First, thanks so much to all who are sharing there info on their boards. It’s a tremendous help!
Problem: My motor won’t spin nearly fast enough to get me going. Even without me on the board, the board barely goes 2 mph. Outside of the water, the motor spins at normal rate for it’s kv and voltage (at least I assume, I don’t have a data logger). If the prop is half way in the water, it also spins at normal rate. The prop 90% in the water, same thing. As soon as I put the prop all the way in the water, the speed drops dramatically, to about 5% of what it was. From what I can figure, when the prop is fully wetted the current spikes and the ESC compensates by slowing it way down. Maybe something in the ESC programming, or propeller? Or maybe the phase wire connections inside the mast? I can’t figure it out.
ESC: Alien Power Systems 300A 12s Boat, with water cooling
Motor: Custom 160kv, 65mm inrunner (max continuous current = 95A), water proofed, motor contacts water for direct water cooling. I also have a 109kv, 65mm, 70A inrunner that I will be testing soon.
Battery: Homemade 12s8p Lithium-Ion, Samsung 25R cells
Propeller: 3D printed, 7 inch pitch, 6.5 inch diameter.
I’ve invested a lot in this and it’s not working. Very frustrating. The weird thing is that I threw together some spare hobby stuff I had a few months ago, lots of machined aluminum, duct tape, bad shaft couplers, etc, and it worked well enough to get flight. I used a 149kv outrunner motor that eventually overheated though.
Thoughts? I’ll try out the lower kv motor as soon as I can, and play around with ESC programming. Beyond that, I am clueless.