Toolpath Simulation Crashing Fusion - Only with One File

[Anonymous]

Hello all!

I have a showing a problem I am having on a file (this file). I added a link to A360 because it has linked parts, so I couldn't get an f3d.

In Setup1 and Setup3 you will see 2D contour toolpaths with a very very thin tool - this is our occilating knife (tool 31).

For some reason, this toolpath (or any toolpath created with this tool with the selected contours in this file) crashes Fusion when you try to simulate it. This only happens with tool 31, and only on this file.

If you edit the broken toolpaths, set the tool to something different, it simulates the toolpath. It is only our tool 31 that crashes on toolpath simulation, and only on this file. We've used this tool 31 on many files over the last 3 months.

We're sending it to the machine and will air cut it to see what's up, if it runs okay, but we're a little twitchy about running something without seeing the simulation of the toolpath first...

Thanks for any help!

[jeff.walters]

I would say the main reason for the crashing is the tool definition. You have a .0001in diameter taper mill with a .0607 corner radius. I think you have a typo on the Diameter going on.  

[Anonymous]

Hi @jeff.walters

Funny as it sounds, that isn't a typo.

The reason the tool diameter is so small, is because the knife needs to travel ON the cut line - no compensation - but all of our other tools need compensation. At first we just tried to "remember" to switch the tool compenstion in each knife toolpath, but after we wasted two sheets of (expensive) foam we gave up on that and made the knife very thin. (I wish compensation could be set tool-specific in the tool library, but that is another discussion).

Functionally, the knife has zero thickness - it only splits the foam, it doesn't remove any. In reality, the thickness is still very small - a little less than 0.0625". The space from front to back is 0.25" at it's thickest and the knife is 4" long. (I attached two pictures to show our knife). We also have a 3" knife that is even thinner.

The corner radius is just what was autopopulated. Should it be 0.0001? Or will it define what corners our knife can go around (in our case, 0.25")?

The thickness being 0.0001 is just because, on a few of our jobs, the tolerance is +/- 0.001 (I know, I know, small) and I didn't want tool compensation to mess up our tolerances/end product. So I added another zero.

Is there a different method I should use to model our (thin) knife that doesn't invole switching compensation in the toolpaths constantly? Or is that what I need to do?

Finally, we've been using this same tool for about 3 months and haven't encountered this error - if I get this one file working, then can I just go about my business? Or is my setup just begging for more trouble down the line?

Sorry for the long reply - I'm not really familiar with tool setups - I am design and CNC in our company so I'm spread pretty thin. In our old program, the tools were set up by an outside company. This tool library I set up on my own. I'm not interested in perfect tools in the computer - just perfect results off the machines. The only way I found to do that with our knife is by pretending it's thinner than it is.

Thanks for any assistance!

[Anonymous]

Hello again @jeff.walters

Sorry for the quick double post - I got it to work on a new file!

I attached the f3d of the working file.

Definietly something about that one file in particular that made it crash with the one specific tool - I can see these two files have the same contours selected, using the same tool, etc. but this one (attached) works when simulating the toolpath and the other one crashes.

Definitely a situation where I may just shrug my shoulders and move on.

[jeff.walters · Accepted solution]

If you set the corner radius to 0 the crashing will go away. At best with a .0001 diameter your corner radius would be .00005. 

[Anonymous]

Thanks, I'll do that