topic Re: Serious CAM simulation shortcoming? in Fusion Manufacture Forum

Serious CAM simulation shortcoming?

garmitage — Tue, 19 Dec 2017 18:23:33 GMT

I've been told that Fusion has no way of showing whether a CAM operation has effectively (that is, accurately) cut the features as designed. Is this really true? It seems you can't even use the inspection tool within the simulation to check things (which would be miserably painful to have to do even if it were possible). You just have to actually machine the part and then inspect it to make sure you didn't make any errors?

Re: Serious CAM simulation shortcoming?

LibertyMachine — Tue, 19 Dec 2017 18:35:34 GMT

No, we do not have any tools at our disposal to actually measure the features in the CAM Simulation. However, we do have a few things at our disposal

1) Collision detection. If you tell Fusion CAM to plunge into material, it will program that, but it will also show up in RED in the simulation and stop if you have "Stop on Collision" turned on

2) Simulation graphics. With the stock setting and it's colorization of each operation, it makes it quite feasible to see where material is left or not.

3) Solid CAM tools. I've grown to trust the toolpaths that I've put out, as long as I've run them through the simulation to verify I'm not gouging. They are solid.

While Fusion is several years old now, it's still a fledgling in some areas. CAM Simulation is one of those areas. It's enough to get the job done, but not enough to dazzle anyone. That being said, I would not describe this as a "Serious simulation shortcoming". Inconvenience, yes. Serious? Not so much. And the work I do? Nothing I do is simple. Aerospace, Nuclear Defense, Oil and gas.

Re: Serious CAM simulation shortcoming?

garmitage — Tue, 19 Dec 2017 18:59:58 GMT

Thank you for the reply. Is there a source you can direct me to for
more information about how to use the "stock setting and it's
colorization of each operation" to identify leftover material? I've
messed around with that a little but haven't found what you are
referring to. And just to confirm, you're saying that any
"gouging"/over cutting would be displayed as red automatically?

Re: Serious CAM simulation shortcoming?

LibertyMachine — Tue, 19 Dec 2017 19:12:40 GMT

What you will see in Red is collisions of tool or holder against what has been designated as "Fixture" or from a tool plunging into a pocket at full rapid. Another spot where collisions will show up is if you try to machine a feature longer than you have flute. The shank will be "colliding" with the part. Feed plunge moves will not show up in rapid.

@mike.mattera has done a great job at putting together the digital "owner's manual" for Fusion 360 and here is the section on Simulation: http://help.autodesk.com/view/fusion360/ENU/?guid=GUIDE1AF5D8C-41A9-4505-AAEA-6CFDD40EDAF4

I'll just toss up a screenshot for how I have mine set to so I can see what's going on:

Each tool leaves a different color, making it quick and easy to see what's cutting where. You can notice up on the chamfered holes, there is some gray bleeding through. That is my model, and I will turn the model off and on to see what's been cut correctly

Re: Serious CAM simulation shortcoming?

Ex_Machina_Engineering — Wed, 20 Dec 2017 19:59:08 GMT

As far as I am aware, there is no CAM simulation environment that will predict the actual dimension of the part.

The finished part's dimensions are a function of tool material and deflection, workholding style and rigidity, servo accuracy and working condition, machine way and bearing condition and more...

But it can tell you if all of the stock has been removed if everything ran as programmed. The same way every CAM does. And you can even save the simulation remaining stock as stl and use it in another setup or measure it.

If someone told you that with Fusion you have to cut a part and measure to check for stock removal, he was probably misinformed.

Re: Serious CAM simulation shortcoming?

garmitage — Thu, 21 Dec 2017 16:01:00 GMT

Can you tell me how it can show that all the stock has been removed? My past experience is with CamWorks which provides color coding of surfaces after a simulation is complete indicating any excess stock of over-cutting. If I use a tool with too large a diameter to fully cut model features, how does Fusion show me that (especially in harder to detect situations like an inside radius smaller than of the tool)? I've looked at the information provided by Seth at LibertyMachine but don't find anything covering this.

Re: Serious CAM simulation shortcoming?

Steinwerks — Fri, 22 Dec 2017 03:17:19 GMT

You can try turning the stock transparent for a visual comparison, but there is no stock levels comparison right now (something I use a fair amount in HSMWorks/SolidWorks).

Re: Serious CAM simulation shortcoming?

Ex_Machina_Engineering — Sun, 24 Dec 2017 15:19:28 GMT

For me, turning visible edges on has never failed me so far. If you can see the edge it means you've machined all the way to it. Especially helpful on those inside corners on milled parts, but works for nearly everything.

If you need a really detailed comparison, you can right-click on the machined stock at the end of the simulation and save the shape as an .stl. You can then do a "Combine" cut to get the leftover only or use it as a second op stock (I do that a lot).