[Danno]

First time machining a part, and for some odd reason only one contour machined smaller, whereas everything else machined right on size.

The 2 1/2" diameter hole came out .080 smaller (2.420")
I have no clue if it's a glitch in the post processor or something I did.
The .DXF drawing was done with OnShape, and the G-code generated with Dolphin CAD/CAM ( my first time using the CAM part)

I've enclosed the original drawing, as well as the first lines of the .TAP file because the 2 1/2" hole is the first to be cut ( I couldn't post the whole program)

Edit; I notice it's difficult to see the writing in the second picture, but line 25 looks like this;

N25X-1.085I-1.0075J0.0

I'm no G-code expert, but to me, that " X-1.085 " seems to be the issue. ( 2 times 1.085 plust my .250" diameter cutter equals 4.20 )
Shouldn't that be X-1.125" ??

Thanks for any help.
Dan

[andre-dolphin]

Hello Dan,

I think this is something to do with an approach move or arc splitting.

Please send an email to [email protected] and attach the .cnc please and I'll take a look.

Regards
Andre

[Danno]

Thank-you Andre !