Choppy Code / Surface Finish on Arcs

[pete.oxenham]

Having issues with surface finish on non-constant radius arcs. Machining strategy is 2d Contour.

Distance between points is .029 regardless of these settings. Will alternate between G1 and G2, although we can force G1 for everything and the problem persists. How do I fix this?

Have tried changing the following:

Smoothing (Off, .0001 - .0004)

Minimum cord length (.25-.005)

Minimum Circular radius (.01 - 200, idea being to eliminate G2 moves entirely)

Problem persists in both Haas EC and Fanuc post. For the record, machine smoothing is turned on however the problem shows whether or not we have smoothing on, since it is an actual issue with the code.

Any help is greatly appreciated!

[seth.madore · Accepted solution]

Can you share your part? If it's an ellipse or spline, smoothing doesn't do squat for it. Known bug, no estimate on when it will be resolved, unfortunately

To share the part: File > Export > Save to local folder. Return to thread and attach the .f3d file in your reply

[pete.oxenham]

Thanks for the reply Seth,

It is indeed a spline. I can't share the file, and given that this is a known bug I think we wouldn't have much to gain from that regardless. 

Is there any workaround? I'd really hate to have to switch our cam package entirely due to to this problem.

[seth.madore]

3D Contour works well with splines, you can use that instead. It won't give you cutter comp, but a heck of a lot smoother ride.

@HughesTooling refresh my memory, but that's pretty much all we can do with splines and arc fitting, right?

[pete.oxenham]

Thanks for all your help Seth. I was able to generate what appears to be usable code with that strategy. I really appreciate your effort.

One critique, and this is not meant to be taken harshly. I think the Fusion team should revisit their priorities, as they're wildly misaligned with the actual needs of industry users. I'm constantly seeing updates (good updates abeit, from a technical standpoint) to features that are of little use to anyone other than the youtube/hobby-shop/prototype community (which I understand is your core market), while basic functions such as contouring splines and replacing model references are left entirely neglected.

I appreciate the Fusion team's mission of pushing forward new features, but a lot of broken or missing basic-level features are completely left alone - if just a bit more development effort were diverted back into getting the basics solid, Fusion 360 would be far more competitive with Mastercam etc.

Again, thanks for all your work on this. Excited to see future updates.

[seth.madore]

Hey, preaching to the choir, man. I'm in your shoes on a daily basis, as I use Fusion to run my shop (day job). 

I'd REALLY love it if you could privately share your part. One more part I can toss at them and say "See, another customer needs this fixed"

If you can, email it to me: seth dot madore at autodesk dot com

Heck, I don't care if you redact a bunch of features and leave just the base profile. Something to work with...

[pete.oxenham]

Sounds good Seth, I'll send the file over right now.

[Anonymous]

@seth.madore ,

You've got another one in your mailbox from me. Having the exact same problem this morning, turned to the forums for help, and top of the list was this thread. Timing.

David

[HughesTooling]

The problem with 2d profile is when the offset is generated the corners are rounded by the radius of the cutter(Corner Rounding), good thing when the toolpath change by 90°. Really they should arc fit before doing the offset or have a tolerance setting for corner rounding of 5°.

You will find smoothing will work on 2d profile if you set the offset to in control and use G41/42 by the way.

Mark

[HughesTooling]

---

@pete.oxenham wrote:

One critique, and this is not meant to be taken harshly. I think the Fusion team should revisit their priorities, as they're wildly misaligned with the actual needs of industry users. I'm constantly seeing updates (good updates abeit, from a technical standpoint) to features that are of little use to anyone other than the youtube/hobby-shop/prototype community (which I understand is your core market), while basic functions such as contouring splines and replacing model references are left entirely neglected.

I appreciate the Fusion team's mission of pushing forward new features, but a lot of broken or missing basic-level features are completely left alone - if just a bit more development effort were diverted back into getting the basics solid, Fusion 360 would be far more competitive with Mastercam etc.

Again, thanks for all your work on this. Excited to see future updates.

---

Don't forget the CAM team and the CAD team are not the same for Fusion, so what I guess you see as improvements for the hobby\prototype market are not affecting CAM updates. 

HSM started out for mould and die work and the 2d stuff was only for basic stuff so I think the core market for CAM is still more towards 3d machining than 2d. For mould making rectangular pockets and bosses are all that's needed, all the rest is 3d and the big money coming into HSM is still going to be from Mould and Die.

Mark

[Anonymous]

This is my problem part:

The radius on top is 2500mm. No matter what I try, no arc motion is output, just G1 moves about 6mm long. With or without smoothing.

I run this lying down and 2d contour around it. I always use "in control" for finishing like this. Tried 3d contour too, with no success.

Post is Generic Mitsubishi.

David

David

[HughesTooling]

Can you export and attach the design as an f3d and attach. Some posts have a max radius setting and for 3d you'd need a very tight tolerance before it'll convert to arcs. 

Mark

[Anonymous]

Nope, no can do. 😞

I sent it to Seth this morning, we'll see what he has to say about it.

Of course I could send it to you too. 🙂

Regarding 3d and tolerances, I tried 0.005 and smoothing 0.01. You mean REALLY tight?

David

[seth.madore]

@Anonymous  your issue is actually post related. Your radius is 2500mm and I'd wager a decent amount that your post is set to a max rad of 1000mm. It will linearize anything over that. Yes, there are reasons for that; some controls that ADSK have encountered were not able to process arcs over that amount, so they set the cap (globally) to 1000

You can change this quickly in the post dialog:

[Anonymous]

Yup, that was it.

Banging my head over here... Second time in two weeks that the solution was so close. 🙂

Salutations from a springlike Skellefteå at latitude 64.

David

[pete.oxenham]

Any update on when the team plans to have this fixed?

Pete

[seth.madore]

Regarding splines and ellipses, there is no news to share. The solution for this is a lot deeper than just toggling something in the backend.

Current solution is to use 3D contour, unfortunately.

[pete.oxenham]

Thanks Seth,

Is the team actively looking for a solution, or is this on the back burner? I'm not trying to be a PITA, just want to know whether to hold my breath or not.

Pete

[seth.madore]

The (proper) solution to this is going to require a significant amount of work on the backend, I would not be holding my breath...   😞