Wanting Gcode for an arc lathe

I don't have any cam for a lathe but could anybody help with some gcode to produce an arc.

the chord length is 150mm and the radius is 1407mm which is about 2mm at the centre of the chord. I need to make a small crown on a 150mm wide pulley.

gnipsel.com/files/linuxcnc/gcode/

The l is lathe and the m is mill ie different planes and XZ vs XY.

JT

BigJohnT wrote: gnipsel.com/files/linuxcnc/gcode/

The l is lathe and the m is mill ie different planes and XZ vs XY.

JT

Thanks for the quick reply how do you use the arc generator with the axis display

Looks like I needed to zip the files first.

gnipsel.com/files/linuxcnc/gcode/arcgenl18.py.zip

open the file in Axis and a Send to Axis button appears.

Edit: I probably need to add a G18 to the lathe one...

JT

BigJohnT wrote: open the file in Axis and a Send to Axis button appears.
Edit: I probably need to add a G18 to the lathe one...
JT

I have played with it in Axis but not sure how to use it. My goal is to create a crown on a roller 150mm wide I calculated that the chord length would be (same as roller) 150mm and the diam. of he circle to get 2mm crown would be 1407mm.

I am not sure how to plug the numbers in starting at Z0
X centre Arc 2
Z centre Arc -75
dia. of Arc 1407
Start angle 90
end angle 270
Direction CW

Where am I going wrong?

Could you please give me a hint. Thanks

Clive s wrote:

BigJohnT wrote: open the file in Axis and a Send to Axis button appears.
Edit: I probably need to add a G18 to the lathe one...
JT

I have played with it in Axis but not sure how to use it. My goal is to create a crown on a roller 150mm wide I calculated that the chord length would be (same as roller) 150mm and the diam. of he circle to get 2mm crown would be 1407mm.

I am not sure how to plug the numbers in starting at Z0
X centre Arc 2
Z centre Arc -75
dia. of Arc 1407
Start angle 90
end angle 270
Direction CW

Where am I going wrong?

Could you please give me a hint. Thanks

Your math is wrong, you have calculated the approximate radius of the arc. Next the degrees are not 180 but they are 6.11 degrees included so the correct entries would be
2
-75
2814.5
3.06
356.94
CW

I see another problem with the program you can't select units... so you can't run inch on machines set up for mm and the same on machines set up for mm you can't run inch.

Edit: I'm not a math wiz, I cheated and used SolidWorks to lay it out and get the angles...

JT

I updated the wizard to include units and fixed a couple of things.

If someone is going to use this I need to port the Tk over to GTK3...

JT

JT
You have given me a light bulb moment re the start and end angle I was giving it the full 180 degrees. Instead of the angles from the centre of the circle to each end of the chord. I did that in autocad so I cheated as well

I had a typo above I calculated the radius as 1407. I said diam in stead of radius.
Not sure what you mean with the units. If I have G21 set I enter the units in MM I also have G18 set.

I will test this out in the morning

I do appreciate your help. Thanks

ps can this also be done without the ( I) peram using X Z R

OK I have tried again with:-
2
-75
2814.5
3.06
356.94
CW
It is giving me X values of about 48 which can't be right.

After reading your last post#79879 I re downloaded it but I don't see any changes. Is the wizard only set up for inches as I am using metric.