[Heirloomwindows]

Greetings,

I need to write code parametrically for "Arch Top" window sash. There are numerous arced paths involved (CutOut OD, Plane on center line, Rough Cutout ID, Profile ID) but they are all arcs of concentric circles so the circles centers are all at exactly the same point XY.. The length of the part is on the Y axis. The center line of the part is on the circle diameter and all share the same Y coordinate with the diameter.

It's easy to calculate the X coordinates at this center diameter - for example the finished part is 2.125" wide so the OD is at X 0 and the ID is at X 2.125. Using a 1/4" bit the OD path would be through X -.125 and the ID path would be through X 2.25. The problem lies in what the X coordinates are at the ends of the arcs since they are not at that point diameter and are significantly different than those at the diameter. For example, at the ends of the same part that's 30" long the difference between the OD and ID of the finished part is 2.227".

I'm sure I could scrounge around and find the trig algorithm to specify the X coordinates at the ends of the arcs but I'm hoping there is a G-code function that allows me to specify the center of the circles, the length of the radii and the start and end Ys. One would think that's all the information needed to execute the path.

See attachment for simplified image.

Thanks

[joeavaerage]

Hi,
yes you can specify the center in at least one mode of Gcode arcs....but are you planning to write the Gcode by hand? Old school...laborious....error prone?

Why not use a CAM program like Fusion 360?

Craig

[Heirloomwindows]

Hi,
yes you can specify the center in at least one mode of Gcode arcs....but are you planning to write the Gcode by hand? Old school...laborious....error prone?

Why not use a CAM program like Fusion 360?

Craig

I have Fusion and V-Carve but I'm making this programmatic/parametric. I'll write algorithms in excel with the specs on one page, calcs on another then code that references the calcs on another page. That way, next time (and there will be many) all I have to do is input the part width, length and one radius and it will generate the code for me. I have my whole window making operation setup like this. So, please share the structure of the code with me. Again, I'm hoping to just specify the circle center XY, the radius length and the start and end Y.

Thanks

[joeavaerage]

HI,
the two modes of specifying a circular arc are quite well known and widespread< these were take from the Mach4 G Code programming manual, but are repeated in any number
of publications.

Craig

[marynorris]

At least one Gcode arc mode can be used to set the center. Will you, however, be writing the Gcode by hand? Traditional... exhaustive... prone to mistakes?