Help me diagnose my problem(s)

Just took the motor pod apart since it wasn’t acting normal in the video I posted above. Alas, lots of water in there. Really not sure how, I use 2 o-rings in the front, petroleum jelly inside, silicone outside, then a layer of flex seal like tape. The wall between the mast clamp and the pipe I’ve tested to make sure is waterproof and it has a layer of silicone on top of it too.

The back of the motor pod I packed the inside of the gearbox sealmount with tons of petroleum jelly. Double lip seals, ceramic bearing. Very little vibration. Not sure what else I can do to accommodate this damn thing! Ha.

Lets hope you haven’t shorted and blown the ESC as well.
I used aluminium parts instead of 3D printing to guarantee that my motor remained dry.
Before I sealed my old unit up, I used compressed air (my mouth blowing into it) to make sure all the seals were tight. This is probably why you couldn’t get full throttle!

Oops…had you done static tests like a full night in a water basin…but there’s a good chance the problem is coming from there. Maybe a lot of oscillations on the axis of the propeller…

I wish I had aluminum parts! Although I have access to a lathe, I’ve never used it before. So not an option for me.

I have done tests in a tub and it passed with flying colors. But I’ve also taken it apart a few times since then though.

For the water in the tube, i would say it again but i run my setup in a tube that was full of water by the end most of the time , i had just carefull waterproofed the motor connectors and solder with tape and shrinking tape : no problem , just like a outrunner setup

…just some thoughts…if you still don’t find the reason, you could try to get pulled by a motorboat and see if/how it can fly…in this way you could also check the power you need to get out of the water…just to avoid hydrodynamic limits and focus on propulsion system…

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I’ve been through the same problems.
For me, 3 main reason can explain your problem:

  • What size is your board ? If you weight 200lbs, you’ll need a pretty big board in order to achieve the take off speed of your foil (for most "big foils around 6knots). This means something near 130L and pretty long. This way, you’ll lower the power needed to get on the foil

  • I’ve tested out many props, included the 4 bladed prop from Pacificmeister and it was the less powerful one (the one recommanded by virus worked just fine). Also, PacificMeister is using a 5:1 gearbox, which means around 100kV equivalent in Direct Drive Setup. With your 500kV and 7:1 gearbox, you are closer to 70 kV --> Your propeller is not spinning as fast as PM --> Less thrust --> Less speed.

  • As Virus said, you want the board to be as flat as possible to reduce the hydrodynamic drag of the board when in archimedian mode. This means standing more on the front of the board.

You are pretty close indeed, few changes should make you fly soon !

Also: I ran my 80100 fully submerged in the water without any problem !

Me too, i replace all PLA parts with Al 6061 and send them to machining shop. Also i add a double bearing on the shaft to be really aligned.

My solution was to abandon the gearbox setup! Ha. Maybe one day I’ll revisit just to say I did it but man, water is a tricky situation!