I was only 13 when I first started working with resin and silicone but it was solely on Architectural models, I neither had the time nor the right equipments to work on my own resin toy until now…
So I thought I would share with you the steps involved in the making of this resin Toy, for those interested in making your own resin toy, I think this tutorial might be very useful to you.
For this project I decided to use a doodle I made for a Cowly’s fan during Halloween 2014 in Japan and used it as the base for this toy.
the first step is a no brainer, just sketch and put on paper what you have in mind. You might want to leave it sitting on your desk for a while as in my experience, on a second look it is always easier to spot what might be wrong with the concept and make change accordingly to make it more appealing, before you start working on the actual toy.
Once I got a good feeling for my sketch it’s time to start the Digital Sculpture.
As usual I fire up Zbrush and start working on the digital sculpt at a low ploygons level, then slowly step it up.
( As seen in the following image)
Since this Sculpt was meant for resin I digitally embossed Cowly’s name as well as the year underneath the model to make it more pleasing to collectors, this also helps me to keep track of the silicon molds.
After tweaking the 3D sculpt to my liking I settled on a 3″ toy, then it was time to merge the 3D protoype and digitally hollow it out to get it ready for 3D printing.
if you are not familiar with 3D printing, hollowing your model allows you to save on 3D printing cost by using less resin from the printer, usually the minimum wall thickness allowed is 1mm, having a 2mm wall thickness will double the price of your prototype, so it is quite important to get this step right, you will also have to decimate the polygons of your models in order to squeeze your digital prototype to a file size of about 60mb or less otherwise the printer most likely won’t be able to print it.
For this step you will need some standard 55 Plastiline grey clay as well as some materials to build a box, in my case I am using Lego bricks from this website to get the exact bricks I need, but if you don't have legos laying around you can always use wood or anything else for that matter.
Depending on your prototype you will now have to think whether you will need a one part mold or a multi parts mold. If your model have a flat base then a one part mold is the way to go, but if your model is very complex you might need to split your mold into 3 or 4 parts, although it is easier to remove the resin replica out of a 4 parts molds you will end-up having more post-production work to remove the seams. For this model I decided to go for a two parts mold, that way I can get it out without breaking the resin cast or the mold.
Once I have a clear understanding of where the seams should be, I start building a small box around the model, just tall enough to arrive at my first imaginary seam.
then I remove the model from the box and use clay to fill it up, ( make sure you press firmly on the clay inside the box or else you may have trouble with it collapsing under pressure )
Now take the model an press it hard inside of the box and inside the clay, essentially we are making a placeholder of the first half of the mold out of clay.
Once you managed to press it to the right position make sure the clay that meets the model is flat and clean, this will end up being the seam of the mold and it will make your life much easier if it is done properly the first time.
the next step is to add some keys on the clay so when we put the two parts together there is only one way for them to fit. In my case I am using those Cap nuts.
They are great because the base have flat sides so they will lock in place and the rounded top makes it easy to match when the two parts are put together. Make sure you fill them up with clay before applying them around the model they will stick better that way. Alternatively or in addition you can use a stick with a rounded tip to randomly poke holes around your model.
Once your keys are in place, keep building the lego box until it's taller than your model by around 1cm.
In the Modelmaking world usually two kinds of Silicone are used to make molds, the first is a condensation cure system and the second is a platinum-catalyzed cure system, So why two? well they both react differently with the resin you are planning to use, for instance if you are planning to make a crystal clear resin model, you will need to use a platinum cure silicone, otherwise you will end-up with webbing and imperfection, the downside with this silicone is that it cannot stretch very well, so your mold might tear up or get deformed over time, for any other resin I recommend to use a condensation cure system, it has more elasticity so it's easier to take your piece out of it and the shape of the mold will remain the same over time. Also it is important to point out that silicones have different density levels for instance a harder silicone is better for one parts mold, it has a lower shrinkage and will retain more details because of that it will also yield more resin duplicates. Since I am doing a two part mold and my model is quite complex I am using a softer condensation silicone in order to have more stretch resistance so I can take the model out without ripping the mold apart .
to be continued...