Step by Step Creation of Sculptures Using 3d Modelling, 3d Printing and Resin Bronze Casting

Hi,

I'm a digital artist and sculptor.

I've always been interested in the possibility of turning my pieces into tangible models but due to the restrictive cost of 3d printing I have so far only been able to recreate pieces with a guaranteed market.

For the past year or so I have been creating ornaments for the British Military based on the badges of various forces using 3d modeling, printing and resin bronze casting.

I'm going to take you through the step by step process of creating one of these from initial design work through to completed, cast object.

The steps taken in creating this sculpture are the same steps I take for any piece I make and so by following them you could model anything you like.

Hope you find it interesting/useful!

Mike

P.S. vote for me in the shopbot and makeitreal challenges and hopefully soon I can post up some instructables on making fine art pieces!

Step 1: Initial Design Work

The first step in any design project is to gather reference material...

In this case I have started with the 'Globe and Laurel' badge of the Royal Marines. The final aim of the project is to have a 3d recreation of this badge with as much similarity to the original image as possible and so this it acts as the main reference point for modelling.

However, to make it 3d a lot of modelling will be required and so I scoured the web for pictures of the pieces which I would need to work hard to recreate. In this case the St Edwards Crown and the lion. With any modelling the more reference pictures you have the better. It's important to get them from as many angles as possible to help with accurate recreation.

Next I do some sketches working out how exactly the final piece will go together. There's a big difference between modelling for games/rendering and modelling for printing as in the real world it has to stand up! Therefore there cant be any floating elements, thin joins etc.

Once I've gathered up lots of references and have a rough idea of how I'm going to build it the fun part begins.......

Step 2: 3d Modelling

The next step is to model the sculpture..

There's a huge variety of 3d modelling programs out there (3ds Max, Maya, Blender etc) to try and the one to use depends on the one you 'take to'. They all take patience to learn but are worth it in the end!

Whichever modelling program you choose to use it is important to pay attention to the units you are working in. Your design will ultimately be printed out in 3d so knowing exactly what size the finished object will be is very useful indeed!

You also need to ensure your model has no very thin areas, as these will be prone to breaking when it is printed. 3d printers have varying minimum wall thicknesses so if you work to the specifications of the one you will be using you should be fine.

To help with the later steps of printing and casting I break the piece down into seperate 'components' ; the crown, lion, wreath, anchor are all modelled seperately. But it's a good idea to regularly check them to make sure proportions are correct.

I've attached some images of the wreath showing the various steps of modelling so you can see how most objects can be formed from simple geometric parts which you can then stretch, squeeze, bend and combine to get the final model.

The leaves used in the wreath for example start out as a box which i pull out into the right shape and subdivide to add detail. This basic leaf can then be resized and bent into different shapes for each leaf on the wreath.

For organic and intricately detailed objects such as the lion I use a digital sculpting program (like mudbox, Zbrush etc) to add detail. I create a base mesh in my polygon modelling program then import that model into the sculpting program. From there you can subdivide the mesh (to add polygons and allow for smaller details). The subdivided mesh can then be deformed and sculpted in the same way as a clay piece can be worked. I've attatched an image of the base mesh and finished lion side by side so you can see the difference in number of polygons.

It's a slow process but eventually every piece of the model is complete and ready to be prepared for printing and casting..

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Step 3: Preparing the Piece for Printing and Casting

The next step is to get the piece ready for fabrication. There's a few stages to go through here.

1) First off I work out how many repeated components there are. 3d printing is extremely costly and so if I can reduce how much I need to print so much the better! This is where the benefit of modelling components individually comes in handy. By building the model out of these pieces I can easily identify repeating components. Once one component has been printed it's easy to cast duplicates, saving a pretty penny in print costs. In this sculpture there are a few. The wreath can be broken down into 4 pieces and the base can be split in two etc.The first image in this step shows each component in a seperate colour for clarity.

2) Stage 2 is to alter the components in order to make them perfect for casting. You cant have tight voids or gaps in the centre; these make it almost impossible to cast. If you look at the side by side of the wreath you can see where I have moved the leaves and berrys into positions where there aren't any tight gaps between them. I've also pulled a leaf out at the top to provide a place for the gibraltar scroll to sit on.

