Welcome to CAD Jewellery Skills, a blog I started for the purposes of answering the most common questions people ask about CAD/CAM, rapid prototyping, and 3D printing, specifically as they apply to jewellery design and manufacturing. The goal of this site has always been to provide an easy to follow introduction to jewellery CAD for new users, while demystifying the most complex concepts and technologies so newcomers can know where to begin getting involved.
An Introduction to Jewellery CAD (or “Where Do I Begin?”)
As you might expect, there’s quite a lot to this subject (it seems to me the amount of knowledge required for professional jewellery design is often underestimated). What I have attempted to do in this blog is to provide some starting points for answering many people’s first or most frequent questions, while at the same time providing launching points for some of the most interesting research directions or tangents relating to jewellery and body adornment and their connections to additive manufacturing. In other words, there should be something here for just about everyone keen on this subject.
To save you time in getting started, I’ve assembled below a set of links to help answer the most common questions I have been asked. Some are links to my FAQ pages, others are links to other sites where they’ve gone to such effort to answer the question I felt adding my own answer would be redundant.
- What is Jewellery CAD?
- What CAD programs are available for working in jewellery?
- Why is it important to know manufacturing before learning CAD?
- How does lost wax casting apply to jewellery making?
- How Do Rapid Prototyping and 3D Printing Fit In With Jewellery Casting?
- What are the different types of rapid prototyping?
- What other questions have you answered? (the Frequently Asked Questions series)
- Where Do I Start Learning CAD?
Okay, What is Jewellery CAD? And How is it Different from Other Types of CAD?
It doesn’t take very many Google searches to quickly learn that there are a huge number of CAD programs out there to choose from. Some are general programs, some cover particular specialties. The biggest difference between general purpose software and industry specific software is they’ve tried to include commands and tools to make certain tasks people are called upon to do every day much quicker and easier. In the case of jewellery, we’re talking about ring sizing, determining the weight of an object in metal, and perhaps tools to help with stone setting.
Other industry specific programs would include tools to help with those industries, such as foot model templates and special scaling tools for footwear design, or dioptre measurements for eyewear design, and so on.
For a more thorough breakdown of the different types of CAD software used in different industries, read my other FAQ page on how product design CAD fits in with 3D software in general.
What CAD programs are available for working in jewellery?
You can find a list of all major CAD software used for jewellery here, as well as some discussion of their key differences.
Why is it Important To Know Manufacturing Before Learning CAD?
To answer this question, think if you were going in to a shoe maker and asking for a bespoke shoe to be made. You would expect them to know how shoes were made before they start designing, wouldn’t you? Well, jewellery is no different, even though the amount of knowledge required to make professional looking jewellery is frequently underestimated.
Indeed, it may come as a surprise to you, but jewellers are frequently called upon to know more than any other field of product design before they even sit down at a bench or in front of a drawing pad.
Now, when working with a computer, we have a much easier time setting objects to be exactly the size we want them to be. But we still need to know how big (or small) we can get away with making objects. These limits of size are commonly referred to as Tolerances, and without a proper understanding of these tolerances, we’ll never be able to design anything usable for manufacturing.
How do you learn about tolerances? While you can learn to gauge the size in CAD based on minimum numbers you’ve memorised, nothing beats experience gained from sitting at a bench and working with metal in your hands. This is one of the reasons why I never let anyone into my jewellery CAD classes unless they’ve had some bench experience first.
How Does Lost Wax Casting Work with Jewellery Making?
The lost wax casting process has been a mainstay of the jeweller’s trade for centuries. Below is a summary of the lost wax casting process itself as it typically applies to jewellery (this is the casting process more or less as it appeared in Adolfo Mattiello’s wonderful old book “Techniques of Jewellery Illustration and Colour Rendering”. I heartily recommend the book if you can find it.):
- A master model is made either by carving wax or in a hard alloy such as nickel silver (a copper-nickel-zinc alloy) or often in silver.
- If made in a hard alloy or silver, a rubber mould is made by surrounding the master model with sheet rubber in a mould frame. Placing it in a heated press and vulcanizing it. On cooling, it is cut with a scalpel into halves, thus releasing the master model.
- The rubber mould is used to make many copies of the master model in wax, by use of a wax injector which injects molten wax, often under a vacuum to remove air from the mould, into the mould cavity. On cooling, the wax is removed to give an exact copy of the original master model in wax.
