Spiral operations

Recently had to cut a 3" diameter hex pocket, which I started by cutting a round pocket.

Have a 1" diameter end mill, which I had intended to use, but it turned out to be completely dull, but I wanted to do this cut in steel, rather than in butter.

So had to revert to using a 3/8" diameter end mill, and cutting 5 concentric circles, using G2 and G3.

However, reading the docs for G2 and G3 lead me to believe that there was a way to cut a spiral using a single line of G code. Seems to work well for a helical move, why not for a spiral move.

Any thoughts?

G2/3 only cut arcs on the chosen plain and as you know can extend those arcs to a spiral by the addition of Z.

I think the only way to cut a spiral on the chosen plain is with G5.2/5.3 nurbs.

John

I ended up using a ngcgui sub for this.

Rick G

There is a spiral.ngc in the example files that shows how to do a spiral.

John

BigJohnT wrote: There is a spiral.ngc in the example files that shows how to do a spiral.

John

Thanks

I'll look for that.

Tom