Very slow build from France


#121

Man, that’s sad. Sorry to hear that. Did your ESC survive?

I need to take a break as well because all my 3d printed parts (PLA) of my pod melted inside my car because of the climate change :wink:


#122

Do not know yet for the esc but probably , i was riding , got something in the propeller , fall off , when i tried again , motor unscrew and than nothing , this Time i stop , cut off everything and swim back …


#123

may be save for part , shaft and pignon but doesn’t smell nice…


#124

Very sorry to see this mess!
How did you fixed the motor? I’ve not clear the dynamic of this disaster: the motor was tightened to the end of the pod but got lose and rotated inside the tube? But how the cables stripped or melted up to short circuit?


#125

whooooo really sorry, how did it happen that the engine spins on itself in the aluminum tube


#126

the motor has a flange (4screws) , the chief gearbox is screw on the flange, the gearbox is fixed on the mount on the tube
the cables for the motor are fixed on the mast mount

with a right hand propeller: the propeller shaft can unscrew from the gearbox (happen the second run)
with a left hand propeller the one i am using now, that the motor flange that can unscrew from the gearbox

my fault i did not think about that, i did not use loctite

the motor spined on itseft in the tube as the propeller probably go cut in weed

the 3wires made one twist (on the pics i un twist them to look at the disaster)

so one big twist, burn the covering and the windings inside the can, the plugs melted

pic from silvio setup (if you don’t mind) , flange with the motor that unscrew from the gearbox

http://efoil.builders/uploads/default/original/2X/1/1056b977ed4cf7fbc6e2cec41605b32d8a15e6a9.jpg


#127

Thank you for the feedback! I missed that the Reisenauer flange is screwed into the gearbox body.
Probably, threads washed with Acetone and green Loctite, your pod would have been ok.
I missed also that you’ve the motor cables with connectors, not soldered directly to cables coming from the foil mast. Motor rotor seems ok, you can just swap that on the new motor and be ready to hit the water in no time!


#128

exactly! but i don’t have the new motor with me (2H drive away) and i am going in vacation in 2 days for 3weeks, (planning to do 2-3 runs before but no)

one wire was unpluged , that is what probably save the esc…

i guess i just will see my oestopath, so he can fix my back after many falls…


#129

thank you for this return, and happy holidays anyway.


#130

Sorry to read that Alexandre. What was your ESC brake set on ? ON or OFF ?

"OFF " with an RR prop may prevent the shaft from unscrewing, but you would definitely need a duct for obvious safety reasons.


#131

Boat esc no reverse no brake set everything on soft , weed will get stuck no matter what i will do, i ma working on a duct :wink:


#133

Back from vacation… Try to foil this week… I took a part the old motor , put the rotor with pignon in new the can , took apart the gearbox to heat it up and unscrew the glued shaft

inside the chief gearbox :smile:

It is press fit , so it is in the fridge right now…


#134

press fit nothing… domage the main bearing, push the 4 gears holders to far, broke the clips and started to cry

if you take the gearbox a part you need to take every a part in order to press the main bearing correctly, no short cut…

any way this week i manage to put everything back in place : reduce the diameter of the gear holder from 15.05 to 15.00, fit the bearing without pressing to hard

i find the 4mm e-clip to hold the 4 gears (not easy to put back)

the main bearing : https://www.123roulement.com/roulement-3002-ZZ-INA.php

ready to fly again …


#135

Nice day nice water , 20 min ras , very happy , alone , but i will try to make some video tomorrow , cannot wait to see the log with the new motor 860kv …

Did not loose any skills during 6 weeks :sweat_smile:


#136

So new motor more kv same rpm about 3100 just more amp , will see too speed tomorrow , foiling between 100-130A with 8s , don’t really understand why … I guess that is the max of A 40mm motor …
I will work on the new board for the moment and go with a 56mm and 12s after …


#137

Well, more KV means less KM means less torque/A, so you need more A for same torque, and Torque per RPM is determined by the propeller (in combination with drag, weight etc.). So if you have the exact same setup but more KV motor, your amps have to rise to get the same RPM (since you still need the same torque for your propeller to spin at this certain RPM, and thus more KV means at less torque/amp the amps must rise…).
So I would try to either cut the prop (less torque needed for same RPM, and also higher RPMs possible due to more KV motor, this also might give more slip so maybe not that good efficiency) or adjust propeller pitch (maybe even in combination with diameter…also less torque needed but hard to find the sweet spot…).


#138

You’ll bring down the current if you increase the voltage. Go to either 10s or 12s if your motor can handle it.


#139

thank you

yes i will go 12S
yes i already tried to size down propeller

i am happy with this set up, i used the 860kv because i have it (not the best choice apparently)

i try the solas plastic propeller, reshape it (work), just cut it (work) but i was not able to get more rpm and more speed (20KM/H)

i am using right now the FR propeller, i will not cut it, it is to beautifull !
i want from 20 to more than 30km/h with it
this propeller is well made and has the correct thrust for foiling i think , as i go above water, speed will increase by 80-100%, no need for more thrust…

so i change KV, propeller and it is always 3100rpm on load, i could try a 550KV on 12S by i think i will be better of using a 56mm

or keep the 40mm and change the foil with a “race wing”…

it is interresting to see that there is a correct kv to use, in my test going from 780KV to 860 i haven’t got more rpm, just more amp and about + 10°c on the ESC

i think i maxed out the torque on this 40mm motor for my use


#140

Hi
I’m building something like yours with a 56 engine (sss 390kv , 14s) and the same gearbox 5:1
Can you share a link for the FR propeller ?
Thanks


#141

I’d just put 12s on the small motor and see what happens. I’m sure you get more power and more speed out of it
I tried my setup (750kv) with 8s, 10s and 12s. 12s made an incredibly huge difference! Much more power and thrust with lower current.