Simple sketch fillet not working?

[alphatester77]

Hi folks,

Quick one - in attached file, I'm trying to just add a simple fillet to the corners of the rectangle and fusion is randomly working on two corners, but not on others.

Reading reddit, it seems most folk seem to think Fusion is just very weak at it's sketch filleting, eg:

https://www.reddit.com/r/Fusion360/comments/y1z0ir/why_do_i_have_such_a_hard_time_filleting/

However, I'd like to at least try and understand how the software is attempting to operate and learn to workaround it - I mean I've just dragged a rectangle and clicked 'add fillet' and it's failing....!

[HughesTooling]

The problem is the midpoint constraint, if you remove it the fillet will work. That said, best practice is to leave the sketch as simple as possible then add the fillet to the body after extruding. Simple sketches are more efficient and more predictable when edited.

[alphatester77]

Ah thanks, that's the workaround - that K's for the tip. Any reason that  midpoint breaks it?

Regarding best practice, is there any logic to this or is it just to avoid the buggy bits?

Ie it seems more logical to have sketches that represent the sketch (much like telling an architect to leave door markings or round walls off his sketches, it would seem to create multiple points of logic transference which would create challenges)

This design for example I'm wanting to send to a CNC and have a matching insert, but I guess the sketch won't be able to represent the actual sketch if I leave all fillets/curves off my object.

[g-andresen]

Hi,

If you require a DXF for external service provider, you can obtain this by projecting the required contours of the object (including fillets) into a new sketch and then saving this as a DXF.

günther

[alphatester77]

....

[TheCADWhisperer · Accepted solution]

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@alphatester77 wrote:
 Any reason that  midpoint breaks it?

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Simple logic.

The Fillet would shorten the line which conflicts with the existing midpoint.

[alphatester77]

Ah, thanks @TheCADWhisperer -that makes sense 

You should be hired by the fusion team to write their error messages, it'd save a load of confusion!! 😂😂