Machinist threatening to quit over Fusion 360 CAM bug.

[peteGCAB6]

Hi all,

We design in Fusion and our in house machine shop makes our parts. There is a bug that occurs sometime between the CAD and CAM environments that is so frequent and so frustrating, it is causing major issues with one our machinists, who is so wound up and annoyed about it, that he is threatening to leave us. 

This relates to holes and surfaces quite often not being perfectly perpendicular to the face. This is so small, it does not even register when using the inspect tool to measure. If a hole is 0.000001 degree out of square, the drill, bore and threadmill operations will not generate a tool path to cut. 

I dunno how this happens, as all features are obviously referenced off existing faces, nothing is intentionally drawn at a very very slight angle. 

The solution is to use 'selected point' instead of face, and then use heights to control depth, but this only works for point operations like drilling and tapping. 

For thread milling and boring, the solution is to create a sketch on the plane that was used as the z reference during setup, then draw a tube and extrude it through the problematic hole, then select that to drive the toolpath from. 

This can also cause problems during cad, for example measuring distance between two planes will often just result in an answer of 0.0deg, rather than a distance, and this can also stop the horizontal tool path from picking the surface up, as its not perfectly parallel. 

The problem clearly originates during the design phase, when a hole is made (either extruded from a sketch or using the hole tool) it is being created very slightly at an angle to the surface it is meant to be perpendicular to. This problem then follows the file to the cam environment where it rears its ugly head and causes so many problems. 

This is causing problems for him on a daily basis, and it's driving us all mental, and I sympathise entirely with him as it is very frustrating and a long winded solution to resolve.

Could someone from Autodesk please acknowledge this and let me know if this is known about and when we can expect this to be resolved?

[jeff.pek]

It would be great if you could share a model that is showing this behavior, so that we can take a look.

Thanks,

  Jeff

[peteGCAB6]

Hi Jeff,

Happy to send files over and show you the problem. Can I email them to you? Can't really post them publicly on here as they are real components from our product line. 

Also happy to show you the problem on screenshare over zoom or similar. 

Pete, 

[seth.madore]

If I may suggest an alternative workaround, better than sketches and added model features:

use Tool orientation. There is an issue on the Model side where holes are ever so slightly out of alignment, to the tune of .0000002 degrees or some rediculously small value. I've got a followup discussion planned with the Model team on that front....

[peteGCAB6]

Hi Seth,

The problem with using tool orientation is Fusion will post out A and C moves, which the machine has no axis to control, which mens it will just error out when the control sees an A or C value and there is nothing there for it to move (have seen this before) 

This also does not really address the problem very elegantly, as we have this problem frequently where there are multiple holes on the same plane and face, which we would like to bore or thredmill together. Half the holes work, the half dont, so using tool orientation would mean each hole would need to have its own operation with its own orientation, which is hardly practical. 

I have got the latest part up on my screen and have confirmed I can reliably see the problem happening, so I can send you this if it helps to demonstrate the issue. 

Thanks,

Pete. 

[jeff.pek]

As Seth suggests, we have made a change for an upcoming update, which will hopefully improve this. Having a model that we could test with would still be helpful.

You can e-mail to me at jeff DOT pek AT autodesk DOT com.

Thanks!

  Jeff

[peteGCAB6]

Hi Jeff, 

I have sent you an email.

Thanks,

Pete,.