DIY C3/N3 Remote Control Plug for Canon DSLR

As most of you already know, some Canon DSLR have a dedicated plug for the remote. This is pretty annoying, especially when we want to make a special diy shot controller. The easy way is to buy a cheap remote and cut the plug from it, and there is also the chance to find a remote which has a socket to connect a common 3.5mm audio jack to shot and focus contacts.
I'm sure to have one of them, but I'm not sure where it is ;-) so I decided to DIM (do it myself!) an N3 plug.

I'm lucky to already have a compatible shutter remote (which I use for timelapses), this is necessary because we need obviously a reference to model our plug, and we don't want to flow resin into the camera socket, do we?

First we have to insert three short single core wires into the little holes. These wires would reveal the pins position in our mold, and would keep in place the cables meanwhile the resin hardens.
Bend the wires so that they will remain in the mould after the casting, I've also glued them together with some double component epoxy glue.
To avoid that the plug sticks to the cast you can cover it with some silicone grease.

To make the cast you've various options, I opted for a double components molding silicone rubber, which is handy because you can keep it for years in your drawer and it will always work. Of course you can also use the Sugru, which maybe has a better colour, I don't like pink, I prefere purple ;-)

After some time (sugru is faster, my silicone rubber needs some hours), you can keep out the plug. If things go right, the single core wires should stay attached on the cast. Check that the wires are in the right place and straight vertical.

To make the wires contact with the camera pins I've choosen to use some 2.54mm dupont female connectors (you can find some on eBay). At the first I wanted to wrap then into heat-shrinking tubes, but I realized that there is no place for that, anyway I didn't want that resin went into the connectors, so I decided to wrap them into a little piece of adhesive tape.

Insert all three connectors on the wires in the mold. Pay attention that all three should stay good in contact with the mold base, because we don't want the resin goes inside them from the bottom. So use thin pliers to put them in place. 
You can now flow the molding resin, or rubber. I've used black rubber because I wanted that the plug be some flexible, but liquid plastic is good enough.

After the need time, which could be some days too, remove the plug from the mold and check that everything is right. In my case, as you can see from the image, the result is rather awful, because I may got wrong in mixing the two components, there are a lot of air bubbles there.
Anyway... you can cut away some rubber in excess, and refine the plug so to wrap it into a piece of heat-shrinking tube.

Ready! Afters days of work your plug is ready to be soldered on your diy device! ;-) You can say that this is not worth the efforts... maybe, but a lot of instructables are made for the only pleasure to obtain an unusual outcome or take on a new challenge. I've also learnt something new about molding, which is an interesting big world.