Trouble with Fillets

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 From:  Scooter (DORMANTVISION)
6624.1 
All,

I'm having a bit of difficulty getting one of the two attached gears to fillet.
Both are a solid and I can get the larger gear to fillet, using a value of 2mm.
Trouble is that I can't seem to get any fillet at all for the smaller gear not matter what the value.
I've tried this in both V2 and in the latest beta.

Any help would be appreciated.

Thanks,

Scott

EDITED: 11 Apr 2014 by DORMANTVISION

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 From:  Michael Gibson
6624.2 In reply to 6624.1 
Hi Scott, part of the problem is that filleting doesn't like things that are coplanar to be in separate fragmented pieces rather than one big plane. It's this area here:




With that top replaced with just one single big plane as in the attached 3DM file, that should help it to fillet better. That seems to fillet at radius 1 or 1.5 ok, but not much larger than that, not sure why that is.

- Michael

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 From:  Michael Gibson
6624.3 In reply to 6624.1 
The other problem area is where these edges meet up with one another:



Those 2 edges there are not quite smooth to each other - they're nearly smooth but actually have a slight 1 degree or so angle crease in their end tangents where they meet.

That kind of "nearly smooth but just not quite" type of shape is also difficult for filleting, when pieces are not smooth to each other often times the fillets constructed there do not naturally meet up without some kind of corner juncture being made, but when they are so slightly angled the corner juncture becomes a little slivery thing that's difficult to trim and cut properly.

Also as the fillet radius becomes larger the fillet sticks out more to either side of the juncture area and the small tangent deviation becomes more problematic...

So if you want to get a fillet of larger than 1.5 on that, you may need to redraw those pieces to be more accurately smooth in that spot. Either that or have it come to a somewhat more distinct sharper corner and let it get rounded off by filleting as well. Filleting basically likes this to be either really smooth to one another or fairly more distinctly sharp to each other, when it's "almost smooth but not quite" like you've got here (like maybe up to 4 angular degrees or so tangent deviation say) that tends to be problematic for filleting.

- Michael

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 From:  Michael Gibson
6624.4 In reply to 6624.1 
Hi Scott, I've attached here another updated version, here I sort of patched that very slightly sharp area by cutting away a bit to either side of it and putting in a blend surface, replicating that with Array circular, then rebuilding the top and bottom caps.

This version should fillet better yet, it can go up until the fillets start to run into each other about radius = 3 or so max.

- Michael
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 From:  Scooter (DORMANTVISION)
6624.5 
Thanks Michael for your time, efforts and explanation.

Scott
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