3D printing a 1/10 scale figure
I created this figure for the Tsunacon 2013 convention in the Netherlands of their mascot character. This is the third year I make one for this convention. Trying out some slightly different 3D printing techniques every time.
For the body parts and stand I used ZCorp full color printing, this is a powder-based printer that works like an inkjet that prints binder material and colors, and this time I finished it to a smooth level. For the clothing I chose EOS selective laser sintering nylon for the clothing and details, this machine is similarly powder based, but uses lasers to melt the powder together, and the material from this one is much stronger as well. I had everything printed at Shapeways, which is a 3D printing service in the Netherlands; the materials are called Full Color Sandstone and White Strong & Flexible respectively on their website.
The design of the figure was started late December, drawing some stuff on paper for a redesign of the clothing and some rough sketches for the pose. I wanted the design to show off some more skin this time. Modeling work was started early January. Some parts of last year's model were re-used to save time, such as the hair, and tweaked to fit the new design. The model was ready for print halfway January and sent to Shapeways. Meanwhile I had exams. The parts arrived somewhere in the past weeks, and I did the finishing and assembly in the last week. So, the entire thing took about a month and a half, a bit rushed though.
I create the model using 3ds Max entirely. Making use of a lot of morphs to tweak important body parts.
Hollowing and cutting the model into pieces is hell.
Using Netfabb to check the thickness of the parts. The nylon material needs at least 1mm thickness, the color material needs 2mm.
Last time I had some difficulties with getting the pieces assembled easily, as you cannot really specify or rely on any tolerances with 3D printing. I came up with a way that uses the flexibility of the material to create a plug that works without manual adjustment. It works simply by separating the two directions and using flexible bars with minimum material usage so the opening can resize by itself. This is possible to do with 3D printing, as one of the advantages of SLS printing is that we can create complex structures inside of the model.
The downside of powder-based printing is the powder. It gets stuck behind the plugs.
Here I'm using high-tech equipment such as a toothpick and blowing air into the parts to get the powder out. Wouldn't want too much of this white powder to get onto the black printed parts.
It seems some plastic from the tumbling machine got stuck inside my model. Looks like the plugs are the perfect size to get these stuck inside.
The white parts, all cleaned up.
And the plug works perfectly!
Just look at the detail of that ribbon!
I've put these ribbons together on a sprue to save the printing guys some time. It's a bit of work to figure out which ribbon is for which part, though!
Like last year, I opted for full color printing on a ZCorp machine for the body parts. This is a very grainy and rough material, though, and you can't just sand it down as the powder is pretty rough and you'll pretty much just destroy the coloring and detail. So what I did this year is use a technique I've been experimenting with to get it almost perfectly smooth.
What I do first is use the finest buffing accessory for my Dremel, the 512 S abrasive buffs more specifically. I've tried different ones, this is the only one that didn't damage any details. The only thing I can remove with this are the roughest edges of the layers, and the tips of the sandy surface. This step is necessary for the rest of the process to work.
After that I spray on some primer, let it dry. It's very important that you let it dry. Then I spray on many many thin layers of acrylic-based glossy varnish, with hours or days of waiting inbetween. If you apply too thick layers it'll take painfully long to dry. At first it will not look glossy at all, then it'll start looking like glossy cloth, and a few layers later it will be very very glossy with some slight wobble where there's heavy stepping. After that has dried I apply a last layer of alkyd-based matte varnish.
The downside of this trick is that it takes quite a bit of time and work, and it's perhaps actually easier to just work with a higher resolution print and paint it manually.
Same is done with the heads.
The hair is done the same way as I did last year, but this time using polished material before spraypainting. It came out pretty well.
You can see the color printing resolution used for the face isn't too high, so the eyes look a bit blurry.
Assembling everything. This goes very smoothly. Didn't need the glue.
Ehh... Needed this open to make it possible for assembly. Seems like the added thickness of the body makes it not close completely... I'd better take that into account next time.
Obligatory picture of my workspace. It's actually cleaner than usual, because I need to make sure not too much dust gets onto the figures.