What started out as a quick test for clip joints and small scale has turned into a very elaborate and fun project. The Caffeinator and Prince Chai have now both been completed. With a mix of 80's super-villain and power rangers costume, posed and painted they make an interesting talking point on my desk.

After adding a light undercoat it was time to add a splash of colour. Quickly looking at various palettes for coffee products online I had a rough idea in my head as to what each part of the costume should be coloured. As colours were added some areas were re-done. Mostly changing the tones lighter or darker as parts of the suit were being lost due to similar colours.

To begin with the entire model was given a quick tan coat, this was to help with the next layers of paint but also to remove the possibility of getting white spots in un-touched areas. Starting with the inner most parts (the ones hardest to reach) I then added about three coats of paint  to each section before it became a flat shade without streaks.
For the inner parts I deliberately went over the "lines" so that the next part would not leave behind a blank tan area. For this step and when choosing which part to overlap I favoured the lighter colour to overlap and the darker to meet it. It is much easier to paint a dark colour over a light one than visa-versa.

All in all both models took about two weeks to paint, there were plenty of palette changes in between and little touch-ups as more of the model was completed. Painting the crisp lines and small details were the most challenging and required a small brush, steady hand, but most importantly the correct amount of paint on the brush tip. Too much paint and it spreads out, too little and the colour isn't opaque but appears transparent.

To seal in the model and help the lighting, the figures were given a coat of matt varnish. Without a slight gloss the model appears flat and details are lost.
I'm very happy with how these two turned out and have learnt lots more about taking a prototype virtual model, all the way to a finished product.

Once the printed model was assembled it was time to smooth out the surface. Over the course of various other projects I've discovered that covering the 3D print with a spray auto filler gives the best result. In the past I've used regular spray paint and various undercoat sprays however the auto filler while giving a perfect matt finish also expands a little when drying, helping out with removing the print resolution lines.

This part of the process is the most time consuming as applying a thick or uneven coat results in soft ripples where they aren't wanted. The trick is to know when the coat has enough of a layer to cover the print lines but isn't so thick it'll run and  drip off the model.
Once a few base coats are applied it is time to sand the model. This smooths out any detail and is a chance to sharpen the right angles that get lost when applying the auto filler. After each session of sanding I usually give it another thin coat and repeat the process until I'm satisfied.

The whole process can take one day or it can take a month it is all up to you and your patience/time constraints. Like most art it is simply ended once your happy with the result. For me I'd often return to the workshop and spend a good 40 mins sanding with various grits after I'd had a break from the project. This would often give me "fresh eyes" when looking at the model after working on something else for a week.

Once the model was smooth I applied a base coat of white, again over the course of other projects I've discovered that different "undercoats" produce different results including gloss and rippled/creased finishes as the paint reacts to the auto filler. Though it is more costly than most hardware store spray paint I use Games Workshop Citadel spray paint, it is a fine chalk powder and doesn't react with either the auto filler or other painted surfaces leaving a nice matt finish ready for painting.
At the end or a long slog I have two models glued together, sanded, and Undercoated. Staying with the Disney Infinity theme I wanted to use hobby paint and create a flat finish without the use of dry-brushing or inking. The two models have been named The Caffeinator and Prince Chai and will be coloured with a coffee and chai latté palette respectfully.

Lastly, Spray Auto Filler or Spray Putty is found at car/auto stores, I have yet to see some in a hardware store. In Australia we have both Autobahn and Super Cheap Auto that stock the product.

For this particular 3D print ABS plastic was used, this type of material is the same stuff Lego is made from. ABS is very rigid and is difficult to cut and sand. Another issue is that sourcing a commercial cement is costly however with precautions it can be mixed together using products found from the local hardware store.

For a good solid glue/weld when piecing together plastic models you want both surfaces to melt a little and then create a seam as they are pushed together. With this technique the glued parts are often stronger than the regular 3D print.
Acetone is the ingredient that melts ABS plastic to create a strong weld, a misguided drop on your 3D print can deform a smooth surface and leave a crater.
Acetone is also a very potent chemical and can cause significant injuries from both its substance and its fumes.