3) Last but not least I check that the parts are ok to print. They need to be manifold (watertight) and not have intersecting polygons, floating pieces etc. Luckily most 3d printing softwares have an option to 'shrinkwrap' a model which will automate this process. 3d printing companies also often offer this service. Making it nice and easy!

With everything prepared we're ready to print...

Step 4: 3D Printing

Currently I use a 3d printing bureau service called IPFL, they're incredibly helpful so check them out for any printing needs.

3d printing, or additive manufacturing works by laying down a series of ultra thin layers of material to build up the objects little by little. Take any object near you and imagine cutting it up into ultra thin slices, around the thickness of a hair on your head. A 3d printer will print these slices one on top of the other until the object has been completely recreated. If you take a look at images of printed objects using larger layer thicknesses you can see the stepping effect where each of these layers begins. It's a fantastic technology as it only uses the required material for the print thus reducing waste.

For this project two printers were used. A perfactory machine printing 16 micron (0.016 mm!) layers was used for the really small pieces with fine detail, the larger pieces were printed on an objet connex 500 at 30 micron layers. I've attached images of the pieces below. The perfactory pieces are the lion and anchor. I've put the 1 pence piece in to give you an idea of the scale and how fine the detail can be. The crown on the lions head is a good example of just how detailed these prints can be.

For reference, a 1 pence piece is 1mm smaller than a nickel or a 5 cent euro.

If you look at the anchor and the lion you'll notice lots of vertical columns have been printed too. These act as support for the object as it's being printed and can be easily removed with a craft knife.

Now that we have the printed objects these will act as the pattern for our casting...

Step 5: Molding and Casting

For molding and casting I'm lucky to have an extremely useful piece of extra equipment, an experienced and knowledgable friend! I've asked him to outline the processes and his explanation of the work can be found below...

The molding and casting processes of the printed parts were designed for differing techniques as follows:

The parts printed on the perfactory machine (the lion and the anchor) were printed in a ceramic material which has a high temperature resistance, this allowed us to have the parts "vulcanised". This process involves placing the parts into a rubber that is then heated to almost 200 degrees c. This heat melts the rubber around the parts, creating a mould. This mould can then be used to directly cast pewter, which is an alloy of lead and tin that has a very low melting point but produces small parts with high detail and strength.

The parts printed on the objet connex 500 (everything else) were moulded from using silicon rubber, which produces incredibly fine detail, this involves applying the liquid rubber to the surface of the parts and allowing them to dry around the parts. When the rubber has set, supportive jackets are formed around it to create rigidity and the parts are cut out from the rubber. The mould is now ready to accept the bronze resin to create the finished parts. This is a poly-resin that contains real bronze fillings that mimics the look and finish of real bronze without the cost of the genuine material. For extra strength, metal wire is embedded in the bronze resin in thin, delicate areas.

The parts produced from these two processes are then pieced together to create the form of the completed sculpture. Resin glue is used to join each piece. The finished product is now treated to a minimum of painting and finishing to produce its final finish.

Step 6: The Finished Article

There you have it, in six steps I've taken a 2d drawing to finished bronze sculpture. Result!

I've attached an image of a cast silver version created for a client also.

The processes I use can be followed with any drawing/model you like, all it takes is the patience to model the piece in a 3d modelling program.

While making sculptures like this is quite costly due to the softwares and processes used there is a few options to save on expense...

There's a few free modelling programs, 123D catch and Blender are both good, Pixologic also provide a free digital sculpting program called Sculptris which will allow you to create high detail sculptures.

If you just want to make a one off sculpture you can miss out the casting section competely, the printed objects can be used as they are. Alternatively, you can DIY sandcast multiples. There's instructables telling you how to do this in great detail already so have a look if your interested.

As a medium for art, 3d printing allows us to do things which are nearly impossible using traditional techniques. Hopefully over the next few years it will really take off. Take a look at http://i.materialise.com/blog/entry/ctrl-z-3d-printing-in-fine-arts for an article on an exhibition showcasing some amazing works done using these processes. As more people begin to create pieces in this medium it's popularity should grow. So have a go, you might be the next Picasso or Henry Moore!

Thanks for taking the time to read this. now get out there and create!