Post processor and 5th axis issue

[vworpi]

I have an issue with one of my 5 axis post processors. I've attached a stripped down setup and a copy of my post processor.

The first drilled hole posts out correctly at A0. B65. The second hole is trying to post out at A180. B-65, which should be A180. B65.

I have a similar post for a B & C axis machine which works fine, but the job wont fit on that machine. I've got a feeling the issue lies within table:true/false in onOpen, but i cant seem to hit the magic combination.

Machine is a vertical, with an aftermarket rotary table.

[boopathi.sivakumar]

@vworpi 

Hi it seems the problem with the machine kinematics you set up in the post,

If it is trunnion table attachment then the table needs to be set true in both the axis. its all about where the rotary axis is present, Also i am suspecting the the rotary axis is faced perpendicular to Z and the prefix is"A"

here is the link https://forums.autodesk.com/t5/hsm-post-processor-forum/how-to-set-up-a-4-5-axis-machine-configurati...

where all the things about setting the kinematics right is well explained. if you have any problem over please let me know.

in that case i might need the machine kinematics details

[vworpi]

Yes the rotary axis is perpendicular to the Z. When I set both axis to true, I get the error flipped. The second hole is posted correctly, but the first hole tries to post to A180. B115.

Rotary axis is located on the right hand side of the bed, B0 is perpendicular to the Z axis, facing towards X-. B90 faces towards Z+.

Not how I would have commissioned it, but i think the previous owners did a lot of A axis wrap work.

[boopathi.sivakumar]

@vworpi 

As per what you have said the configuration should be something like this

  if (true) { // note: setup your machine here
    var aAxis = createAxis({coordinate:0, table:true, axis:[0, 0, -1], range:[-360, 360], preference:1});
	  var bAxis = createAxis({coordinate:1, table:false, axis:[0, -1, 0], range:[-10, 90], preference:1});
    machineConfiguration = new MachineConfiguration( bAxis,aAxis);

I am still not sure about the Baxis currently in the above code will set it as rotating along Y if you wanna change it to X then in the var bAxis change the axis to axis:[-1 , 0 , 0]

Also based on the setup you have given in the model it is not possible to tilt the b axis to -65 because it will hit the lmits either you have change the setup orientation within the limits something like this would work

[vworpi]

I'll give this a go over the next few days and see what works

[vworpi]

Sorry for the late reply, pandemic delays etc.

The post mod you suggested only works if B0 faces the Z axis, as shown in your image with the modified setup datum.

This machine is setup so B0 runs with the X axis, think like a 4th axis rotary table on a vertical machine. It's not something I can get around on this machine.

[vworpi]

I'm having real trouble with this one. It's been a proven post for over 12 months and it's now giving me problems with every new job I give it. The work isn't any different to before, simple prismatic machining, but I'm getting a lot of failed posts and a lot of "correct" posts with incorrect A & B values.

[vworpi]

@boopathi.sivakumar 

[boopathi.sivakumar]

@vworpi 

Sorry for the delay in reply do you have the old post with you ? which is giving the right values before.

also i am not sure about the machine kinematics do you have any pics of the machine ?

[vworpi]

I've reverted to a post from 2-3 months ago, with pretty much the same results.

B0 positionB90 position

[vworpi]

Again, this post is trying to generate a B-45 A180, rather than B45 A180.

I've also reverted to an older machine config, in case there's a conflict there.

[boopathi.sivakumar · Accepted solution]

@vworpi

your machine configuration should be something like this 

  if (true) { // note: setup your machine here

   var bAxis = createAxis({coordinate:1, table:true, axis:[0, -1, 0], range:[-10, 90], preference:1});
   var aAxis = createAxis({coordinate:0, table:true, axis:[1, 0, 0], range:[-360, 360], preference:1});
    machineConfiguration = new MachineConfiguration(bAxis, aAxis);

also you can setup as per your old setup this will post the correct values now

 

Check and let me know the feedback

[vworpi]

Looking good, I've had a few programs post out with the correct values now. It's probable that this post has never fully worked for me, but I've never actually had a job that hits that magic break everything point.

So it looks like a good chunk of my problem lay in having bAxis and aAxis reversed here:

machineConfiguration = new MachineConfiguration(bAxis, aAxis);

Thanks for the help.

[boopathi.sivakumar]

Yeah the the full rotary axis needs to be set second

[vworpi]

@boopathi.sivakumar 

I think we need one more small tweak to this. I changed the configuration to axis -1, as my A axis was reversed.

var aAxis = createAxis({coordinate:0, table:true, axis:[-1, 0, 0], range:[-360, 360], preference:1});

One of my operators has noticed some toolpaths are now generating g code with an initial X position with the incorrect sign.

M24

M11
M39
G54 G90 G00 A345. B0.
M10
M38

G54 G90 G00 X-5.075 Y0. S2653 M3    <-  I am wrong
G43 Z127. H9 T3
M7
G04 P3500
(SEQ - DRILL6)
G00 X5.075 Y0.     <- I am right
Z47.
G81 Z17.478 R29. F265.
G80
Z127.

 It doesn't seem to happen with everything, I have a few drilling toolpaths at A15. which generate correctly.

Reverting my A axis back doesn't fix it, just outputs in the wrong direction.

[vworpi]

@boopathi.sivakumar 

I'm definitely still not working correctly here. Attached are an f3d file and my current post processor.

If I run the OP20 setup through my post processor, it works, but my A axis positions are posted out reversed.

If I change

var aAxis = createAxis({coordinate:0, table:true, axis:[1, 0, 0], range:[-360, 360], preference:1});

to

var aAxis = createAxis({coordinate:0, table:true, axis:[-1, 0, 0], range:[-360, 360], preference:1});

to reverse the A axis, the post fails.