I think I've found a bug in the NFS wizard "Cut Circle"
I'm trying to use it to clean up the ouside diameter of a 1" thick round plate.

I set the following into the cut circle NFS wizard.
Material Aluminum = +1
Max spindle speed 1450
max feed rate 20
inches
select the cut circle wizard
surface speed for special tool 0.0
tool #1
tool diamter .250
HSS tool
number of cutting tips 4
chip load per tooth .0017
inches
spindle direction CW
Flood
overides - spindle 100% Feed 100%
Percent plunge 20
speed and feed calculates to 1450 and 9.6
X center 0 - Y Center 0
Circle diameter 5.483Groove
Outside
CCW (conventional mill)
Pitch 0.5
Depth 1.02
Rapid Height 0.1
Step Depth 0.01

If I look at the preview IN THE WIZARD I see what I would expect, which is the tool approaching the material from the outside and spiriling down to the full depth of 1.2 inches while milling on the outside diameter of the plate - Good!

If you post the code and look at the toolpath display in MACH,  the tool is following some stange path. It starts above the plate, spiraling down and out to the proper diameter. The path downward apparently meets the plate at a point of the proper diameter just as the tool touches the plate. It continues around the plate at the proper diameter so theoretically it should work but if the tool height does not start exactly right the tool will meet the plate too soon.

Good thing I checked the code with foam.

Can someone figure out what I'm (or the program) is doing wrong. I have a job I need to get out the door by the end of the weekend and sorry to say I'm not experienced in G-code enough to write the program properly by hand.

PS> I used the wizard to create a similar program using a 1/2" hogging mill to rough out the initial diameter. That tool path looks ok when posted so I'm not sure why the particular parameters I listed above do not work.

Thanks

Sage

Further to above, I've discovered that if I change the diameter to 5.493 instead of 5.483 that small difference makes the MACH posted code show properly.

Can anyone figure out why?

 Still confused as to what is going on. The manual says that a G02 may change its path depending on tool offsets and such but it makes no sense to move from inside to outside when it's an ouside path specified.



Sage

Which version are you running? It should be 2.79

There was a bug in the tool comp code that shwed this effect- it was different between the POST and the PREVIEW buttons.

V2.79 is in another topic on this forum

Thanks I'll give it a try.

Sage