Earmuff's Nozzle's pads costruction process...

Look at the nozzle pads.

This detail, has been a real nightmare to reproduce. In fact this object :

1) is thin (triangular rims)

2) has curved (arc-sectored) shaped areas

3) the rims inside are placed in curved shape

Here I'll show some of the tentatives I did:

 

Glueing Rims and spacers...       Cutting and filing....

 

Yes, I did ONE, But the others...? all different??       Test put together to see the (horrible) result !!!

 

In the images I cut some styrene arc pieces, and directly glued small rims inside (pieces of styrene strips 1x0,5 mm).

using spacers, to have them with the very same step.

The result has stopped me to further proceeding this way: Each pad would result to be different from the other!!!!.

This is horrible and was unacceptable for me. Then I tried another way.

A friend of mine, has a very precise pantograph. The only thing to build was a scaled-up track on plastic guide 2 to 1.

Using compasses and a scribing tool, realized this (top):

 

Pantograph scribed plastic (in two deep)

 

In the upper, you can see the plastic guide: a scribed piece of plastic twice the size needed. 

With this original, I pantographed the two master molds can below. This plastic piece is cyanoacrilate.

I used it (squeezing inside RTV rubber) to get the NEGATIVE of the mold needed.

 

 

Squeecasting the negative...

 

Then I used this second mold (pink RTV) to pour the pieces in white ceramics:

to obtain it's negative. I poured ceramic (same used for earmuff's domes).

The result can be seen here:

 Complete Earmuff's pad costruction process

 

next step: put everithing together to assemble earmuff!!!