G2/G3 Arc Paths options

[bubbasnow]

would be nice for the people who have the option to 3d print using regular gcode

[jimc]

Funny, s3d had this a long time ago and it was removed

[JFettig]

Consider that there are no arcs in the input file, the STL file is made up of polygons, slice them and you have a bunch of small straight lines. Yes it would be cool, the g-code would be much smaller and lower data rate of running a file.

[jimc]

are you sure about the data rate thing? i thought it was removed because the atmega processors couldnt handle the calculations fast enough to control the printer smoothly. i could be wrong of course but i seem to remember something about that.

[JFettig]

Generally in the real CNC world(mills, lathes, etc), the output G2/G3 arc path options are enabled to create smaller files and the look-ahead in the code is usually 10-100 line(making this number up). One single arc can be comprised of hundreds of lines of code thus creating a bigger file.

So in a sense, lines of code per second would be greatly reduced - Sounds like some printer hardware isn't capable of computing simple positional moves based on arcs though

[jimc]

on almost all printers the processors are so limited we are at 100% max capability with no room to grow. the firmwares are completely maxed for what will even fit on the the boards. unfortunately there is nothing i know of on the horizon.

[JFettig]

Smoothieboards are supposed to be quite a bit faster than typical printer boards, then you have beaglebone black boards and machinekit which can basically do anything you can dream of. But for your typical consumer grade printer, you're pretty much right.

[bubbasnow]

Yup im using a beaglebone black with a bebopr++ running machinekit/linuxcnc. i can fully utilize the g2/g3 codes

[Cosineadditive]

We would LOVE to see this implemented. Currently we're going through a huge amount of hassle to recreate arcs in a post processed gcode. The smoothie firmware has been updated to handle G2/G3. The physical quality difference it makes is amazing, especially on large machines. This is the single biggest problem we see in slicing currently.

See here for some comparison pictures.

http://www.cosineadditive.com/blog/2015 ... d-printing

[Alex Borro]

Even the regular boards based on AtMega are capable of performing arc movements. One just need to adjust the segment resolution.

Check the videos bellow:

https://www.youtube.com/watch?v=vgukgdK ... gFCS7PqFu3

This CoreXY is running a Rumba Board with Marlin.

I have asked the S3D support to provide a G2/G3 "Experimental" checkbox so the user can activate it.

It is a feature that just add benefits.

Cheers.

Alex.