Electric Hydrofoil/E-Foil

notafraidtotry said:
Hiorth said:
Just posted some illustrations of our 3d models here, will continue to post updates as we go forth. https://www.facebook.com/media/set/?set=a.10159438659855144&type=1&l=2e97c1f9fb

Cheers
Click to expand...

They look great.

We are still working on various drive options. I have updated the parts list based on feedback here but the plan will be to ensure we can test different drives but keep the same electronics, batteries etc.

The OpenROV teams use bog standard out-runners sprayed with silicon spray before each dive and rinsed with fresh water. Sync issues are a possibility but seem to be when you use too large a prop and the ESC expects to see higher speeds. I'm still tempted to try this approach out but guess the in runner and gearbox route will be the best and is of course tested. The gearboxes just seem to be very expensive.

I have even started looking at the large professional cordless drills. My hope is still to find something that already exists that can be re-purposed. You can get used 36V cordless drills without batteries for under £50. The Dewalt DC900 for example is brushless (motor may or may not be usable) but the planetary gearbox is all metal. Output speed is 1,400 RPM with the motor running at around 22,000 RPM so getting into the right ballpark. These things retail at well over £500 new so they are well made. The clutch can be locked out although might be useful.

Anyone looked at using them?
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We have looked into using a cordless drill planetary gear, the main issue we ran into is that the drill motor has a pinion gear directly mounted on the drill motor shaft. So if you are going to use your own motor, you will have to get a special made pinion gear (assuming the one on the drill motor shaft does not fit your motor shaft). All in all I belive the solution will not be as good (if you change the motor) and total cost will be more or less the same as buying an in-line gearbox (200Euro), that has a shaft clamp on the input side.

But If the motor from the drill works, then It could work well, as long as the Diameter is not to large (drag).
 
toto44 said:
The pushing force is not bad, but it will not create speed. You can already see from the pitch of the prop.
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Yes, it is not "strap to your board with duct tape solution" for sure. Idea is, to find inexpensive of the shelf platform as near as possible to our requirements and then start hacking.
Looking at the picture trough a prism of rainbow diffraction glasses, I see a very short to do list actually. :mrgreen:
a.Fix existing shaft to board at desired length.
b.3D print the wing and prop
c.Over volt the motor a little, if needed, remember, DD, no gearbox loses (yes it is brushed unfortunately)
d.Throw all the electronics crap with batteries into sealed plastic box (pacifimeister style)
e.And give it to your Lady for testing, as she does not have hanging body parts easily chopped off by the propeller. :)

Ok, now I go and prepare my self being smashed face down to the ground by the reality.
 
parabellum said:
toto44 said:
The pushing force is not bad, but it will not create speed. You can already see from the pitch of the prop.
Click to expand...
Yes, it is not "strap to your board with duct tape solution" for sure. Idea is, to find inexpensive of the shelf platform as near as possible to our requirements and then start hacking.

Ok, now I go and prepare my self being smashed face down to the ground by the reality.
Click to expand...

As has been mentioned, there are a few physical limitations of that motor which will present a few roadblocks. I've thought about using trolling motors a lot and have discovered that they only produce thrust at very very low water speeds. As you get foiling, the speed will increase dramatically but the thrust will diminish because of the low blade angle. Changing to a higher pitch prop will increase the power and torque requirement. Some back of the envelope calculations on this very thread suggest a power requirement of the motor of 2-3kW.

Regardless, it will be nice to see someone try this instead of just a bunch of us talking about it. I wish you luck and look forward to any results you can share with us.
 
NolaDoogie said:
Some back of the envelope calculations on this very thread suggest a power requirement of the motor of 2-3kW.
Click to expand...
Yes, it is what you need to come out of water first. This motor could do it for short bursts, with 9-11S LiPo, only limitation are the brushes, brush-less trolling motor is just to expensive for proof of concept experiments. RPM potential will increase ~66% on 11S as well.
Screenshot from 2017-07-25 12-06-05.png
My main concern is actually its size and weight. Is wing size absolute or can vary according to design and weight?
Wondering if original speed controller with some mods could be used at 10S.
NolaDoogie said:
Regardless, it will be nice to see someone try this instead of just a bunch of us talking about it. I wish you luck and look forward to any results you can share with us.
Click to expand...
Talking, hydrodynamics and little math is important indeed, I have no clue of what I am doing, I was born to crawl, not to swim nor fly. Lets wait for the motor to come in.
 
ropower86 said:
I am looking to purchase a Neugart Planetary GearBox. I know the ple 40 gearbox I need to choose but which gear ration do I need to get?
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We ordered the PLE 40-005 (5:1) ratio. Which will give us about 4000 rpm on the propeller (unloaded), and probably less (around 3-3500 in real life). Lower rpm with bigger prop gives higher effciancy, on the other side, too large prop may result in torque overload for gearbox/motor and may pull air more easily if it gets to close to the surface.

