3) Flesh


Laser cutter

Download the lens.dxf file and laser cut the lens from a 3mm thick acrylic sheet, without removing the acrylic's protective film. The edge of the lens will be tapered slightly from the laser cutting process, with one side having a slightly smaller diameter than the other. This side will be pressed into the tip first , and is considered to be the bottom part of the lens. 

Lens cover removal Remove the protective film from the bottom part of the lens, and begin removing the top layer, leaving a flap for easy removal later.

Apply Loctite glue around the inside lip of the  tip.Spread the glue thinly to avoid it contaminating the lens.

Press the lens into the tip with its small diameter downwards, ensuring it has been pushed all the way down to the lip, and hold until the glue dries.

Apply a small amount of glue around the edge of the lens to complete the seal. Finish removing the top layer of protective film (tweezers can help for this step).

Silicone gel

Measure out 15g of RTV27905 part A in a plastic cup. Pour 15g of RTV27905 part B in the same cup. Mix the 2 components together vigorously.
Silicon gel part A Silicon gel part B Mix silicon gel components
Vacuum chamber

Place the mixture in a vacuum chamber for 5-10 min to eliminate bubbles. 

Note that if you are able to mix the 2 components of the gel within the vacuum chamber, this will result in less air being trapped in the gel. 

Insert the needle into the hole in the side of the tip. Have some kitchen roll ready in case the gel leaks. Fill the syringe with gel, and wipe it down with kitchen roll to avoid gel coating the outside of the tip.

Push the syringe into the needle and fill the tip with gel, angling it so that bubbles can escape through the air hole in the tip.

Fill syringe with silicon gel Filling gel with a syringe

 Once the tip is filled with gel, remove the syringe and plug the hole with the 3d-printed plug.

Finally, leave to cure for a minimum of 48 hours (if available in an oven at 40 degrees celsius.

Oven curing