > for more details. > On Wed, Mar 27, 2013 at 6:17 PM, Frank Tkalcevic < > fr...@franksworkshop.com.au> wrote: > >> >Does anyone know of a script that converts G1 line segments into >> >G2/G3 curves? In the src tree I found author.py which has an >> >implementation of the Douglas-Peucker simplification algorithm, but >> >I can't see where it is used. Is there a script anywhere that uses it? >> > Frank: If you are after speed rather than fidelity, then Brian's answer is spot on. Let's be clear though that both G64 and the Douglas-Peucker algorithm are just smoothing filters. They neither know nor care that your original curves are composed of circular-arc segments. If it's important to you to preserve their circular-arc character then you need to use a toolpath generator that works from your original 3D model rather than the triangulated surface model that was extracted from the model and transferred to Slic3r via an STL file. I seem to recall the subject of recreating circular arcs from line segments has been discussed on this list in the past but I don't recall any magic solutions being offered. I'm intrigued by the juxtaposition of the words "Slic3r" and "router". Are you using Slic3r to create 2D contours that you cut with a CNC router or are you using a CNC router with an extruder as a 3D printer? If the former, then you may want to look at so-called waterline milling algorithms used in CAD/CAM to see if you can generate more efficient toolpaths. Our very own Anders Wallin has opined on the subject (http://www.anderswallin.net/category/cnc/cam/waterline-cam/). Regards, Kent ---------------------------------------------------------------------------- -- Own the Future-Intel® Level Up Game Demo Contest 2013 Rise to greatness in Intel's independent game demo contest. Compete for recognition, cash, and the chance to get your game on Steam. $5K grand prize plus 10 genre and skill prizes. Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Own the Future-Intel(R) Level Up Game Demo Contest 2013 Rise to greatness in Intel's independent game demo contest. Compete for recognition, cash, and the chance to get your game on Steam. $5K grand prize plus 10 genre and skill prizes. Submit your demo by 6/6/13. http://altfarm.mediaplex.com/ad/ck/12124-176961-30367-2 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
