Fusion Lathe CAM Question?

[Anonymous]

I am testing a simple lathe part using a grooving operation. the stock diameter is 0.5 and the finish diameter is .48".

in all the posts I have tried, the output shows all radial positions exactly double the correct dimension. the part finish pass should be radius .24", but it is .48". The clearance position where the program starts should be at .65" radius, but it is at 1.3" radius from the z axis.

I have checked the part repeatedly, and it is .24 radius, .48 diameter. with the program it will come out .96" diameter.

Nothing in fusion 360  shows anything incorrect, but all 5 lathe posts do the same thing.

Any ideas?

[GeorgeRoberts · Accepted solution]

Hello,

Thanks for posting. I assume this is caused by the post processors outputting in diameter mode, rather than radius mode. You can change to radius mode by editing the scale value in this line of your post processor:

var xFormat = createFormat({decimals:(unit == MM ? 3 : 4), forceDecimal:true, scale:2}); // diameter mode

To be this:

var xFormat = createFormat({decimals:(unit == MM ? 3 : 4), forceDecimal:true, scale:1}); // radius mode

Hope this helps!

Edit: You might also need to change some of the startup codes, what post processor are you using?

[Anonymous]

Thanks George.

Perfect answer, that fixes it.

I am still experimenting with different posts. I have a planet CNC 4 axis controller on a home built CNC lather/mill.

looks like the Fanuc code is accepted by my controller without complaint now that it is fixed.

What is the purpose of diameter mode in a lathe?  seems like radius is the right way to go but all 6 posts I looked at were using diameter mode.

Brian