Radius/Fillet Question?


Fillet problem…

Attach:Rhino 5 CAD data : =
Rhino part design.3dm (715.9 KB)

Better to forget this kind of situation with Rhino … :slight_smile:


Forget about it in SpaceClaim too. :smile:

Those R1 fillets are too large.

This can be done easily once you remove the top fillet and create a tangency match between those surfaces. Then create the fillets in 2 steps to allow them to flow. Trim out the problem intersection area. Use sweep 2 rails using a poly edge and joined dup edges of the fillets. Use the rebuild option set to 7 points. Match that surface to all the edges with preserve shape, closest points and refine match.


The finished result is water tight. This is admittedly pretty tricky work to do.

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Those fillets are a lot smaller than 1mm!!

Try it using the values the OP requested.

Well I can’t do the impossible obviously. The largest fillet possible is .2 mm.

How’s this, done in Fusion.

Rhino part design.stp (253.3 KB)

This is my solution in Rhino.

Rhino part design2.3dm (791.1 KB)

It’s really impressive that Fusion can handle this.

Onshape does a nice job until you increase the fillet size until the fillet touches that notch in the front. It can’t do it. The best it could do was around 0.7mm. Here is what that looked like:

or this if you change the order in the history tree:


thanks everyone…

Dear DanBayn super , How did you ?

It was easy with Onshape, except it fails to meet the requirements of the 1mm fillets. I don’t know Onshape well enough to say definitively that it absolutely can’t be done, but I can say the solution is not obvious.

So back to Rhino. Here is my version with 1mm fillets. More steps then there should be, but it can be done.

I’ll attach the file as well. FYI…It’s a closed polysurface if that’s helpful.

Rhino part design.3dm (987.8 KB)

So I guess Fusion might have come out on top in this challenge. What we don’t know is whether Fusion did this easily or required more work then just picking the edges,


I had to cheat a bit and delete the 0.25 rad, easy in Fusion just select and delete and Fusion untrims back to a sharp corner. Then pick the edges add the 1mm rad and put the 0.25mm rad back. Probably less than 2 minutes for both sides. Fusion will sometimes fit a bigger rad around a small rad but not this time.


Many thanks dear DanBayn and all…

How to delete the radius?

karsilik rhino design.3dm (819.5 KB)

Unfortunately, there’s no “Remove Fillet” command in Rhino 5. You could easily delete those surfaces extend and retrim the surfaces. That would only take a few minutes.


What I did was take your model to Onshape and remove them there. Onshape is free and I’m finding it to be a useful compliment to Rhino on the odd occasion (like this).

Here is the result:

karsilik rhino design without fillets.3dm (791.2 KB)

For the lazy below a link to onshape.

Thanks Dan for the info


Dear DanBayn and all many thanks ,

Results: onshape fillet add/edit/remove face…
Karsilik.step (683.2 KB)

Hello 3Drawing_net
Glad you got it sorted, my belated attempt is attached. I wasn’t able to use 0.8mm round the edges already filleted though (god knows how Vittorio managed it). There is an excellent tutorial ‘modelling complex transitions’ by Brian James which deals with this situation. You can find it under additional videos on the Rhino website. The real reason I’m posting is to ask how you got those ‘X’ shaped isoparms on the shoulders of your model. I don’t recall seeing them before. Is there a command that rotates isoparms?Rhino part design.3dm (822.8 KB)