Guldsteen’s build - CAD, links and pictures

Hi everyone

I have been collecting parts for my build over the last 10 months and has finally ordered the last parts to be able to finish my build. Therefore I want to share my final bill of materials and share my CAD design of the propulsion unit. I will be updating this post, as I progress with my build and you are more than welcome to comment on the parts! :slight_smile:

Motor - SSS56104 500Kv
Gear - PLE40 5:1
Prop - MaB design, Pitch = 215 (printed in PC covered with glassfiber or carbon)
Batteries - 4x Multistar 6S 12.000mAh 10C (Total = 12S 24.000 mAh)
ESC - Flipsky 200A FSESC waterproof
Foil - Naish Thrust WS1 w. 70cm mast (Windsurf foil, 1200cm2)
Remote - Flysky FS-GT2B (waiting for new Flipsky waterproof remote)
Board - Starboard iSonic 111L (235x68cm, maybe cut to 175cm when I get comfortable)
Case - PELI 1400 Small Case IP67
Antispark - Flipsky 280A Antispark Switch Pro
Cables - 8 AWG silicone, 200C
Miscellaneous - 150A Circuit breaker, voltage/amp meter, 12V water pump,

Electrical diagram:

CAD files of propulsion unit:

Photos of build progress:


Hi good job ! One New cao design i have to explore …shaft coupling etc .
Thanks for the sharing on the forum because …i love to see motor who was fixed to the Gear box and to the tube…why did you don’t use CNC part for all the propulsion unit , if you Can ? It will be better for the ampli…
How many Time to draw all this fusion 360 unit ?
So i just finish m’y board and i have all part to finish the build just have to decid what cao design i prefer and of course the cost for the CNC machining,
i have access to a metal lathe si i Can Do some part but not all…and nice naish foil you have✌️

Hey sniper. Thanks!
The reason for not using CNC only parts is, that I have limited access to a CNC lathe, via a colleague, but unlimited access to a 3D printer. I have identified two very strong FDM filaments, Polymax PLA and Polymax PC-Max. When printing 100% with wall lines and no infill, the parts become insanely strong. I then coat the outside with epoxy for waterproofing.
The propulsion unit design is derived from Pacificmeister´s build, but improved with better coupling, better bearings and three lips seals, two between the bearings.
I also designed the duct as a Rice-nozzle, for better efficiency at higher speeds, hopefully, but not tested yet.
It is designed i PTC Creo, which I have access to through my work - I am a mechanical engineer.


Would you show us the airfoil section of the duct ?

Im not sure what you are asking for, Can you specify?

I meant, how does a Rice-speed nozzle look like ?


I have designed the Rice speed duct from What I Could derive from this website: Link


The 23+ years old 1997 Rice speed nozzle patent is very boat oriented Method of making a Rice speed nozzle . Therefore, there isn’t much information for an efoil use, except a clear view of the Rice speed nozzle shape plus one interesting detail :

To obtain the best performance out of the marine speed nozzle, the blade tip clearance between the interior shell portion 20 and a tip of the propeller 80 will be equivalent to about 0.4% of a diameter of the propeller 80,

So for a 140mm diameter propeller, this represents a 0.56mm clearance between each rotating blade tip and the duct inner surface… not much then :neutral_face:

Yea, it has to be tight, about the thickness of 5 pcs. of ordinary printning paper.

Goodmorning. I have updated the duct some, both a more tight fit to the propellers and a more representing profile of the Rice speed duct:

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ok thanks .but what you do at 100% if you do in no infill? yes the pc max is my new filament i love it just need to test it with 0,6 or 0,8 nozzle to reduc printing time and have a larger line and a better hall …you new iteration of the duct gard have loose the insert for the rear protec…forgotten?..i see 2 little hole in the part who cover the gear box and the coupling part what are they? for tightening or control the coupling screws…? i just need to a list of all the bearing and the joint what you use because you ve got lot of parts in the conception :smile:

So, instead of having e.g. 5 walllines (5 x 0.33mm) and then infill, i use up to 30 walllines, filing the part completely with no Air pockets, this makes it very strong.

Yes, the two holes are to tigthening the coupling between motor and gear, and between the gear and propeller axle.

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Have you tested this version of the duct vs unducted in real life?

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