G-code radial arc blending

[BeezCNC22]

Hello..i was looking for some help in creating the programming codes to produce a R12.7 internal arc that continues into a R19.05 external arc with a 1" endmill? Simple coding i'm sure but we don't do much of this at our shop....usually just a simple mill, drill and tap application.

[MMMMM]

Originally Posted by BeezCNC22

Hello..i was looking for some help in creating the programming codes to produce a R12.7 internal arc that continues into a R19.05 external arc with a 1" endmill? Simple coding i'm sure but we don't do much of this at our shop....usually just a simple mill, drill and tap application.

It sounds easy enough however, you're missing some basic information.
From what dimension to what dimension? What kind of control? Do you plan on using cutter comp? Which cutter direction? Are these arcs 90degrees each?

For a basic Fanuc assuming no comp;
G01G42D1XxxYyy
G02XxxYyyR12.7(interpretted as no move)
G03XxxYyyR19.05
G01Xxx

Now, for without comp and assuming that you'll need I,K centers;
G01XxxYyy
G01XxxYyy(arc cannot be same as tool)
G03XxxYyyI-6.35J0
G01XxxYyy

Whenever you're programming arcs, you need to write the ARC ENDPOINT. How it gets there (via radial move) depends on either the Radius (R) created or the Center of the Radius (Ix,Ky) from the starting point.

Now, just to make this even more confusing, SOME machines require ABSOLUTE arc center designations. It really depends on which control and what parameters are set.

[BeezCNC22]

to produce an S-curve. first arc is internal at R19.05 with arc center at X 213mm, Y 73mm.......2nd arc that it blends into is an external R12.7 with arc center at X209.3mm, Y40.5mm......and i am using a 1" diameter endmill. The coding will just be G-code M-code on a Mazak Fusion 640M control......

[BeezCNC22]

There will also be no cutter comp used....prefer I and J being on a Mill

[angelw]

Originally Posted by BeezCNC22

to produce an S-curve. first arc is internal at R19.05 with arc center at X 213mm, Y 73mm.......2nd arc that it blends into is an external R12.7 with arc center at X209.3mm, Y40.5mm......and i am using a 1" diameter endmill. The coding will just be G-code M-code on a Mazak Fusion 640M control......

To help you with an example, you still have not supplied enough information. You don't say where on the R19.05 radius you want to start and where on the R12.7 you wish to finish. There is another issue:
1. If you refer to the attached drawing, you will see that arcs generated from the centres and radii listed in your Post will not intersect.


D= Diagonal distance between arc centres
D=Sqr((213-209.3)^2 + (73-40.5)^2)
D= 32.7099

D1=The sum of the radii of the two arcs
D1=19.05 + 12.7
D1=31.75

Gap = D-D1
Gap = 0.9599

There is a gap of 0.9599 between the circumferences of the two circles. Therefore, a program where one arc blends with another arc directly, based on the data supplied, is not possible.

Accordingly, I suggest that you Post a sketch or detailed drawing of what you wish to achieve.

Regards,

Bill

[MMMMM]

As you can see from Bill's reply, we need more information.

ASSUMING that your trying to figure out the tangent line between the two, here is the code w/o comp - to match the picture attached;



(start at) X206.65
G01 X206.65 Y73.0
G03 X210.786 Y67.049 I6.35J0
G01 X218.158 Y64.305
G02 X234.7 Y40.5 I-8.858 J-23.805
G01 Yyy

[angelw]

Hi Doug,

Looks like the OP's gone Missing In Action.

Regards,

Bill