Pacifimeister used Parker 7:1 and it worked. The neugart PLE and the Parker pv40 gearbox is mechanically more or less the same so an ratio in that ballpark with correct prop should work.
 
Hiorth said:
ropower86 said:
I am looking to purchase a Neugart Planetary GearBox. I know the ple 40 gearbox I need to choose but which gear ration do I need to get?
Click to expand...

We ordered the PLE 40-005 (5:1) ratio. Which will give us about 4000 rpm on the propeller (unloaded), and probably less (around 3-3500 in real life). Lower rpm with bigger prop gives higher effciancy, on the other side, too large prop may result in torque overload for gearbox/motor and may pull air more easily if it gets to close to the surface.

Pacifimeister used Parker 7:1 and it worked. The neugart PLE and the Parker pv40 gearbox is mechanically more or less the same so an ratio in that ballpark with correct prop should work.
Click to expand...

Can I ask where you ordered the PLE 40 from and how much you got it for? I have been looking in the UK but couldn't find an online distributor.

Thanks......
 
notafraidtotry said:
Hiorth said:
ropower86 said:
Can I ask where you ordered the PLE 40 from and how much you got it for? I have been looking in the UK but couldn't find an online distributor.
Thanks......
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Click to expand...
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HMK Automation should be able to get them. They will be more expensive than the Torqeedo 1003 version though. The Torqeedo 1003 gearbox is around 7-8:1 in ratio (haven't calculated it exactly just watched it spin). I emailed every Torqeedo dealer until I found one that had the gearbox in stock.
 
Jezza said:
notafraidtotry said:
Hiorth said:
ropower86 said:
Can I ask where you ordered the PLE 40 from and how much you got it for? I have been looking in the UK but couldn't find an online distributor.
Thanks......
Click to expand...
Click to expand...
Click to expand...

HMK Automation should be able to get them. They will be more expensive than the Torqeedo 1003 version though. The Torqeedo 1003 gearbox is around 7-8:1 in ratio (haven't calculated it exactly just watched it spin). I emailed every Torqeedo dealer until I found one that had the gearbox in stock.
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Alternatively, grab this: http://www.ebay.co.uk/itm/Torqeedo-electric-trolling-outboard-/263094548721?hash=item3d41a838f1:g:KfAAAOSw2kZZbgTD and strip it for the gearbox...
 
Jezza said:
Alternatively, grab this: http://www.ebay.co.uk/itm/Torqeedo-electric-trolling-outboard-/263094548721?hash=item3d41a838f1:g:KfAAAOSw2kZZbgTD and strip it for the gearbox...
Click to expand...

Just spotted that one too :) Suspect it will go for a lot more than the cost of a new standalone gearbox.
 
notafraidtotry said:
Jezza said:
Alternatively, grab this: http://www.ebay.co.uk/itm/Torqeedo-electric-trolling-outboard-/263094548721?hash=item3d41a838f1:g:KfAAAOSw2kZZbgTD and strip it for the gearbox...
Click to expand...

Just spotted that one too :) Suspect it will go for a lot more than the cost of a new standalone gearbox.
Click to expand...

It will go for more than a gearbox, but remember that it does also come with batteries which you might be able to use.
 
