3D Adaptive Clearing milling fillets which are already good on stock model

[jas.okon]

Hello there,

I have a small problem with getting my stocks working as I would like to.

I have played a bit with Fusion and I encountered this problem:

In my job, we usually regenerate or change machine parts, and we get drawings of input and desired part of the machine from a client.

I hope that if I make (or import) a model of stock and my desired model and set them appropriately within setup setting there will be no machining of faces without any changes.

Yet adaptive clearing insists on machining most of round shapes in the model like fillets, balls, spheres etc.

I believe that problem might be connected to that fact models were at some point imported from the Inventor, or maybe that's just a quirk of how the stock model is being resolved. Is there any way to fight with it ?

I'm attaching example part so you can see my problem with adaptive. It should only machine middle of the part, as outer fillets are unchanged compared to the stock model.

Kind regards,

Jan Okoń

[ivan.stanojevic]

Hello,
Have you tried using the bounding box option instead of "none"?

Tool containment should be at least set to be on boundary center.

[Steinwerks]

Yes you've hit on one of the stock conversion issues. As the solid body is converted into an STL for background computation it will produce triangulation fragments, especially where radiused edges are concerned. You already have the answer in your part though: use the large rectangular sketches as boundaries and set your Machining Boundary to Tool Inside Boundary with a decent Additional Offset to let the tool ramp in somewhat. This was set that way with the Additional Offset at 5mm:

[jas.okon]

Yes, it's acceptable workaround in most of the situations but sometimes its
hard to draw suitable one. However it doesnt answer the question why is
fusion even bothering with mashining those features.

[Steinwerks]

I just told you, when the stock model is converted into an STL it has triangular fragments it sees as not matching the finished model (or at least that's my best theory and I don't think I'm wrong), so it machines them away. Unfortunately I am not aware of any way to increase the resolution of the stock model.

@fonsecr can you apply any insight here? I'd also like to know if I'm correct (or whether I am not)

[jas.okon]

So there is no differences between stock model draw in fusion or imported - they are both converted to stl ? 

I guess the other posibility is to get rid of the fillets from both stock and model if they are not to be machined.

[fonsecr]

I'll check it tomorrow.

Adaptive Clearing might machining stock on steep walls. You can to some degree reduce this using the Rest Material Adjustment setting under Rest Machining. But this is a feature we need to improve on.

Once I had a look I can confirm.

[fonsecr · Accepted solution]

The issue here is not the quality of the rest material here since you have modeled the stock as a solid.

You do not use stock to leave for your toolpath which is normally not good since Adaptive Clearing is a roughing strategy would not leave a nice finish. Not using stock to leave will also make if more difficult for the kernel to avoid unwanted cutting of stock - since stock to leave influences the criteria we use to figure out when to cut the some given stock.

That said we already have on our todo to improve rest material handling for Adaptive Clearing. But I have opened a ticket for your particular example CAM-6748 also.

[jas.okon]

Thanks for the answer. It clears things up for me. I guess I'll play with stock to leave and then with some finishing pass. 

Shame that adaptive clearing doesn't have touch surface as in most of the finishing operations it's the way I deal with the problem - I allow only important surfaces to be machined

What does opening a ticket means? You mean for your internal bug tracker ? Can I follow it somehow?

[fonsecr]

Tickets are for us to track features/improvements/bugs. We dont expose the tickets externally but we often reference them in releases or on the forum.

[jas.okon]

I have found a good workaround for this problem, so I post this so other may use it, or even Autodesk team can incorporate some of this into the standard routine for stock creation.

If you have two solids: one for a model and one for stock, which differs in only some parts, and when using one for the stock you get a lot of passes around round corners then you can do following:

1.) use create->boundary fill with those two solids.Then you want to choose all parts besides your model solid. It will create separate bodies for each area which differs between model and stock solid (which hopefully are the only area you want to machine, or you have done something wrong with those models.)

2.) Go to CAM-> Setup, pick your model solid as the model, and all of those bodies we created earlier as stock. DON'T pick your original stock model as a stock.

3.) Turn off visibility of created bodies (this might require you to go back to model environment or even to file with your models if inserted them from another design, a bit annoying - I know)

4.) Create your tool paths as usually - Now it works as supposed to work, no more machining nonexistent stock. You might be surprised how good it is. For me, there is no need to input ANY machining boundary and  I still get perfect toolpath for my 3D adaptive clearing.

5.) The only flaw is where you go to the simulation of the tool paths. You must have your model solid visible otherwise you will see only excessive material flying around in the air. Also, you need to turn off the visibility of those created bodies otherwise will block the vision of your machined stock.

For me, it works like a charm I hope you'll find it useful as well. 

Is there any chance that some of this might get incorporated into the logic behind using solids as a stock? I guess most of the people using solids as models have problems same as me (as long as the have any circular shapes )