Wow ok i see what you mean by "expensive" as you need to get two printed that makes this ankle buckle 70 CA$ for me....
and when i have a master for molding, how much would it cost to cast some rubber inside it x 2 ?
What kind of rubber ? I don't know nothing about molding and rubbers ^^
After, I guess the sole would be the most expensive part to make... (But I need one) :-D
yes, probably the branding problem for the heel cups... He sould made them anyway but without the nike mag on it and we could add it by ourselves
seriously, these shoes are driving me crazy
Yeah maybe that could have worked.
So you buy the prints. Then you have to fill the inside with a clay that has been tested and proven not to contain any sulfur. I used Plasticine for this part. You need to make a base so the part sits up at least 1/2" (12.7mm). You need to plan how you intend to fill the mold, plan air vents and also add some "registration points" for the 2nd part of the 2 part mold.
You build a mold box around this that is at least 1/2" higher and wider than the largest parts of the master part. You have to make sure this wall is "water tight" right around your part so your silicone does not leak all over the floor.
Silicone costs about $70/KG and you would need at least 2.5KG per buckle. If you want good molds, then you need to degas the silicone and therefore need a silicone that has a long potlife (over 15min). Once you mix, degas and pour the silicone, you have to let this part cure properly before de-molding. By demolding, you only break away the wall so that you can lift the block of rubber and flip it over and pour the 2nd part of the 2 part mold. Once you demold, you then have to remove the clay without disturbing the master part. If the master part comes out or breaks the seal at this stage, you have to start all over again.
Once you have the inside all cleaned out, you can set you plugs for the air vents and get ready to pour the 2nd part.
When I get around to doing this, I will make my inner part fit like a plug inside the outer part so there can be no leaks. You often see 2 part molds being made with a seam right down the middle. based on my experiences, this not the best way to do this. In the case of this part, you also want to create a seam that follows the thin edge of the part so you don't have to clean up the surfaces later on.
I would also leave a small amount of clay (smoothed out) inside the master parts so as to make the wall thicker. I would also sculpt a battery box out to allow a 9V to sit inside the cavity later on. You can even add channels for the running of the wires.
So once the molds are made (say about 5KG of silicone is used), you then have to mix and pour an flexible rubber into the molds so you parts are also flexible. I think the same rubber I am using on the clear soles will be ideal for this. I will have to mix a white pigment into the clear prior to degassing.
So not cheap for a one off and why the 3D printed parts is actually an affordable option. I'd say at a guess, a pair of cast rubber buckles will end up costing $60 to buy.