It would only be right to start this thread with a picture of our inspiration (all credit to the Lift team as it truly is a stunning product):
May the discussions, builds and fun start!
Which torqeedo model is the gearbox for? And could you possibly give me dimensions for it?Bazaki wrote:I do have the 14:1 ism gearbox from torqeedo laying around and thought about a flier 420a esc and a TP 5860 or 70 motor,
But a good housing, i have no idea yet.
The only problem with a 100mm motor, is that is almost twice the drag of a 56mm. You'll also need a larger prop because of the drag. I think that the 56mm is maybe the ideal size.hardwiring wrote:Thanks @Jezza great start
I plan on a similar tack as yourself, great heads up on the windsurfer so thanx, but I am going to hunt out a low kv motor and tie it to an big 12s.
Alien power systems offer a 100mm custom KV, I can probably Ali up a supplier also.. GL all
Thanks, coming at this with Esk8 experience and I have not considered drag. In Esk8 there is an sweet spot of battery S to kv, very basically high s lower kv. Don't believe this is all about the ESC that we use but I am often wrong so assumed 10s 190kv , 12s sub 150kv .... that 14 to 1 box looks good, guess could be tough to find my side of the pond.Jezza wrote:
The only problem with a 100mm motor, is that is almost twice the drag of a 56mm. You'll also need a larger prop because of the drag. I think that the 56mm is maybe the ideal size.
How low do you want the KV?
Quote from Jezza, 6800 rpm prop speed? That is very high i think, torqeedo is using 1300 rpm and i believe that 2500 rpm is most efficiënt for most outboard props.Performance:
Max Power: 9.8 kW (205 A @ 46.7 V)
Max Speed: ca. 44 km/h (probably higher as max throttle was never applied for a longer time than 2s)
Max RPM (prop) : 6800 rpm
Planning speed: ca. 20-25 km/h
Power @ planning speed: ca. 3.2 kW
So from what I can see:Bazaki wrote:Quote from Jezza, 6800 rpm prop speed? That is very high i think, torqeedo is using 1300 rpm and i believe that 2500 rpm is most efficiënt for most outboard props.Performance:
Max Power: 9.8 kW (205 A @ 46.7 V)
Max Speed: ca. 44 km/h (probably higher as max throttle was never applied for a longer time than 2s)
Max RPM (prop) : 6800 rpm
Planning speed: ca. 20-25 km/h
Power @ planning speed: ca. 3.2 kW
1300 rpm at 5hp is 27nm of torque, the gearbox can handle 7,5nm and is also 75% efficiënt. So 25% in waist.
If you are UK based, torqeedo stuff is quite easy to get as its all based in Germany. The RC boat scene is also huge in Germany so that's where most of the parts will most likely come from.hardwiring wrote:Jezza wrote: Thanks, coming at this with Esk8 experience and I have not considered drag. In Esk8 there is an sweet spot of battery S to kv, very basically high s lower kv. Don't believe this is all about the ESC that we use but I am often wrong so assumed 10s 190kv , 12s sub 150kv .... that 14 to 1 box looks good, guess could be tough to find my side of the pond.
What S for 2000kv??
Good stuff. Watching you like a hawkmsk8 wrote:Hi all you DIY electric hydrofoil builders! Great that we have a thread for this now. I started a project too and am documenting it here: https://m.youtube.com/user/pacificmeister
Design is still changing a lot. I use Fusion 360 to model components and I am trying to 3D print most parts. I have a pretty powerful SSS54104 500kv motor, and just added a 7:1 planetary gearing from Parker. Brings my prop to about 2500rpm with a 10S setup. I'll start with a 13cm printed prop and see how that goes. I can later print different prop sizes / shapes and tune performance.
I plan to use a Liquid Force aluminum mast and will attach to my RRD K-race 70 kite race board which has been collecting dust in the garage. Will hollow the board and put batteries and ESC inside. Probably add a big aluminum plate as heat sink for cooling the ESC. My parts list is here: https://www.dropbox.com/s/d31ti8819uahm ... .xlsx?dl=0
Hope to get this in the water soon but there are still a few challenges ahead. I look forward to continue hearing what everyone else is doing and discovering. Aloha!
