Originally Posted by
ERUS
Yes. If you run it on the machine you can see the C axis turning as its engraving. X stays at 5" diameter through the whole run. I didn't think it would by just looking at the code, but it did.
Using G112, when there is a Y move in the program it converts it to a C move. When the machine is at X0. the wedge will only allow the Y to move +\-2.0". By using G112 Cartesian to polar transformation it converts the X&Y moves into X&C moves this allows you to machine around 5" diameter part even though the travel is only +\- 2.0" in Y. The machine itself is doing the math when you use G112. But it is less accurate than if you just used the X&Y as you would on a regular cnc. With G112 the tolerance is about +\- 0.001" at a 5" diameter. It get worse as the diameter grows from 5" because the resolution for the C-axis just isn't there.
I modified a 3X mill post to swap the X and Z axes. I don't know what software you are using but the geometry for the D wasn't flat it was curved on a 5" cylinder, and I used a 3D contour toolpath to follow the curve. I could not get it to work if it output the code as G2 or G3 arc with I,J,or K. It has to be line segments.
If you tell me what text you want, character size, and the diameter of the cylinder its going on I can post some code?