The original silicone mask that was made for the InMoov head was far too inflexible! I used the wrong silicone rubber …

I am creating a new face for the robot head as the original silicone face mask was far too stiff and not flexible enough. I had used 00-20 two-part silicone moulding rubber, and although quite flexible, it is just a little too stiff for the servo motors used in the robot head. As the servos are pretty cheap and not particularly powerful, the silicone used in the first mask is too stiff to allow for much movement or facial expression. So I have just bought some 00-10 super soft silicone moulding rubber in the hope that it will be flexible enough for the full range of facial expressions that the face should be able to make.

A new mould has been printed for the robot face (a female version this time), as the original mould was partially damaged when the silicone face was being removed. The mould parts were sprayed with a silicone release agent, but the inner parts of the mould would not detach and it had to be broken apart to remove the mask. Hence, a new mould has been 3D printed and is shown below:

The filler that can be seen on the inside of the mould is to stop the silicone from leaking through. It also helps to provide a seamless mask.

The inner centre mould part has also been reprinted, as that was completely destroyed to remove the original mask. The new part is shown below sandwiched between the left and right inner moulds. The inner mould is in three parts for ease (!) of removal.