How would you do an oval?

[alank2]

Hi,

I've been playing around with the G02 command using emc2 sim mode, but I don't see a way to do an oval. How would you make an oval?

Thanks,

Alan

[ger21]

Do you mean an ellipse?
An oval is two half circles with straight lines between them. Two G2's and two G1's.

[alank2]

Hi Gerry,

Do you mean an ellipse?
An oval is two half circles with straight lines between them. Two G2's and two G1's.

Yes, I'm sorry, an ellipse - how would it be done?

Thanks,

Alan

[txcncman]

You can either simulate an ellipse with multiple arcs or you can write a macro that will calculate the elliptical points down to the resolution of your machine. Either way, you need to be fairly knowledgeable and practiced on your math skills.

[ger21]

I draw it in AutoCAD with arcs and create the code from that.

[angelw]

Hi Gerry,



Yes, I'm sorry, an ellipse - how would it be done?

Thanks,

Alan

Hi Alan,
Here's an example of how to machine an ellipse using User Macro. The resolution of the ellipse is achieved via variable #4.

Regards,
Bill

%
O0021
N1 G00 G17 G21 G40 G80
G91 G28 Z0.0
G28 Y0.0
T01 M06
S1000 M03
G90 G54
#1=100 (X RADIUS)
#2=50 (Y RADIUS)
#3=0 (START ANGLE)
#4=50 (NUM OF POINTS)
#5=360/#4(ANGLE INCREMENT)
#6=0 (COUNTER)
#24=#1*COS[#3]
#25=#2*SIN[#3]
G00 X#24 Y#25
G43 Z10.000 H01
G01 Z1.000 F1000.0
G01 Z-5.000 F100.0
#6=#6+1
#3=#3+#5
WHILE [#6 LE [#4] ] DO1
#24=#1*COS[#3]
#25=#2*SIN[#3]
G01 X#24 Y#25 F300.0
#6=#6+1
#3=#3+#5
END1
G00 Z10.000
G91 G28 Z0.0
G28 Y0.0
M30
%

[alank2]

Hi,

Thanks everyone!! I'll try out that code Bill!

Alan

[neilw20]

As long as the long axis is X or Y, you can change the scaling on 1 axis, then just program a circle.
Easy in MAch3. Not sure about emc2 though. Never used it. Never wanted to. Probably never will.

[samco]

here is an example written for linuxcnc.

LinuxCNC Documentation Wiki: Oword

I have not tried it...

sam

[angelw]

Hi,

Thanks everyone!! I'll try out that code Bill!

Alan

Hi Alan,
The Macro Language used in my example is for a Fanuc or Yasnac control, but the logic and math is the same irrespective of the control.

Regards,

Bill

[sinha_nsit]

I draw it in AutoCAD with arcs and create the code from that.

Let us say major/minor diameters and angle of major dia with x-axis is given.
What do you do next?

[FuddMcDee]

Hi Alan,
Here's an example of how to machine an ellipse using User Macro. The resolution of the ellipse is achieved via variable #4.

Regards,
Bill

%
O0021
N1 G00 G17 G21 G40 G80....
%

Thanks a ton for this, I mean really, a ton. It's useful little goodies like this that make me ok(ish) with not using software to write programming. I came up with a hole boring sub with variables like the program you have here, and I was far happier than I imagine I would've been had the code just gotten thrown at me.