Milling a Helical on a Tube

[m.salisburyPTB97]

I am attempting to Mill a helical slot in a tube. the 3D model and simulation show the endmill tracing the slot perfectly fine and aligned on centerline.  I had some issue getting the post processor to generate the program because it does require the 4th axis (A) for the Tormach 1100 that I am using.  I edited the false to true on the appropriate line and when I load the program to the machine, it has the mill cutting an inch off on the Y axis and Z does a weird taper isntead of remaining constant through the entire cut.  The Tube is aligned along the X axis with the slot running along the top of the tube.  The simulated tool path, using wrap, looks beautiful on fusion, but there is something getting messed up once it goes to the G code.  The code shows it being off on Y axis, so the machine is properly doing what it is told. Any help?

[m.salisburyPTB97]

Attaching a picture of the simulation

[engineguy]

@m.salisburyPTB97 

Which Post Processor are you using, can upload a copy of your modified and your Fusion f3d file ??

[m.salisburyPTB97]

I got the tormach.cps file from the site, and it says it should be ready to post 4 and 5 axis movement but I was still getting the failure to generate error due to multi axis output.  It wasnt till I went in and changed the false to true, that I have in bold below

} else {
if (true) { // note: setup your machine here
var aAxis = createAxis({coordinate:0, table:true, axis:[1, 0, 0], range:[-120, 120], preference:1, tcp:useTCP});
var cAxis = createAxis({coordinate:2, table:true, axis:[0, 0, 1], range:[-360, 360], preference:0, tcp:useTCP});
machineConfiguration = new MachineConfiguration(aAxis, cAxis);

[engineguy · Accepted solution]

@m.salisburyPTB97 

As you don`t need the C Axis you can comment that out and reset the MachineConfiguration as below, not required but just removes any C Axis outputs.

} else {
if (true) { // note: setup your machine here
var aAxis = createAxis({coordinate:0, table:true, axis:[1, 0, 0], range:[-120, 120], preference:1, tcp:useTCP});
// var cAxis = createAxis({coordinate:2, table:true, axis:[0, 0, 1], range:[-360, 360], preference:0, tcp:useTCP});
machineConfiguration = new MachineConfiguration(aAxis);

Possible that you need to change your WCS to the center line of your A Axis so that the toolpath rotates around the center of your A Axis ??

Have you selected the correct "Rotary Table Axis" ??

[m.salisburyPTB97]

I selected X as the Rotary table axis, should it be Y?

[engineguy]

@m.salisburyPTB97 

🙂 No idea, I can`t see your machine, how do you have the 4th axis actually fixed ti the table ??

[m.salisburyPTB97]

It is a 3 jaw chuck on a rotary table, so it has the end of the tube in it, rotating around centerline of the tube.  The tube is layed out lengthwise on the X axis

[engineguy]

@m.salisburyPTB97 

Then it is rotating around the X axis, so that would be correct.

[matty.fuller · Accepted solution]

Often for a rotary/4th axis you also need to ensure the YZ origin is on the axis of rotation, looks like this might not be the case in your setup.

[m.salisburyPTB97]

You two were correct. I needed to change the WCS to the center of the rotation axis for A. It worked fine once I did that