Hi, I want to make an electric surfboard that I have the opportunity to upgrade to hydrofoil. therefore I want to use flipsky’s FS65161 120KV motor instead of water jet. i find no one who has tried this before, can it work?
I plan to use the makerx GO-FOC HI200 esc, and make the battery myself (samsung 35e 16s 3kwh). I have experience with this
I live in Norway
Hi, you might want to move this question to the newbie question thread as well.
Not sure I understand your question.
Jets operates at higher rpm than propellers. The larger the propeller the higher the needed torque (mechanically you should consider this as a mass to move. The mass is here the water). Which basically means if you go jet, you will be using higher rpm and less torque, hence smaller motors for most of the time because torque is directly linked to the motor’s copper mass.
For exemple you can use a 56114 motor with high kv for a jet application. But same motor won’t work for a 140-150mm propeller, and vice versa. A 65161 motor with 120kv will work with a propeller but won’t work properly with a jet.
Hi, I did not notice that there are several categories to post the question on. What I was wondering was if anyone has any thoughts on using a propeller (flipsky FS65161 120KV with propeller) on an electric surfboard (not hydrofoil)
You may be referring to something similar to waterwolfs boards maybe ?
https://www.waterwolf.de/de/boards.html
Basically a surfboard with a big propeller on it. I haven’t checked the motor so I can’t comment on it sorry.
Hi, your question is highly relevant and I think manye efoils have given it a thought.
Myself I built 2 jetboards back in the day using 64mm units MHZ/Onean. Even if the battery/esc/motor could push >10kw I could never get the boards planing with my 100kg, since the torque was not there.
I think this could actually work fairly well using the waterwolf setup and 6kw 65161 motor since torque should be sufficient. However the power will only be enought to reach ca 30kmh.
FR has a ready to use kit based on the somewhat larger Lift motor.
Please report back once you’ve tried
Sad that other makers such as Lampuga, Torque, Radinn and Ewave don’t sell individual spare parts too. This would be awesome.
Are Lampuga boards still active by the way ? Haven’t seen any of their products for years…
what is your goal?
are you looking to ride waves with this board (not sure if there are waves in norway?)
are you looking to stand up on it when there are no waves?
if you are looking to ride waves with it and use the motor as an assist, my input would be to go AS LIGHT AS POSSIBLE.
i built a jet longboard and it’s super heavy with a 12s12p lion battery and a kedean jet.
my next board will be a 6384 with folding prop and 4 or 6s battery
the prop is dangerous so still working out design.
in summary: DONT DO JETS. going from 0-> fast on an impeller sucks. maybe if you weigh next to nothing it could work.
All relevant high performorming jetboards use >100mm impeller size nowadays.
I live close to the testing grounds of both Radinn and Awake and especially the latter has a fanstically nice 120mm impeller carbon setup and can push close to 20kw for early planing. But sure, 15mins ridetime on 25kg battery is quite limted in time/range.
Most days I think I would prefer an efoil…
cim what about dual impellers?
i looked into dual jets but given my limited access to parts and limited skill, getting props and motors for props was way easier.
Inline or side by side? I never tested but Onean seems to get medium performance from their dual 64mm setups. Could absolutely be one way to ge to downsize motors and esc:s.
either. whatever would produce the best thrust:weight ratio
i forget the guy everyone knows who builds his own jets. he has a youtube channel and he built a little jet boat with side by side jets and it looks like the thing rips.
Yes a Swedish youngster. Yes it’s very similar to an onean setup, but with the English 3D printed 53mm youngsterjets. Would still go for Oneans system as they sell spareparts at good price and have a proven system for 5kw per jet.
Geez, couldn’t said it better ! I’ve seen Jetsurf’s facility and can confirm they are above 110mm diameter as well. This thing had a thrust of more than 100kg, tried to hold it with my bare hands so can definitely confirm this is impossible 
the onean twin board+battery is 34kg. might be good for cruising on flat water but I wouldn’t try to ride waves with it.
none of the commercial “electric surfboards” are made for riding waves. look at the shape of the boards. They are all designed for racing around on flat water. look at the rails and the rocker. geez.
I might be in the niche category here but I am building EPS core electric boards that can actually be ridden and maneuvered on waves. the shape of the board (and it’s weight) matter a great deal. I want to be able to do a top turn on a 6ft wave. and then use the motor to boost over the waves (or to assist duck diving)
thanks for the answers. My goal is to use the board on calm water, not surf on waves. It seems like there are many benefits to having a hydrofoil as opposed to an electric surfboard, so I might make a hydrofoil insted. Part of the reason I did not want to make a hydrofoil was that it can be a problem to approach and get ashore on islands when the hydrofoil goes far below the board. (we have many islands that I am often on in the summer where I live) I am now considering mounting the hydrofoil so it is possible to pull it straight up true the board when I go to islands.
I have looked at gong’s hydrofoils, but am not sure which one suits me. I’m looking for one that costs around 300-400 euros, is easy to drive and efficient through the water (wh per km) top speed is not important, it does not have to go faster than 35 km / h, but it’s no problem if it does. I remind you that I am thinking of using flipsky’s FS65161 120kv motor and makerx’s GO-FOC HI200 esc. the battery I wil make myself and is going to be 3 kwh 16s. I weigh 70kg
the battery I wil make myself and is going to be 3 kwh 16s.
In a previous thread it was mentioned that it is better to stick to 12-13S in case something goes wrong (electrocution risk). I have no experience on this, but please have a look to be sure
What motors are used or would you suggest for impellers >100mm? What RPM and power is needed for such a big impeller?
ok just woke up and i’ve’d the first-sip-of-coffee-crackpot-idea:
Could you use one ESC to control:
A) a propeller to go from 0->40 and then turn it off and switch to
B) an impeller to cruise at 40?
if cost wasn’t a factor would it be worth the extra weight of the second motor given how much more efficient impellers are at cruising?
I like this out of the box thread. For your idea, I am not sure if the transition from one motor to the other is as smooth as it should. Also it sounds very complicated to build; in my experience complicated setups tend to fail more often.
I actually had a late-shower-reflecting-life-decissions-idea in similar direction. How about putting a really small mast below a windsurfer with a small wing in the middle and the 120kv motor below the wing. The wing will just generate a little bit of lift so you have easier gliding. Maybe like a small kite wing. But no flying. Maybe stupid idea, but so am I
Cheers
