Arc g02 in Kiri Moto

Kiri:Moto CAM
1

Hi everyone,
I’m very new to CNC milling and as you might imagine I have no idea what I’m doing.
This is what confuses me and this is what I did:

  1. I created 2D object in Inkscape (half circle image)
  2. Imported to Kiri:Moto
  3. Scaled the image X Y Z and got object I wanted
  4. I used Outline to cut out the same half circle object
  5. No g02 in the generated g-code
    Is this how it should be or Im missing something? It uses linear moves to cut-out arc.
    P.S I would like to say that I’m very impressed what Kiri:Moto can do (watched some tutorials online) . This is amazing piece of software. Thank you for creating it.
    Thanks in advance
    Bojan
2

when the 2D inkscape SVG is imported into KM, it becomes faceted as it gets turned into a 3D mesh / model. KM has code for FDM devices that “recovers” arcs from curves mesh surfaces, but this code has not yet been ported to the CNC mode.

3

Thank you very much for your reply. Very nice software. I hope this arc thing will be ported someday.

1 Like
4

Relative to CNC g codes : I have a 3 axis knee mill which uses a “fanuc like” g code format. I’ve historically used the pro E manufacturing workbench to generate code which creates g2 , g3 , and all the canned drilling cycles .

Questions follow:

1). Can you recommend closest post to use for this control ? Will this set up initialization g codes ?

  1. If I wanted to create a custom post for my control, is there a document that explains the details on how to do this ?

By the way, I am extremely impressed with what you have done with Kiri:Motto - thank you so much.

5

In CNC mode, KM isn’t outputting anything really complicated like arcs (yet). So if your controller supports G0 and G1, then pretty much everything else is driven by macros (header, footer)

6

So I guess I would have to achieve curved shapes using tight tolerance with linear motion ?

By the way, do you have a collection of model files which you consider to be test / verification cases to test Kiri:Moto CNC functionality ? I’d be happy to machine these with my milling center using the “fanuc like” from wax (maybe aluminum) if that helps you with validating codes. And I’m sure other issues may come up that may be of concern to you related to code development.

Let me know if you are interested.

7

since KM can’t support nurbs or other curved geometries natively, to achieve tighter tolerances, the STL/OBJ exports just need much denser faceting. in FDM mode, I have code that detects arcs (not splines) from a series of points and has the option of outputting arc gcodes in those cases. it’s on my TODO list to port this to CAM. but it’s only going to be as good as the interpretation from points.

thanks for the offer. I really need to create an automated test suite. and I’ve had false starts toward this in the past. given that the project is really just me, I’m limited by time and other realities. if you’re offering to collaborate to create such a set, that would be amazing.