2D Chamfer Issue

[jorsborn]

For some reason I am having problems with the 2D chamfer tool all of a sudden. My models have an existing chamfer. I choose the bottom edge as the chamfer path, use a chamfer width of zero and choose an appropriate tip offset. Fusion fails to generate any code however. Can anyone recommend a reason why this straightforward task isn't working for me? Screenshot attached...

[George-Roberts]

Would it be possible to upload the .F3D file?

[fredsi]

Must say, I don't remember it working this way, but....

Once I set the Bottom height equal to the Top height, it generated a tool path. (IOW set the bottom height equal to the model top (Top height) instead of selected contour.)

Fred

[jorsborn]

I feel the same way. I think something has changed here. 

Yes, it works for me as well when I make the change you suggest. Accept the chamfer is not correct in the simulation. The tool is not removing enough material. See attached...

[fredsi]

My bad....should have checked the simulation. Raising the bottom to the top is functional equivalent of not having the chamfer in place.

Revisited the problem and found that it wil also generate a tool path if the Chamfer Clearance is set to 0. Now that should only affect the approach to walls, etc. but seems to be causing problems in this circumstance. 

Fred

[fredsi]

jorsborn,

Since I also use Inventor HSM, went into it to try this out.....saw same failure mode. Seems as though it is tied to the Chamfer Clearance I mentioned earlier. Any value other than 0 prevents a tool path from being calculated. Have posted in the CAM forum to see if anyone can shed light on what might be going on.

Fred

[Anonymous]

Its because of the Chamfer Clearance. You are selecting the bottom of the chamfer and telling the system to put a new chamfer there. When it tries to apply your clearance value it realizes that it will run into the part. 2D chamfer is 3D model intelligent. Select the bottom of a chamfer, set your top and bottom plane to the top height of your model (or that surface that you are chamfering from), a normal clearance value, and it will work totally fine. To put it another way, you are selecting the bottom value of a chamfer (lets say .02 deep) and then telling it to apply the chamfer at this depth rather than from the top surface TO .02 deep.

[fredsi]

While I agree there are ways to make this work, this is 'semantically challenged Monday' for me.

Why would the application of a "clearance" result in running into the part? IOW, how is the clearance being applied? In Z (in the minus direection)? Normal to the tool path vector but into the part? I would really like to see the stick figure or hand puppet demo of what is the intent of this setting or the orientation in which it is applied. Thanks.

Fred

[Anonymous]

It thinks you are running into the part because it is trying to cut the 0.XX chamfer at the bottom of the chamfer, not from the top of the part. If it would cut there, it would run into the model (trying to cut the .02 chamfer from Z-.02, which would lead the tool to cut at Z-.04). The clearance doesn't cause the collision, it just prevents the toolpath from generating when you have the planes set up wrong.

[yourlittlecncshop]

One of the things I've noticed is that the 2D Chamfer op doesn't seem to behave very well when dealing with existing chamfers. In this instance, I would use a 2D Contour and then choose the chamfer checkbox to set my tip offset. The only time I use 2D chamfer is if I want to put a chamfer on a sharp edge in a model, or if the chamfer runs up against a wall where I'd have to manually program the clearance in a 2D Contour operation.

[jorsborn]

The more I play with the 2D Chamfer operation the less I understand. Minus the interference bit, I am going to stick to 2D Contour ops. The 2D Contour always seems to get me what I want. In my opinion, the 2D Chamfer operation still needs a lot of work as it's just not intuitive.

[yourlittlecncshop]

I feel the same way about the Trace operation. 😄 (Some days it works GREAT for making 3D chamfers, other days it won't generate a toolpath at all.

[fredsi]

No doubt the Autodesk folk will correct me .....

I would say the strategy is mis-named to a certain degree; not really 2D Chamfer, but rather it is a form of Auto deburring. It seems to be intended only for sharp edges (as others have mentioned). Further, the phrase 'Chamfer Clearance' doesn't really descirbe the fact it is an additinal offset to the automatically created clearance when the tool is about to encounter a vertical wall and the like.

I think the instructions/videos would benefit from 1) a clear statement about use for sharp edges (deburring);  and 2) a graphic to show the effect of 'Chamfer Clearance' on the tool path as is done with other parameters. My $0.02.

Fred

[Steinwerks]

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@fredsi wrote:

No doubt the Autodesk folk will correct me .....

I would say the strategy is mis-named to a certain degree; not really 2D Chamfer, but rather it is a form of Auto deburring. It seems to be intended only for sharp edges (as others have mentioned). Further, the phrase 'Chamfer Clearance' doesn't really descirbe the fact it is an additinal offset to the automatically created clearance when the tool is about to encounter a vertical wall and the like.

I think the instructions/videos would benefit from 1) a clear statement about use for sharp edges (deburring);  and 2) a graphic to show the effect of 'Chamfer Clearance' on the tool path as is done with other parameters. My $0.02.

Fred

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It's not just vertical walls though. It will clear floors and angles that are affected by tip offset and tool diameter as well, which is why it avoids the modeled chamfer unless the clearance is set to zero. The tooltip could use a little refinement for sure.

[Anonymous]

I don't know if you have solved your issue yet but I was able to use the 2D chamfer tool on a part modeled with chamfers. 

1) Model your part with the chamfers

2) Machine your part till you're ready for edge breaking

3) Start the 2D Chamfer operation

4) In geometry selection, select the bottom of your chamfer

5) In heights selection under bottom height, selection the top of the chamfer

6) In passes selection for chamfer width, enter the size of the chamfer. When modeling, if you used a .010" chamfer, enter .010" in the chamfer width box

7) Fill in desired Tip offset and Clearance and press OK

Hope this helps for all the people out there that are like me a need to model in all my edge breaks 🙂