Why can’t CADs accurately show the height placement of a stone?

[lissyflo]

I’m having cads drawn up for a pendant and I’ve asked a couple of times about the stone being set at a specific height. The designer has told me that cads can’t accurately reflect what the height of the stone within the setting will end up being as the setter will decide, on setting, how best to safely place the stone. I was really surprised and haven’t been told this before. I understand why a setter would need some leeway, but I’m not keen to sign off on cads that show the stone at a height that isn’t what I truly want? I don’t understand why the cads can’t depict the stone in my perfect position (assuming it’s physically possible), so the setter knows my ultimate aim? We’re ultimately talking about a difference of a couple of millimetres, so maybe it’s the blown up size of the drawings exacerbating it?

The height of the stone makes such a difference to a setting - I’ve seen pictures of rings I adore from the top view but that I actively dislike in profile, purely because the height of the setting is not my taste. It’s something so fundamental to whether you personally enjoy a setting.

If it makes a difference, the stone is a cab. I’ve only had stones with a girdle set before now, so maybe that has an impact that I’m not understanding?

 

[yssie]

A designer can show stone placement within prongs in CAD images, but doing so is pointless from a manufacturing perspective.

Computer Aided Design (CAD) is used to create moulds into which molten metal will be poured - the cast process. When rings are cast, the prongs are simply long metal straights - much longer than needed regardless of desired final stone height. This is true of hand-forged rings as well - initial fabrication is of those same long metal prong straights. Prongs will be shortened and prong-seats cut in during the setting stage.

Showing stone height in a CAD shows the client that the jeweller is listening, but serves no practical purpose in terms of execution. Not showing stone height in a CAD also doesn't mean the jeweller isn't listening this is a conversation to have with your vendor.

 

[lissyflo]

Thank you so much, Yssie. I get unsettled by things I don’t understand and that explains it perfectly. I will clarify again my ideal preference when I approve the cads and trust they will aim to get as close to it as possible.

This site is amazing - thank you to all the highly knowledgable posters for the time you take hand-holding and explaining. It’s much appreciated!

 

[yssie]

No worries! It's too bad the vendor didn't take the time to explain it and make you feel more comfortable

 

[lissyflo]

I don’t understand why either. I’d asked a couple of times about the stone’s height in the cads and was told both times that the setter decides, based on safety, whilst setting. Which is fair enough, but doesn’t imply that my preferences will be strived for if at all possible. A quick statement to explain why the cads are as they are, as you did, and to say that my preferences will be passed on to the setter but may not be entirely possible would have cut off any concerns or niggles on my part before they even arose. Especially on something as divisive as stone height, which can completely change the tone of a setting.

 

[sledge]

Communication and understanding is key with any project you build, rather jewelry related or not. I've not ran jewelry CAD programs but have used a few different CAD programs in general. Showing a diamond and dimension isn't a hard process to do, especially if it gives your customer the warm fuzzies.

You could easily put a +/- after the dimension with an asterisk and below put a note that explains that distance is for visual purposes only and final exact height will be determined at time of stone setting within a certain tolerance.

The jeweler wants to meet your intended desires, but sounds like they want to be truthful it may not be exactly 5mm, or whatever height you specify. There's a difference between meeting intent and final being at 5.25 for instance vs 8mm. I dont think the jeweler is trying to be dishonest, but rather not communicating perfectly so there is some confusion still.

Have the talk with them and I think you will come to same conclusion.

FWIW, here is an early CAD version of my fiancee's ring. DK showed the setting height in all revisions. But part of this had to do with the halo swirls around the diamond and how we had to maintain a certain air gap visually so the vertical height was partially controlled by the exact size of the diamond and also the horizontal controls needed to maintain the airgaps.