ropower86
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Where are you standing now with your project? 
Electric Surf Board
- Thread starter Matthias_S
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Bazaki said:Everybody moved to the efoil builders forumso many are already riding there electric hydrofoils
link?
fabianpusch
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https://efoil.builders/
Here it is...
But they are really focused on Foilboards.
But still interesting....
At ropower any test rides done yet?
Looks short, really short.
I am interested about the feedback.
Here it is...
But they are really focused on Foilboards.
But still interesting....
At ropower any test rides done yet?
Looks short, really short.
I am interested about the feedback.
I did some progress and now only wait for vacation to do some water tests.
I especially modified my batteries. Now running on 48 pcs 20700 liion cells, 12S4P. Each parallel pack with own 60A BMS.
I also build a power distribution board, where I put in all battery packs and charger (for charging all of them simultaneously. It has a display with voltmeter, a hall sensor for current measurement and 8 additional capacitors.
I especially modified my batteries. Now running on 48 pcs 20700 liion cells, 12S4P. Each parallel pack with own 60A BMS.
I also build a power distribution board, where I put in all battery packs and charger (for charging all of them simultaneously. It has a display with voltmeter, a hall sensor for current measurement and 8 additional capacitors.
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chris_kline
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I spent a year messing around with my jetboard, but every time i took it out, there would be some electrical problem. the esc kept blowing the caps, mgm are literally the wors company to deal with from a customer care perspective.
i made external caps banks, which helped, and made an additional watercooled heat exchanger for the esc, which helped again.
by now my batteries have been cycled around 50 times, and im starting to loose individual cells, so the packs need to be pulled apart and cells individually checked.
heres a video of the last run i did on new years eve https://www.youtube.com/watch?v=QnzaSyVcLh4&feature=youtu.be
i made external caps banks, which helped, and made an additional watercooled heat exchanger for the esc, which helped again.
by now my batteries have been cycled around 50 times, and im starting to loose individual cells, so the packs need to be pulled apart and cells individually checked.
heres a video of the last run i did on new years eve https://www.youtube.com/watch?v=QnzaSyVcLh4&feature=youtu.be
chris_kline
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eventually i got so sick of the problems with the esc, mgm, and the cells, that i built a gas jetboard from a 2 stroke racing kart engine.
i know this is an electric power forum, but i hope you dont mind me posting a couple photos and video of the second jetboard i made.
here it is part way through construction
i know this is an electric power forum, but i hope you dont mind me posting a couple photos and video of the second jetboard i made.
here it is part way through construction
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chris_kline
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heres a video in action https://www.youtube.com/watch?v=SbtyIEKx-kM&feature=youtu.be
chris_kline
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yeah, well they must have figured out a way to stop them exploding.
maybe they went with external watercooled caps banks also, or maybe they just tuned the resonance out of the caps with specific wire lengths and battery configs, and esc settings.
through a combination of increased motor timing to max, a large external watercooled caps bank, and temp monitoring, i managed to stop the caps exploding in the end. but mgm were literally useless, they had no tech insight to offer, rarely replied to my emails, and refused to offer any kind of warranty, despite the claims that their esc's are guaranteed.
even the chinese companies i bought esc's from had way better customer service than MGM.
maybe they went with external watercooled caps banks also, or maybe they just tuned the resonance out of the caps with specific wire lengths and battery configs, and esc settings.
through a combination of increased motor timing to max, a large external watercooled caps bank, and temp monitoring, i managed to stop the caps exploding in the end. but mgm were literally useless, they had no tech insight to offer, rarely replied to my emails, and refused to offer any kind of warranty, despite the claims that their esc's are guaranteed.
even the chinese companies i bought esc's from had way better customer service than MGM.
chris_kline said:
I personally saw two of the old Lampuga surf boards opened and there was anything like that
chris_kline said:
This is very bad and useful info about MGM.
Did you noticed the bike controller that Vasilisk is developing? I thought the 24 fets with a Maximum power of 20kW and a Nominal power of 10kW could be good to drive a surf board out-runner motor. What do you think about it?