To create a cement for gluing ABS parts you'll need off cuts of the ABS and about a cap full of acetone, this can be mixed together in a cup until the ABS off cuts are dissolved, for better results add in more ABS until the mixture become thick. The glue works by the acetone mixture melting part of the model and once joined it'll evaporate leaving behind the ABS particles you mixed into it and create a strong bond.
The problem with this method is that depending on room temperature, the amount of ABS added to the mixture, and how much pressure is applied to the joints will all effect the outcome, on a cold day the mixture can take upwards of 3 hours to cure.

For my mixture I always add in some regular plastic adhesive, otherwise known as acrylic glue. The acrylic glue helps thicken the acetone mixture and also drops the drying time down to around 5 - 10 minutes.
As mentioned above all these chemicals are dangerous, always follow directions indicated on the package, always use a well ventilated room, always wear protective equipment.

The scale was set and the pieces were all lined up in their orientations to minimise undercutting. Some parts (like the arms) were cylindrical and also contained an elbow which made it difficult from any angle to get a print that wouldn't contain difficult areas. In those cases I made sure the smallest parts were orientated up and parallel to the print platform. At the time before printing I wanted to make the model as small as I could and try to match a 6 inch action figure, as it turns out I spent too much time worrying about details that aren't even seen.

One thing that happens when I model is build virtually on a desktop is that the ability to zoom isn't hindered and as a user I can spot errors and missing faces in models that are 0.2mm in diameter and take the time to close that which in the final model are completely obscured by the print resolution (which sits at roughly 0.5mm) in hind sight I could have saved myself some time. Although that was an oversight even more so was the mechanisms I modelled for the clips and plugs. As it turns out if the printer has a volume thinner than the nozzle it'll bypass the object altogether.   As far as using this model as a test ground for future multi-part objects it is well proven. Only after printing did I study more about clips and joints of action figures. Also although it wasn't an error I also realised that models can be broken down and split further to help with print orientations and reduce print-on-air mishaps.

When dividing the model up I broke it in places that would suit moulding and casting. In the instance of the arms it would have gotten better results from printing if I'd cut the cylindrical arms into halves resting the flat side in the print bed. Each print had common errors, such as the wrists collapsing, the biggest struggle though was the head.

Because of its taper I printed the head up-side-down, this worked for printing but left a cavity between the print bed and the divot in the coffee cup lid during the print this area heated up due to the air trapped inside and as layers were added above it retained its heat. This caused the support to fuse with the model and became impossible to pull out. The result is that the false bottom the printer creates on top of the support melted onto the actual model and the only way to clean it off was to grind it with a Dremel tool.
Again this related back to earlier that if I'd broken up the model further, allowing for more flat sides on the print bed the print errors would have been minimal.

With all the benefits of 3D printing a virtual mesh into a physical one the process isn't without its flaws. The way the printer works doesn't allow for great results with shapes like an up-side-down pyramid or objects that overhang from a height. These results aren't broken, they just print at a lower resolution than if it were a right-side-up pyramid. As further example your can print a sphere in one pass however the underside would have more obvious stepping in the layers the print head lays down, while the top side would be sooth and almost perfect. To print the sphere at the optimal resolution it is better to split it in half and print two domes that glue together.

When it come to a complex human figure with arms bend and hands holding objects there is a greater risk that the resolution will suffer as the printer needs to lay down more support structure, or that the components won't print as their angle is too steep and could be knocked away. Even worse would be the final surfacing, the figures head is a simple cylinder shape if it were to be printed at its pose angle it would unnecessarily have stepping on the surface.
For best results on any 3D print the model should be broken into components and orientated to be printed so that overhang and undercuts.

The Caffeinator was cut apart at easy to align places with clips and sockets added in so that the physical model could easily be snapped together. This took extra time but I was eager to test clips and sockets on 3D printed parts as well as the tolerances, plus it would help hold the parts in place while the glue dried. After each part was split and again made watertight for printing. While the image shows the pieces randomly I did lay them out so that the entire model could be printed on one 250X250cm bed. At the time of modelling I was aiming for a 6-8 inch figure but after splitting and seeing how small some objects would be I scaled up the pieces until the longest piece (the stirring stick) would fit the print bed exactly

Positioning the body into a more action-orientated stance didn't take too much effort. Rather than skin, bone, and animate the character I simply selected the vertices that needed to move and then rotated them around where the joint would be. If I'd wanted to print out multiple models in various positions 'skinning' the model would have been the best choice, as I was happy with a one-shot simply moving each limb individually was quickest.

