Bug in CAM Pattern Mirror

[marc.a.grossman]

I came across what I believe to be a bug, or at least an oversight in the CAM mirror feature.

Basically, I often use my cnc mill to cut out sheet metal parts which I then bend. Most of my work in done in/on aluminum. Aluminum should always be climb cut assuming a low backlash machine, which a CNC mill is given it's ballscrews. When I mirrored a toolpath, I got the original that was a climb cut, but the mirror was a conventional. I think this a bug. The screencast shows the issue.

[brianrepp]

Hi @marc.a.grossman - I don't see a screencast, do you mind trying to post again?

[marc.a.grossman]

My mistake. I thought I had attached the screencast. Oh, now I see I think I had tried to attach it, but clicked post before confirming the insertion of the screencast.

[Matthew-R · Accepted solution]

@marc.a.grossman 

Thanks for sharing this with us. I've investigated this with our development team and they do know about this behavior. It is logged with them as CAM-1717. So, it is something that they are aware of, but there isn't a timeline that I can provide which would include this feature.

You mentioned using a Linear Pattern and in addition to that, another work around would be to use a Circular pattern of two instances about an axis that would serve as your mirror parameter.

Another option for the time being could be to duplicate the toolpaths that are to be patterned, and use the compare/edit feature to make them all be conventional cutting. Then put them into a mirror pattern and turn off “keep original”. All resulting operations will be climb cut because they are mirrored from a conventional toolpath.

I hope this info helps and let us know if you have any other questions. Thanks again and we really appreciate the comments in the Screencast and your continued support of Fusion 360!

Matt

[marc.a.grossman]

It's definitely not a high priority item. As you mentioned there are plenty of work-arounds. I was only pointing it out so that you knew about it.

Love fusion360 and so glad to be windows/solidworks free. Keep up the good work.

-Marc

[Farzati.Scott]

I am experiencing the same issue with using the mirror pattern.  When can a resolution be expected?  I see a ticket was created...

[Farzati.Scott]

When can a resolution to the mirror function in CAM be expected?  A ticket was issued in February and several people have had this issue.  I too am coming across this bug in using Fusion.  This program is utilized for more than fancy models and renderings.  These parts many times go to production and CAM needs to be working solid on expensive CNC machines with modern tooling....

[Matthew-R]

@Farzati.Scott

Thanks for posting to this thread. I've reached out again to the development team asking for an update on this issue. I hope to receive news from them within the next couple of days and I'll be sure to provide an update here. Thanks again for your patience.

Matt Reineck

Technical Support Specialist, CAM

[Matthew-R]

@marc.a.grossman @Farzati.Scott

I received news back from the development team and this issue has been described as more of a feature request that a defect report. Currently though, this change cannot be simply implemented. It doesn't fit into the way that patterns are handled. I would suggest voting for this feature request on the idea station by following this link:

Mirrored Pattern with Proper Milling directions and Entries

In short, this isn't an easy fix. It is being considered as a feature enhancement for the future though.

Please let me know if you have any other questions and I would be happy to have them addressed.

Best regards,

Matt Reineck

Autodesk HSM Support

[Farzati.Scott]

Then I would suggest that this so called feature be removed. Cannot have a
tool running in the opposite direction if you want to mirror the toolpath
on the opposite side of the part. Vari-flute carbide coated endmills are
meant for climb cutting and aren't inexpensive throw away items. We
aren't back in the stone age any longer...

Once again the focus is solely for the design of parts by Engineers and not
the more important factor of being able to manufacture and put into real
world production of them. Have come across multiple features as you
mention that have been discussed for years without any results.
Disappointing!

[Anonymous]

It seems as though they could easily automate one of the "workarounds" create an option that will first change all of the toolpaths to conventional before mirroring. This is a major issue, I can't think of a single part we make that doesn't have a mirrored version. The Compare and Edit doesnt even allow me to change all of the toolpaths to conventional, you have to go and do them all one by one. Not convenient at all.

[FrodoLoggins]

"this issue has been described as more of a feature request that a defect"

No, this is clearly a defect...

[seth.madore]

No, no it's not a defect. It's simply a mirror of everything, including the direction in which a tool goes

[FrodoLoggins]

Which no one would ever want to do...

[marc.a.grossman]

Except that when you're an actual machinist you know there are times when
you want to climb cut and times when you want to conventional mill. The
mirror as-is is not a feature. It is definitely a bug... ask any machinist.

[seth.madore]

Ahem...

I am an actual machinist 😉

A software bug is when something occurs other than what was intended. This actually IS intended, as it's just a low resolution implementation of a mirror toolpath. Quick and dirty...

[andy.concept303]

Just come across this same issue which is still yet to be addressed.  Mirroring the tool path for handed parts was quite a useful feature I thought, until I discovered the climb vs conventional issue.

[rhdfmail]

The workaround is also "stupid" If I have to dupicate  say, 25 operations and then edit them to conventional before mirroring I can just dupicate and reselect the geometries/toolorientation for them as I program them OR Mirror them and then change direction on the mirrored ops