They also can be potted to protect them from corrosion.
https://endless-sphere.com/forums/viewtopic.php?f=31&t=75494
chris_kline
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looks well made, would be interesting to know what the max erpm is on that.
im thinking it would need a watercooling heat exchanger on those fets for a surfboard application though. thing is on watercraft you are operating at a high load constantly, its like gong uphill all the time.
about mgm, maybe i had a bad experience, i was dealing with one sales guy, who then handed me over to an apprentice sales staff, who then left, and was replaced by another apprentice who didnt ever reply. all in all the experience was pretty terrible
im thinking it would need a watercooling heat exchanger on those fets for a surfboard application though. thing is on watercraft you are operating at a high load constantly, its like gong uphill all the time.
about mgm, maybe i had a bad experience, i was dealing with one sales guy, who then handed me over to an apprentice sales staff, who then left, and was replaced by another apprentice who didnt ever reply. all in all the experience was pretty terrible
fabianpusch
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Yes MGM is really good in selling the controllers but if you have a problem, it is always the battery or e.g. the lengths of the cables.
I have solved this by putting two additional banks of caps shortly before the ESC.
And still the battery can be an issue....I am now using military specs cells from Kokam.
Nice run with the gasoline powered board.
Are you using molds?
By Fabian
I have solved this by putting two additional banks of caps shortly before the ESC.
And still the battery can be an issue....I am now using military specs cells from Kokam.
Nice run with the gasoline powered board.
Are you using molds?
By Fabian
chris_kline
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mould for the board? no this one was hand made, from expanded polystyrene foam and wet lay carbon like the last one, i just got a bit better at doing it this time
the motor compartment was made with a mould though, and prepreg carbon, but i dont have a big enough autoclave for the main board to fit
the motor compartment was made with a mould though, and prepreg carbon, but i dont have a big enough autoclave for the main board to fit
Has anybody thought about using a VESC 6 300, or SLS (sinusleistungssteller.de)?
Lehner Torqstar has sinusoidal BEMF so it would be even more efficient if driven with a sine wave controller.
http://www.sinusleistungssteller.de/FuriaOne2012.html
Lehner Torqstar has sinusoidal BEMF so it would be even more efficient if driven with a sine wave controller.
http://www.sinusleistungssteller.de/FuriaOne2012.html
chris_kline
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yeah i contacted them when i was in the middle of my troubles with mgm.
they said they werent really able to get the erpm needed
they said they werent really able to get the erpm needed
Bazaki
10 kW
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The gasoline jetboard makes almost the same sound as the electric version in your video's 
I can imagine that trouble after trouble is demotivating you.
I also stopped for the same reason with my electric jetboard, but now my electric hydrofoil is almost finished. It has so many benifits, only need about 900 watts to Foil, more silent, easier, cheaper and it is the feeling of flying and surfing.
Maybe i will build a prop driven surfboard, like the waterwolf for shallow water.
https://www.esurf.com/ did you see this?
I can imagine that trouble after trouble is demotivating you.
I also stopped for the same reason with my electric jetboard, but now my electric hydrofoil is almost finished. It has so many benifits, only need about 900 watts to Foil, more silent, easier, cheaper and it is the feeling of flying and surfing.
Maybe i will build a prop driven surfboard, like the waterwolf for shallow water.
https://www.esurf.com/ did you see this?
chris_kline said:
Yes most controllers struggle to do high RPM in FOC mode, even the mentioned Nucular controller does not like RC motors that much.
If 16s and 300/450A are high enough for your setup i would give the VESC6 75/300 a try 8)
In terms of ERPM in FOC it should be one of the best controller available out there.
Silixcon controllers also seem to be a good choice for RC motors check them out:
http://silixcon.com/products/
chris_kline
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yeah, those Esurf boards look very well made, next gen stuff.
but they cost like 20'000 so for that money, you would expect the best!
but they cost like 20'000 so for that money, you would expect the best!
Did some water tests.
