375/6075 Yellow Castle's helmet Reproduction project started

Hi everyone! I am Ken of smilebrick.com.
If you are a LEGO user, Wish to try making original LEGO.
As a first step, I am planning to challenge the Reproduction of the retractable helmet covered by the knight of Yellow Castle 375/6075 Mini-figures born in 1978.

What kind of thing is it?

This is a helmet with a hole in the visor part in the T shape like this.
In Japan was not released at that time, it was a mini figure included in the set of yellow castle that I long wanted.
I have been searching since I was a kid and I found it and purchased it overseas at the auction site about 10 years ago.

In this set, one figure of a knight who wore red, white, ash, black visor was contained one by one.
The catalog at that time was not a gray visor but also a blue visor knight was photographed.
The illusionary blue visor is so cool!!

When reprinting, I also considered 3D printers. But i abandoned it.
Because it turned out that even with a 3D model printer of precision shaping which is increasing in precision, it can only produce precision of about 1/100 mm.
Lego's molding precision is really 1/1000 mm!
In particular, the accuracy of the head, neck, torso and legs of a mini figure is spectacular.

Then, how big is 1/100 mm?
If you look closely at LEGO you may see the parting line of the mold.
The height at which the gap of this joint is caught by the nail is about 1/100 mm.
It is a level that you can see enough with human eyes.
I think that the roughness of the surface which can be done with a 3D modeling printer is approximately 1/100 mm.
In parts made in China, this parting line gap is large, the parts and parts are loose, and it is too tight.
This is a problem that can be made when shaping without expectation of shrinkage, warping, shrinkage ratio due to insufficient molding precision or the properties of ABS, polypropylene, polycarbonate and other materials.

if possible, I would like to make molds, exactly fit with Lego, perfectly combine them, and make it with molding accuracy equal to or higher than that at the time of sale.
I would like to make non-original colors. For example, blue or chrome color.
(The test sample has already been shown in the thumbnail...)

At the time of reprint, there are so many problems.
So, I would like to report on the problems until we overcome these problems little by little and reprint.

next part : Factory tour until Lego's Reprint Helmet is molded(1)