[cdntoolmaker]

Hello everyone,

I was wondering if anyone out there can tell me how to write a program that would turn a 3/4" dia. ball on the end of a shaft? Are there any wizards or macros to help with the programing? Any help would be greatly appreciated.

Thanks,
cdntoolmaker

[uperez]

Hi! It's easy if you're using a round insert. Just simply add the radius of the part and the radius of the tool in your R value in the program. You just have to calculate the starting point in z if you're starting the arc from the shaft side, or the end point in z if you're starting the arc from the ball end side since your shaft diameter must already be given then the X value is already known.

PS: this is if you are not using tool nose radius compensation (G41/G42).

[cdntoolmaker]

Hi uperez,

Thank you for your responce. I don't think I stated my question properly. I'm looking for instructions on how to write the actual code. I am new to programing and I have been using Mach3 and Lazycam to generate my 2 1/2D code for milling applications. This is my first try at Lathe cnc. My sizes are on the end of a 0.3125 dia. x 1.500 long shaft there would be a 0.750 dia. ball. So once again any help would be greatly appreciated.

Thanks,
cdntoolmaker

[dcoupar]

I'm confused. How do you get a 0.750 diameter ball on the end of a 0.3125 diameter shaft? Can you post a picture of what you want?

[cdntoolmaker]

Hi dcoupar,

You ask. "How do you get a 0.750 diameter ball on the end of a 0.3125 diameter shaft?"

I could do it two ways.

1) Thread one end of a 0.3125 dia. x 1.500 shaft and screw a 0.75 dia. x 0.75 blank on the end and then turn the ball.
2) Start with a 0.75 or 0.875 dia x 2.25 long blank. Face and turn one end to 0.3125 x 1.5 long. Then mount the 0.3125 end in the cnc lathe and turn the ball.

For turning the ball end I would be using a 0.094 wide top notch carbide insert with a full radius on the tip. The cnc lathe it would be turned on is the size of a sherline so I would not be able to hog off the rough cuts. Maybe roughing passes of 0.020 and finishing passes of 0.005. I believe the control is very similar to the Fanuc G&M codes because it needs a % sign at the beginning and end of the program.

Once again, any help would be greatly appreciated. Thanks.

[MDU]

Hi! It's easy if you're using a round insert. Just simply add the radius of the part and the radius of the tool in your R value in the program. You just have to calculate the starting point in z if you're starting the arc from the shaft side, or the end point in z if you're starting the arc from the ball end side since your shaft diameter must already be given then the X value is already known.

PS: this is if you are not using tool nose radius compensation (G41/G42).

How do you set up the tool and what will be the T and R value on your geometry offsets?

[LeeWay]

I did some programming by hand to start with for my first cnc lathe.
It was just some basic stepped bushings, but allowed me to get into Gcode quite a bit.

What I did initially was produced some code using Sheetcam for my mill.
I took that code, broke it down, switched the axis letters and tried it out.

I saw results immediately.
Then I added code like peck drilling and some other routines.
That helped me become familiar with it.

I soon became aware that to do much more than the basics, I would need a good turn cam. I chose Dolphin. I had lots of excellent help from Hood on the Mach 3 site to get the Post Processor to spit out precisely what I needed for my lathe. Set up the tool tables etc in Mach.

Now for any profile, all I need to do is draw half the profile in CAD and run it through Dolphin. Even though it is that easy, learning to code it by hand is a very useful skill. You can glance at the code and tell exactly what should be happening on the machine.

I never had much luck with the Wizards in Mach or in turn, but the code it spit out was also helpful in the learning experience.

[chucker]

Here is a finish pass for a 3/4 ball this should give some Idea of what you need tool nose is allready figured in.
%
O0000
(35 DEG. INSERT - VNMG-431)
G0T0101
G97S3600M3
G0G54X0.Z.15
G50S3600
G96S200
G99%
G1Z.05F.01
Z-.0003
G3X.5584Z-.1344R.3906
X.7489Z-.3702R.3906
X.75Z-.3906R.3906
X.4813Z-.6854R.3906
G1X.312Z-.759
Z-1.
X.4534Z-.9293
G28U0.W0.M05
T0100
M30
%

[Bob Adams]

I did some programming by hand to start with for my first cnc lathe.
It was just some basic stepped bushings, but allowed me to get into Gcode quite a bit.

What I did initially was produced some code using Sheetcam for my mill.
I took that code, broke it down, switched the axis letters and tried it out.

I saw results immediately.
Then I added code like peck drilling and some other routines.
That helped me become familiar with it.

I soon became aware that to do much more than the basics, I would need a good turn cam. I chose Dolphin. I had lots of excellent help from Hood on the Mach 3 site to get the Post Processor to spit out precisely what I needed for my lathe. Set up the tool tables etc in Mach.

Now for any profile, all I need to do is draw half the profile in CAD and run it through Dolphin. Even though it is that easy, learning to code it by hand is a very useful skill. You can glance at the code and tell exactly what should be happening on the machine.

I never had much luck with the Wizards in Mach or in turn, but the code it spit out was also helpful in the learning experience.

This is how i do it with CAD2Lathe. Zip file has Mach3Turn Gcode and DXF file. Demo at:
Free programs

[Bob Adams]

This is how i do it with CAD2Lathe. Zip file has Mach3Turn Gcode and DXF file. Demo at:
Free programs

Mach 3 Turn config.
Gcode is for the Front tool post with Arc's reversed.

[MetalZilla]

Does your machine need I and K for the circular interpolation or can you use an R value?