With an efficient foil, I think you can get away with a much smaller motor! I would suspect you could even use a max 4kW motor and it would work fine.Bazaki wrote:It takes about 11kw to get in plane and get good speeds with a normal surfboard like the lampuga. I recently bought a hydrofoil for kitesurfing and there is zo little but of power needed to get good speeds. I just imagine what speeds we will get when we let go the 11kw at a hydrofoil![]()
For years I have been trying many electric outboards etc and one of the things that i found out is that torqeedo is doing a great job, it doesnt even need watercooling. I have a 288rpm kv motor, will gear it down 8 times and put it in the casing of an old trolling motor. I will get about 1500 rpm prop speed. The torqeedo prop speed is 1300, and there prop seems to be very efficiënt. I only wonder when torqeedo prop speed is 1300. Under heavy load or free spinning
Have you ever had a bad fall waterskiing? I have and you can have a serious impact. Falling at 60kmh from a height of 1m above the sea will hurt like a mother $&*%$£!!Bazaki wrote:I know we can foil with less power,.thanks for posting details.
He goes about 30kmh at human power, but i wonder what speeds we will get with 11kw. A foil that can go 60 kmh is much more fun than 30kmh.
I also wonder how much watt we loose from the drag of the casing of the motor. Lets say 40kmh with 10cm diameter but with a sharp edgde
I will gladly eat it for breakfast lunch and dinner once I have one of theseJezza wrote:Have you ever had a bad fall waterskiing? I have and you can have a serious impact. Falling at 60kmh from a height of 1m above the sea will hurt like a mother $&*%$£!!Bazaki wrote:I know we can foil with less power,.thanks for posting details.
He goes about 30kmh at human power, but i wonder what speeds we will get with 11kw. A foil that can go 60 kmh is much more fun than 30kmh.
I also wonder how much watt we loose from the drag of the casing of the motor. Lets say 40kmh with 10cm diameter but with a sharp edgde
I think the most frustrating part of this project for me is by far trying to find gearboxes. I'd love to experiment with a complete budget build, but gearboxes seem pretty scarce in the UK (and very costly). I am debating whether an adjustable drill gearbox would work...
What motor is that? There's no link.eyebyesickle wrote:Jezza wrote:Bazaki wrote:I know we can foil with less power,.thanks for posting details.
I was just gonna strap this to a foil (with duct tape, of course):
Price :256 usd
Rated Speed: 1950 turns/minutes
Rated current/Amp:48A/24V
Decibel:50
Propeller:3 leaves/10.6 inch
Max speed:2500 meter/hour
Max power to propel:1000 KG
Suitable for:6-8 person
Power:1152W
KW:0.756
Propelling effort:1000KG
The motor is $250... the battery would be laying around... I will use a cheapo digital waterproof remote temp sensor temporarily... I am just trying to left myself up to motivate myself to sink (poor choice of words?) the rest ..... as an alternative if I am too lazy to pull a 'meister' (who is killing it, by the way):
Oh, tell me I am not the only one who was thinking of mounting this into a upside down jet drive on the bottom fin to increase lift! hahahaha. Better get that angle right
Jezza wrote:What motor is that? There's no link.eyebyesickle wrote:Jezza wrote:Bazaki wrote:I know we can foil with less power,.thanks for posting details.
I was just gonna strap this to a foil (with duct tape, of course):
Price :256 usd
Rated Speed: 1950 turns/minutes
Rated current/Amp:48A/24V
Decibel:50
Propeller:3 leaves/10.6 inch
Max speed:2500 meter/hour
Max power to propel:1000 KG
Suitable for:6-8 person
Power:1152W
KW:0.756
Propelling effort:1000KG
The motor is $250... the battery would be laying around... I will use a cheapo digital waterproof remote temp sensor temporarily... I am just trying to left myself up to motivate myself to sink (poor choice of words?) the rest ..... as an alternative if I am too lazy to pull a 'meister' (who is killing it, by the way):
Oh, tell me I am not the only one who was thinking of mounting this into a upside down jet drive on the bottom fin to increase lift! hahahaha. Better get that angle right
There isn't any point in mounting anything vertically. A hydrofoil naturally provides lift once its moving at the correct speed.
There's no doubt about it in my mind that high voltage (HV) and low current makes sense! Just from a battery life point of view it makes all the sense in the world.dirkdiggler wrote:I was looking into using an EDF last night. You can get one for $150 that does 4kw. I don't know how those will do in water though. Would a 5 fan blade be better than a 12 fan? I think with a foil it might be better to run high voltage and use an ebike controller. That way the amps are much, much lower. My e-kayak attempts made all my batteries puff as the motor drew such high amps. Recumpence stated on his build that he needed 7500w and blew a couple expensive Castle creations controllers trying to get it worked out. Granted a foil is much more efficient.
Anyhow, I'm going to try and get my e-kayak out again and try running it at 72v with an ebike controller. We'll see if its any better.
I'll try an EDF when I finally learn how to foil.