- The waxes are assembled into a ‘tree’ around a central feeder or sprue. This tree is cleaned of dust, and placed in a metal cylinder, known as a ‘flask’. Special investment powder is mixed with water to a slurry and poured around the wax tree. It is placed under a low vacuum to remove air bubbles and allowed to set and harden to form the refractory mould.
- The flask is then inverted and the wax removed by melting in steam or in air in a furnace (the burn-out oven). The investment mould is then carefully heated in the burn-out oven in set stages to the maximum burn-out temperature of 750°C for several hours and then cooled down to the temperature required for casting (typically in range 450 – 650°C).
- The hot flask is placed in a casting machine. The gold metal or alloy is melted in a crucible and then cast into the investment mould. This can be done by centrifugal force or under a vacuum. It is allowed to cool and solidify and is then quenched into water which helps to break off the investment mould material to leave the cast gold ‘tree’. The castings are cut off from the tree, cleaned, assembled into the jewellery pieces and polished.
To help with visualising the process outlined above, this video may be helpful:
How Do Rapid Prototyping and 3D Printing Fit In With Jewellery Casting?
But first, we should clarify the difference between 3D printing and rapid prototyping.
Rapid Prototyping is a form of Computer-Aided Manufacturing (CAM) in which we take a file made using some sort of 3D CAD design program and turn it into a precisely accurate-to-scale physical object. The whole point of this technology is the principle of What You See is What You Get (WYSIWYG). It gets its name from the fact many product designers use this technology to test out their designs before spending the money on mass production.
3D printing is a form of rapid prototyping based around one of a series of technologies. It is not the only type used to produce
We can use this technology to produce items in many different materials, such as wood, metal, plaster, nylon, rubber, wax, and even metal (precious or non-precious). For the purposes of working with lost wax casting, we normally use a 3D printer to create wax or special clean-burning resin which can hold very find details and also can be burnt away without leaving any residue. (essential for lost wax casting).
The 3D printed model is either used for casting (if the model is wax or resin), or to create a rubber mould from which we can make wax copies for casting (if the model is made of a non-castable material). 3D Systems wrote a nice case study on their website showing the process of how one of their 3D models passed through the jewellery manufacturing process from start to finish.
In addition, the 3d Printing Industry Blog has written a good introductory article on 3D printing and jewellery.
What are the different types of rapid prototyping?
In short, rapid prototyping can be broken down into two main types: additive and subtractive prototyping.
Additive prototyping involves starting with nothing and building up layer by layer what you’d like to make out of a chosen material. This is based on any one of several different technologies. One of these technologies is 3D printing. Nowadays, 3D printing is a term often used for the whole category.
Since it started properly appearing in industry in the late 1990’s, it has become increasingly popular for product design because we can create just about anything with it, and produce it in any one of a number of materials without having to go to all the effort of setting up a factory.
Subtractive prototyping involves starting with a solid block of material and cutting or carving away what you don’t want. CNC milling and laser cutting both fall into this category. Even though this technology is much older than additive prototyping (it dates back to 1960), we still use it quite often because it’s fast, cheap, and produces some amazing surface finishes.
What Other Questions Have You Answered?
My list of regularly updated Frequently Asked Questions articles in one handy place:
- FAQ 1 – Comparison of CAD Jewellery Software On The Market
- FAQ 2 – Getting Started In Jewellery Design
- FAQ 3 – Websites, Magazines, and Other Resources for New Jewellers
- FAQ 4 – When 2 CAD Programs Are Better Than 1
- FAQ 5 – Isn’t CAD Taking Away Jobs?
- FAQ 6 – Jewellery CAD As it Fits In With Computer Graphics in General
- FAQ 7 – The Economics of CAD Software, or How to Afford £5000 of CAD Software
- FAQ 8 – Minimum and Ideal PC Specifications for a CAD PC
- FAQ 9 – Best 3D Printers and Rapid Prototyping Machines for Jewellery Manufacturing
- FAQ 10 – 3D Scanners, File Conversion, and Jewellery CAD
- FAQ 11 – What are Parametric Modelling and Direct Modelling
Where Do I Start Learning Jewellery CAD?
Depending on where you are, I can recommend two options:
- You can work through online or video tutorials. I’ve assembled a list of CAD jewellery video tutorials which I have confirmed to be helpful.
- You can take a course, with me or someone else. Through the British Academy of Jewellery, we currently offer several different dedicated CAD Jewellery courses. Each type of course is of a different length and has a different focus. Find out more in their courses section.
If coming to me is too difficult for you, then there may be options where you can take a course closer to your own city or country.
If you’d like to ask a question about training, simply drop me a message and I’ll try my best to answer.