Using Taper on specific surfaces


I am doing some parts from SolidWorks Mania (still getting used to Rhino) and I am having trouble using the Taper tool, It is supposed to be on 3 external faces and 3 internal ones:

How would you do it?

SM2003-1.3dm (265.1 KB)

model it from the beginning using extrudeCrvTapered knowing the draft angle, rather than modifing it later. the taper modifier is for the entire object only.


Hmm, I was expecting that. But what about the internal taper?
It was done using Shell and there is that cylindrical part

Hi -

There is no easy way to do this. You will have to create the surfaces manually and then split, trim, and join things up.

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Oh, I see. Was planing to start surfacing after finishing some models first, but looks like I have to start now. lol

Do you know any tutorial/explanation on how to make manually like this?


I tried, just as an exercise, to build this shape using solids and booleans.
Here it is.
… Actually, the solid on layer L5 wasn’t build in a single step: I extruded the curve tapered ‘no-solid’, then Mirror-ed and finally Join-ed and Cap’ped.

It’s been a quick test, I did not respected sizes and angles, sorry …

( Wire frames (curves) are on layer ‘wf’ )

HTH. :slight_smile:

Lucas.3dm (742.5 KB)

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check out the training guides 1 & 2

and a lot of more stuff here

… you ve choosen a quite nice training object especially if you include the precise meassurements and the fillets.
for the fillets you will need workflows described here: Advanced Fillets in Rhino [McNeel Wiki]

without a lot of polishing my file will look like this:
modelmania_connector.3dm (796.5 KB)

kind regards -tom

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@emilio Amazing! Thanks for sharing your method!
I see now that I am still thinking too much on how to do the SolidWorks way. Focusing on sketches (wire frame curves) and doing Booleans later seems to be a better way in Rhino.

@Tom_P Thanks for sharing your model and links! Great job, pretty interesting method. You copied the surfaces to a new layer to work on the fillets, right? And before, how did you create the surfaces on srf layer?

I am actually reading the Rhino Training Manual. I stopped after Lvl 2 - Ch 8 and started doing those parts I have from SolidWorks. Just found some explanation about taped in Ch 10. lol
And thanks for the fillet links too, I will read it. I am having problems with it, and the solution usually is not orthodox.

Btw, I managed to do the taped surfaces. I had to delete the faces, used Duplicate Edges to make curves from them, then Extrude Curve Taped, made a copy from it to use Split twice (plus some Extend Surfaces) and Join. Quite long workflow, never realized how the Draft tool in SW is so powerful.
Still need to fillet it, they all went wrong lol

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yes i like to keep stuff i used to get the final part.
for “real” teaching in the classroom i do it even more than in this fast file i posted.

Because of the dependency of the parallel edge between outer part and the conic pocket a pure boolean approach will fail or will not have any advantage compared to model the single surfaces.

commands i used:
initial grid and curves
_line _rectangle _circle _arc
_offset _move
outer surfaces
_revolve _extrudeCrv
_trim _join
_offsetCrvOnSrf _rebuild
_trim _join
_trim _join
Final Part

But there is a lot of details with point snaps, using correct cplane, axis and so on.
Why do you switch from Solidworks to Rhino ?
kind regards -tom

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Well … that’s my personal way of using Rhino. :slight_smile:
Rhino is very flexible, there is not a single preferred way to build objects.
For example, the cylinder and the box in the file I posted could easily be built without using curves.
Also, different shapes may require different strategies.


@emilio Indeed. It’s a cool workflow to save stuff and be able to modify easily if needed. ^^

@Tom_P Thanks for sharing the commands, I will definitely check the ones I am missing!

SW still is my main CAD software, I started studying Rhino for SubD and some non-uniform lattice in Grasshopper for additive manufacturing; but I stopped to understand the regular tools before diving more into Grasshopper. I am still astonished by the amount of tools available.

Many time I do miss the constraints (for 2D Sketch) and the design tree (for modification), but it been fun this direct modeling approach lol

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Could you elaborate a little more about the fillets, please?
I checked the advanced fillets videos, but this situation is a little more complex. Either on your file or mine I couldn’t get a good result.

I was trying to do this tangent cylinders in the special cases, but I am also getting different results :confused:

Dear Lucas - the Tangent - Cylinder Workflow is the correct one.
If you want to redo it with the file i posted above use the surfaces from the layer without fillets.
Make sure you

  • understood the concept of trimmed / untrimmed Surface first.
  • know how to use _filletSrf
  • use precise point snap
  • i prefere sub-selecting the edges for trimming (ctrl shift + left click)
    kind regards -tom
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just from a more design-view - i think those special corners are nicer when they a not “100% ball like only” fillets.
And as always talking about design , there are different solutions - 2 i use most:


That’s some good looking fillets. Can’t wait to archive this level hahaha :smiley:
Again, thanks for the help ^^