So, after around two month i continue my work in CAD and did some testprints. PEr example if my Mastclamp fits to my 63100 motor.
Here a pic of all what i do.
and my testprint
Inside my Box i have a lot of work to construckt. I will seperate it in 3 areas. (Batteries, Elextronic and on save closed box that stops when water coming inside my mastconnector)
… and here the other side on my technik box.
… here my mastclamp with duct.
The duct i decide to mount on the Fuselage. After printing in 3D i will coat it with CFK. I hope it is strong enough, when not i can easy change it with a more stronger model.
So, I bought the Flipsky 120kV Motor and change my CAD constructions to that system.
Here is my Fusion 360 CAD.
I decide to print first the Duct in PLA.
I want use the same colorscheme from my Gong Foil. I think the colors are very similar 
Very interesting. We could imagine that the front section of this square shape could have the same section as one half NACA airfoil section to minimize drag.
You do not need a grid at the downstream side, only upstream is important, because the propeller will repell anything which comes from the backside without danger. Only if you plan to spin the motor backwards it makes sense to have a grid at the back. Also the grid at the front side is too wide to protect the feet properly.
At moment I print my Duct without a grid!
The grid I want only when my children riding my efoil. I am working for some details for save my children. So it should not possible to start the Motor when a magnet is mount over an Reedswitch.
The grid should me only that nobody push the hands into the Propeller from the back. You are right, the front part is not save but I hope some one not put the hands complicate from the front to the running Propeller 
So, the next part is printed.
I calculated the Prob Online with that link.
After theme I downloaded the Cad File and import it in my Fusion 360 and made mu constructions.
The result is a nice Propeller that fit exactly on the shaft from my motor.
Wait, you are printing without supports and still getting that quality ?
I would 100% fail I think
Yes, but on the underside i have not so a nice surface. But absolute no problem because I can clean that with a file.
Can I ask how much did you pay for this board ?
It seems a good shape and hole looks great too !
It was a prototyp, i payed 400.- for it.
The company is a Startup, based in CZ.
The boards for selling from theme, made in Carbon costs around 800.-
I also use the Anycubic Chiron. It’s a good printer. But I made a few modifications, which improved the print image even more.
On your propeller I also see potential for quality optimization with the right settings.
Overhangs up to 65° are possible without support.
The blades look thin, I suspect they will break. I have had a good experience with my impellers with a blade thickness of 3.5mm and PLA pro.
PLA pro can be post annealed in the oven. It is then harder than ABS. And very easy to print.
So, Mastclamp is finished printed.
I use 1,5mm wall thickness and 0% infill.
I will fill it wish Epoxy and 3mm Glas
So, I use the chance and get one of the last FR Props. So, will be interesting how big ist the difference between my DIY Propeller and the FR Propeller.
Tip for your next prints: If you use a 0.4mm nozzle and the layer width is set to 0.4 in your slicer, the wall thickness of your part should be dividable by the layer width. (1.5mm /0.4 will result in 3 layer and some gaps between the walls. 1.6 mm / 0.4 gives four walls and no gaps.) So you get better print results and well connected layers. Wherever possible, it is best to take into account during CAD design that all walls can be divided by the layer width.