For the reference of the pose I looked up images of Ash from the pokemon series and how he stands with the pokeball held out in front of him. I found that while this looked good from one angle it may not be the best from others. So I re-positioned the legs and spoon-arm until it looked action-hero enough from 360 degrees.
Lastly, before the models various parts (pod, spoon, eyes) where joined together into a single 'watertight' mesh I positioned the eyes to focus on the coffee pod in his hand. While this seems like a no-brainer, having the eyes even a little bit off makes allot of difference to the model, the expression, and its pose and is worth a second check.

Once I was happy with the face I took another try at the body. Keeping it simple I added in some cuff pads, underpants, and some boots, the style behind the suit was '80's action hero' or similar to the 90's American-translated power rangers dressed with some tights and flashy body armour it looks good on film and in comics, but is a little weird when seen in real life.

Switching between low and high meshes when modelling does show misaligned polygons and inconsistencies in the edge layout, especially between hard and soft edges. While this doesn't affect the final printed result splitting polygons the wrong way does make it harder to add in later details or deform the mesh when posing. For this reason I kept the mesh 'quaded' as much as possible. It helps immensely when bending elbows, or selecting edge loops.

The body of the Caffeinator was finished off and a space was cut into the helmet for the face. While the expression didn't quite match in the default stance I knew it would look right once it was finished and the model was posed.

As time went on and again I wasn't able to work on the model, I was inspired by seeing figurines for the Disney Infinity game and wanted to try my hand at some 3D sculpting in that style. In the past I've made plenty of organic models but each of those was low-poly and meant for video games. For this figure I didn't have a poly limit and the higher the resolution the better the print.
By starting out with a low-poly head I slowly added more details and carved in features. Using a method of adding an edge loop, individually lining up the vertices and finishing with mesh deform using a wacom the face slowly came together. I only used Autodesk Maya during this process and toggled between the low and high meshes with the '1' and '3' keys, adding details where it was needed.

After getting the face to a stage I liked I started adding the expression\pose by selecting what would be the jaw and moving the associated vertices around to open the mouth, then continued by puffing out the cheeks, raising one eyebrow while lowering the other. The eyes where separate until the model was ready to print and the iris size and position was continuously changed as the rest of the model was completed.

The idea behind the redesign was to see how much detail can be added to a model before it is lost in the printer resolution. The scale of the Caffeinator would be determined by the idea that I wanted it printed in a single run, which ended up being about 6 inches tall. But I wanted to know if the details of the teeth and eyebrows would even show up, or would they be hidden by the 3D print lines.

The initial idea for the character was a human body with a coffee cup head. By keeping the project simple I could focus on the joints and printing methods I wanted to try out. By tweaking an older mesh and modelling a cup I had a simple mesh of just that. After spending a little more time on the figure I added in a hoodie and made the feet large for better support and to add caricature to the model, it looked ok but wasn't anything exciting. After the first attempt was finished I did a quick pose so it wasn't A-symmetrical as this was going to be nothing more than a base to test out pivoting joints and mechanical connections so I didn't want to spend too much time on it.

I then wasn't able to do anything for about a week, coming back to the model after time had passed I wasn't happy and felt it wasn't 'cartoony' enough and had no appeal. I spent some more time changing the proportions of the character in order to increase the caricature of it. At this point I also added in details to the shoes and refined some of the clothing.

With some more free time I've started a new project. Initially designed to test snapping/moving joints and to also confirm how small details can be before they are lost on a 3D printed model. The character has taken some design changes along the way failed in some areas and has had some spectacular results in others.
Follow along as I wrap up the finishing touches and post the journey from designing CAD design to producing a prototype print and adding finishing touches to it to make a figurine.