SUP Propeller

This is an easy-to-build power fin for HF stand-up paddles.
 

Test Video:

Here is a list of the main components needed:

Waterproof box:

https://de.aliexpress.com/item/1005003311346853.html?spm=a2g0o.order_list.order_list_main.127.58e55c5fC9i4Yw&gatewayAdapt=glo2deu

ESCs: 
https://de.aliexpress.com/item/1005006256693706.html?spm=a2g0o.order_list.order_list_main.132.58e55c5fC9i4Yw&gatewayAdapt=glo2deu

Motors:

https://de.aliexpress.com/item/1005006400921154.html?spm=a2g0o.order_list.order_list_main.142.58e55c5fC9i4Yw&gatewayAdapt=glo2deu

Servo Tester as Speed Controller: 

https://de.aliexpress.com/item/1005005968874476.html?spm=a2g0o.order_list.order_list_main.158.58e55c5fC9i4Yw&gatewayAdapt=glo2deu

PG9:

https://de.aliexpress.com/item/32981045114.html?spm=a2g0o.productlist.main.1.4be43d88G2zZn7&algo_pvid=0c4049a3-39a3-49c8-8510-591f6ea5862b&algo_exp_id=0c4049a3-39a3-49c8-8510-591f6ea5862b-0&pdp_npi=4%40dis%21EUR%211.79%211.79%21%21%211.91%211.91%21%40211b617b17228435019905718eeb28%2166850904008%21sea%21AT%21856809352%21X&curPageLogUid=ZBtOAaixWDkE&utparam-url=scene%3Asearch%7Cquery_from%3A

cables: (flexible silicone wire) 
https://www.pollin.at/p/rautronic-silikon-leitung-sihf-j-3x-1-5-mm2-10-m-561810

Battery: 

i made a Battery out of 24x 18650 cells (6S4P) 
Any 6S Lipo battery should work as long as the rated discharge current is sufficent (~20A) 

Printing:

The parts are printed with Bambu PETG on an X1C. The propellers have extreme overhangs, so place them near the aux fan and set the aux fan to 100%. The Propeller blades don't need supports!
 

The motor contacts need to be soldered and sealed with some silicone or similar adhesive. 

If the motor spins in the wrong direction, just swap any two wires. I recommend to put some connectors between the ESC wires and the main wires for an easy swap. 

I tested a lot of different propellers, a two bladed 80mm prop turned out to be the best solution for printability and thrust. 

Each prop puts out a thrust of 2.6kg drawing around 180-185W of power. 

The tests were conducted with this shown test-rig. Current, RPM, thrust and battery voltage are measured by an arduino across the entire power range. 

The wires run through the main fin body. 

The motor fin works for this clip mechanism. make sure it works for your type of SUP board before purchaseing the design. 

This is my SUP board…

Have fun! :)