Two major problems:
1. Sealing of my polycarbonate glasses is not good. Had water in my board, thats why I had to stop testing.
2. I am too heavy
In my design phase I thought that it will produce enough lift when accelerating. So I designed 100l of volume. The board weight is 30kg + my 85kg.
Result is, that I push it completely under water and it cannot accelerate. Now I am thinking of two wings to get more uplift.
How much volume do your boards have ?
Here short a video which shows 10.000rpm @ 4kW: [youtube]u-paXRV5_DM[/youtube]
Two major problems:
1. Sealing of my polycarbonate glasses is not good. Had water in my board, thats why I had to stop testing.
2. I am too heavy
In my design phase I thought that it will produce enough lift when accelerating. So I designed 100l of volume. The board weight is 30kg + my 85kg.
Result is, that I push it completely under water and it cannot accelerate. Now I am thinking of two wings to get more uplift.
How much volume do your boards have ?
Here short a video which shows 10.000rpm @ 4kW: [youtube]u-paXRV5_DM[/youtube]
chris_kline
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my electric jetsurfer has about 150l of volume
my gas jetsurfer has about 90l of volume.
my gas jetsurfer sinks if im not moving, but i wanted it smaller to be more maneuverable.
if you decrease your nozzle diameter at the small end, you will get a lot more thrust, and will get on the plane almost immediately.
looks great though! now its the time for endless fine tuning to get everything sweet. i spent ages fine tuning pretty much every aspect of mine over the course of a year to get it working well.
do you have any video of it with you on it at full throttle?
my gas jetsurfer has about 90l of volume.
my gas jetsurfer sinks if im not moving, but i wanted it smaller to be more maneuverable.
if you decrease your nozzle diameter at the small end, you will get a lot more thrust, and will get on the plane almost immediately.
looks great though! now its the time for endless fine tuning to get everything sweet. i spent ages fine tuning pretty much every aspect of mine over the course of a year to get it working well.
do you have any video of it with you on it at full throttle?
i am using the vesc6 75/300 on my efoil, running 100A (battery) continious with no cooling at max 70°c, above you will need to add a watercooling system for a esurf, i think your board is to small to acheive planning speed, mine (efoil) is 90L and it takes this power and the wing to take off and it needs the same power to go about 35km/h (big wing and propeller duct)
the vesc6 75/300 is very nice and let you do all kind of setting but it s expensive... , a bit overkill for a efoil, but nice for a esurf
battery cables are about 25cm long (2x10awg)
motor cables are about 200cm long (10awg , cooled by water)
no capacitors
no amp pics above max settings 100A battery and 130A for the motor, no heat problem beside the battery pack: running 12s8p 30Q, above 7.5A/cell the battery starts to heat to the manufacter specification @60°C , the battery is too small (i knew that just trying to save some weight...)
the vesc6 75/300 is very nice and let you do all kind of setting but it s expensive... , a bit overkill for a efoil, but nice for a esurf
battery cables are about 25cm long (2x10awg)
motor cables are about 200cm long (10awg , cooled by water)
no capacitors
no amp pics above max settings 100A battery and 130A for the motor, no heat problem beside the battery pack: running 12s8p 30Q, above 7.5A/cell the battery starts to heat to the manufacter specification @60°C , the battery is too small (i knew that just trying to save some weight...)
chris_kline said:my electric jetsurfer has about 150l of volume
my gas jetsurfer has about 90l of volume.
my gas jetsurfer sinks if im not moving, but i wanted it smaller to be more maneuverable.
if you decrease your nozzle diameter at the small end, you will get a lot more thrust, and will get on the plane almost immediately.
looks great though! now its the time for endless fine tuning to get everything sweet. i spent ages fine tuning pretty much every aspect of mine over the course of a year to get it working well.
do you have any video of it with you on it at full throttle?
I was not surfing on it at full throttle yet. When I sit down on it, it is more like a submarine and cannot accelerate
My nozzle has 50mm at the end. How about yours ?
chris_kline
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45mm nozzle, 76 diameter prop, with 70mm pitch
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