Difficult fillet edge

Rhino
1

Hi Everyone,

I’m trying to replicate the detail of this piece on a camera but I find it difficult to recreate the fillet between both top and side surface.
Classic fillet edge tool doesn’t work so I use a pipe to trim the faces and then create manually a fillet edge but the result isn’t great…
any idea how to improve it?

trigger.3dm (479.4 KB)
any idea how I can improve it?

Thanks

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2

Hi Paul – I don’t know if I’ve taken too many liberties with the design intent here but using strictly rolling ball fillets, I’d make it as in the attached file.

  • The top curved face I take to be a revolved surface from the red curve.
  • the collision among all the fillets at the top of this surface near the circulat part is resolved with a sphere of fillet radius that it trimmed by the ends of the three fillets. (All are the same radius, .1) Only a tiny bit of the sphere is left after the trim.

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image654×971 56.1 KB

trigger_Maybe.3dm (349.3 KB)

(that said, if you make your top surface as a revolved one, the BlendSrf technique you used will probably line itself up more cleanly)
-Pascal

1 Like
3

Dear @paul_duterque
my approach would be the following:

image

the green surface is already tangential to the violett fillet. (and not to the edge)
See layers with construction and curves.
This will allow the fillets meet in a nice Y without an additional sphere / corner

image

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image779×562 50.9 KB

image

trigger_02_tp.3dm (281.7 KB)

hope this helps - kind regards -tom

2 Likes
4

Hi Pascal and Tom,

Thanks for your answers, the top surface was initially a revolve so that’s fine.

Pascal: what do you mean by a sphere of fillet, I tried to untrim the tiny bit left to see what you mean but couldn’t figure it out.

Tom: how do you figure out the initial radius that you have to put as a fillet blend?

Also in general I use fillet edge, what is the difference between fllet edge and blend edge? and is there a difference with fillet surface (appart the difference that you have to selct surfaces instead of the edge between the surfaces?)

5

Hi paul - this guy is a little slice of a sphere of the same radius as the fillets that collide there - the ends of the fillets are all arcs and all share the same center - the sphere goes there and is trimmed by the fillet edges.

image

image

-Pascal

6

Hi Pascal, how do you figure out the center of the sphere?

So I’ve develop a bit more the design applying the same sort of shape but on a different base. It sort of work but it doesn’t end up with a close solid. How can I close this tiny area?
leg 29.01.2023.3dm (1.1 MB)

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image807×691 68.5 KB

7

There’s actually a “test” command(in development or not intended for actual end-user use, they don’t auto-complete when you type them in) for this exact situation called “TestSphericalPatch.” You pick the boundary edges and enter the radius of the sphere.

1 Like
8

Hi Paul - RemoveAllNakedMicroEdges.
The center of the sphere is the center of the edges (all three) of the colliding fillets. More specicically, the centers of isocurves where they collide - that might or might not be the edge of the surface.

-Pascal

1 Like
9

thanks, it worked perfectly