How to create a ring (jewelry) with a varying cross-sectional profile (varying height and/or width)

DavidPhillips

I'm new to CAD/OnShape, trying to do as stated in the title. I am not sure if there is a standard way of designing a shape like this, but ideally I'd like to specify multiple profiles around the band of the ring (say, at 0, 90, 180 and 270 degrees) to sweep between (interpolating the shape of the resulting solid between each profile) along the path that the band defines (typically a circle). The problem is I understand that OnShape does not currently support sweeping through multiple profiles (just one profile that is used for the entirety of the sweep). Is there a solution to this problem, or perhaps a different way entirely that is generally used for constructing a ring model?

An alternative approach that I've dabbled in which may be the way to go is to sketch the side profile of the ring as a circle for the inner edge, and a spline for the outer edge to allow for arbitrary depth of the band (ie distance between the spline and inner circle). This encloses a surface between hte spline and circle which can then be extruded to produce a solid ring band (though I would then need to figure out how to vary the height of extrusion so that the both the depth *and* width of the final band can be customized...)

Thanks,
David

owen_sparks

Hi @david_phillips715, yes what you describe is do-able.  Welcome to the forum BTW.

(a) First up I'd recommend you get the multi-plane featurscript tool.  If you've not used FS things before they're additional tools written in the native OS language by anyone who cares to, and are used to add custom functionality, and are pretty cool.)  

(b) Draw a circle on a sketch and then use this tool to make new planes about this circle.

(c) You're correct the sweep uses a single profile, but a loft can use as many as you like.  Hurrah.  So put sketches on each new plane and make the profiles you wish on them.

(d) Loft through these sketches (as a solid) to create your part.  The loft will create a smoth transition for you, but the more planes the more intricate you can make it.

(e) Lean back and bask in the glory of your design / post a screenshot here so we can see.

Oh and if you want the design to be symmetrical then it may be quicker to model just half of it, then use the mirror feature to instantly make the other half. 

Owen S.

owen_sparks

Hi @david_phillips715, yes what you describe is do-able.  Welcome to the forum BTW.

(a) First up I'd recommend you get the multi-plane featurscript tool.  If you've not used FS things before they're additional tools written in the native OS language by anyone who cares to, and are used to add custom functionality, and are pretty cool.)  

(b) Draw a circle on a sketch and then use this tool to make new planes about this circle.

(c) You're correct the sweep uses a single profile, but a loft can use as many as you like.  Hurrah.  So put sketches on each new plane and make the profiles you wish on them.

(d) Loft through these sketches (as a solid) to create your part.  The loft will create a smoth transition for you, but the more planes the more intricate you can make it.

(e) Lean back and bask in the glory of your design / post a screenshot here so we can see.

Oh and if you want the design to be symmetrical then it may be quicker to model just half of it, then use the mirror feature to instantly make the other half. 

Owen S.

owen_sparks

Sorry just rereading your post again, you may also wish to look into using variables to define some of the dimensions of your ring.  It's then as easy as changing a couple of numbers to rebuild the model to different finger sizes / profiles.

Owen S.

DavidPhillips

Thank you very much for you response (and the welcome), Owen. I had actually tried the loft tool but wasn't able to get a satisfactory result. But I just discovered the "Guides" option which indeed allows me to use the band path (circle or whatever) to perform a fully cyclic lofting with smooth continuity around the band! I'll have to check out featurescript... I get the feeling tools like multi-plane may help my workflow a lot. Thanks again.

owen_sparks

Hi @david_phillips715
No problem, happy to help.  
BTW did you accidentally "vote down" my answers or did someone think my answers were rubbish?   I find myself surprisingly upset to have received them!  Grrr.
Cheers,
Owen S.

DavidPhillips

owen_sparks said:

Hi @david_phillips715
No problem, happy to help.  
BTW did you accidentally "vote down" my answers or did someone think my answers were rubbish?   I find myself surprisingly upset to have received them!  Grrr.
Cheers,
Owen S.

Oh dear, I think that was me by mistake (odd, I could swear I remember clicking "Vote Up"). Indeed I meant to upvote. Should be fixed now  . Have a nice day.

brian_sweet

I am super new to 3D printing and CAD, but love it.  So i am tying to make a simple ring with diamond cut outs.  It was easty to do an offset plane and extrude out the one diamonds.  Now I am trying to figure out how do do that all the way around.  Played with the Circular Pattern but that was not working.

That is my work in progress. 

https://cad.onshape.com/documents/665c0ed5ebd690d47908381b/w/8d731be1cdd8f44a59e9eede/e/0157ae2f40c73d8a1d0e4ec2

dirk_van_der_vaart

Some hint's. I took your document and made something different
Take a look at Part studio 2, a small example of what you can do with configuration's
https://cad.onshape.com/documents/cb5ba6d3468bcb20b1ed913e/w/cf9836594bd912bfce6de8d2/e/a834ffc829659b3ce65a123b