G02 & G03 in MDI

what's the formula to find the cut radius. i'm trying to cut a
1/4" radius with a 3/16" end mill. with a 1/4" end mill, i know it's 1/8" radius for i and j.


this is my start
g17 g20 g40 g49 g54 g80 g90 g94 g92.1



Thanks
kenneth

drawing it in cad i get .156" but i would still like the formula
as i still don't know if this is right.


Thanks
kenneth

piasdom wrote:

drawing it in cad i get .156" but i would still like the formula
as i still don't know if this is right.


Thanks
kenneth

That doesn't sound right. 1/4" is .250 diameter
3/16" end mill is .1875"
So, the 3/16" end mill needs to orbit the difference between these
sizes, which is .0625" diameter. The radius of that would be
.03125"

The way to think about it is the hole is .250" diameter.
The tool radius is .09375", and the tool center needs to
approach each side of the hole leaving a clearance of its
radius. So, simply, hole diameter - tool diameter is the
diameter of the toolpath circle.

Jon

thanks jmelson, but if i use that formula;
1/2" hole using 1/4" endmill = 1/2"(.5) - 1/4(.25) = 1/4"(.25) radius
i cut a lot of 1/4"(.5 hole) radii and i always use 1/8"(.125) radius to get 1/4" radius.
(below is example)
so if i sue that formula for 3/16"
1/2"(.5) - 3/16"(.1875) = 5/16"(.3125) radius.
unless i don't understand the formula (been known to happen:)


g1 x.04 y-.165
g2 x.165 y-.04 i.125
g1 x3.565
g2 x3.69 y-.165 j-.125
g1 y-.275
g2 x3.565 y-.4 i-.125
g1 x.165
g2 x.04 y-.275 j.125

Thanks
kenneth