A nice and long thread you have here. Just my two cents - sometimes simplest solution is the best solution. Why not use an outrunner, and hide it inside board - and for drive use similar system as in ordinary, gasoline outboards - straight angle gearbox. So much cheaper, safer for electronics and easier to work with, especially on prototype. Plus possible to use cheaper motors. Minus - slightly more weight. But hey - this is not an airplane, and I would choose + 1kg for sake of better efficiency and fool-proof design. And - less wetted area is always better.
 
staska said:
A nice and long thread you have here. Just my two cents - sometimes simplest solution is the best solution. Why not use an outrunner, and hide it inside board - and for drive use similar system as in ordinary, gasoline outboards - straight angle gearbox. So much cheaper, safer for electronics and easier to work with, especially on prototype. Plus possible to use cheaper motors. Minus - slightly more weight. But hey - this is not an airplane, and I would choose + 1kg for sake of better efficiency and fool-proof design. And - less wetted area is always better.
Click to expand...

Actually that would greatly complicate the solution. One would have to design a whole new mast section to incorporate the gearing, thus increasing the width of the mast. This would then increase the drag and would then lead to a larger power requirement. The motor getting wet is not really the issue. It's pretty easy to seal an outrunner.
I think that the cost of the motor and gearbox are small in comparison to what one will spend on batteries once they have a working system.
 
Hiorth said:
ropower86 said:
I am looking to purchase a Neugart Planetary GearBox. I know the ple 40 gearbox I need to choose but which gear ration do I need to get?
Click to expand...

We ordered the PLE 40-005 (5:1) ratio. Which will give us about 4000 rpm on the propeller (unloaded), and probably less (around 3-3500 in real life). Lower rpm with bigger prop gives higher effciancy, on the other side, too large prop may result in torque overload for gearbox/motor and may pull air more easily if it gets to close to the surface.

Pacifimeister used Parker 7:1 and it worked. The neugart PLE and the Parker pv40 gearbox is mechanically more or less the same so an ratio in that ballpark with correct prop should work.
Click to expand...

There is a Neugart company 6 miles from me in Charlotte North Carolina. What do you think about the PLE 40-008, would that do the job too?
 
Yes and no . It is ok to use leg from 2hp outboatd motor. And as must you still need a prifile, not a sheet. Battery 600 eu for unit buildfrom tesla batteries. For 2 kwh.
 
******* ATTENTION *******

This is a warning to all, DO NOT BUY GEARBOX THAT IS MADE IN CHINA! They are made out of low alloy and gears will break under load. That is why their gearbox is cheap and it will not work for our project.
 
ropower86 said:
******* ATTENTION *******

This is a warning to all, DO NOT BUY GEARBOX THAT IS MADE IN CHINA! They are made out of low alloy and gears will break under load. That is why their gearbox is cheap and it will not work for our project.
Click to expand...

+100 same experience. You are not flying on it. But it make you hurt if broke at bad moment.
 
Jezza said:
It's pretty easy to seal an outrunner.
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I may repeat my self, but again, how will you cool an sealed out-runner? With, for example, 1000W IN constant and good quality motor at 80% efficiency when cool (any raise in temp craps conductivity, raising copper loses). You have to remove 200W+ of heat.
Out-runners depend on,dynamic air cooling, air pumped between rotor and stator winding (by oncoming wind in air planes or centrifugal action or rotor blades), but only conductive path left is, static thermal conductivity copper>stator iron>stator aluminium core>?>? which looks comparably crappy. Many on ES have been there and have done that, including myself.

Yes, I did looked at water-cooled out runner at alien, but a) I am sceptical about efficiency of his motors (at best 70% round trip) and then b) its cooling design with its tiny coolant in/outlets and uncnown channelling design.

So please, share you solution, before I get crazy. :|
 
parabellum said:
Jezza said:
It's pretty easy to seal an outrunner.
Click to expand...
I may repeat my self, but again, how will you cool an sealed out-runner? With, for example, 1000W IN constant and good quality motor at 80% efficiency when cool (any raise in temp craps conductivity, raising copper loses). You have to remove 200W+ of heat.
Out-runners depend on,dynamic air cooling, air pumped between rotor and stator winding (by oncoming wind in air planes or centrifugal action or rotor blades), but only conductive path left is, static thermal conductivity copper>stator iron>stator aluminium core>?>? which looks comparably crappy. Many on ES have been there and have done that, including myself.

Yes, I did looked at water-cooled out runner at alien, but a) I am sceptical about efficiency of his motors (at best 70% round trip) and then b) its cooling design with its tiny coolant in/outlets and uncnown channelling design.

So please, share you solution, before I get crazy. :|
Click to expand...

Go through this page https://twitter.com/SCPMI/media
They use outrunners and it seems they let the water cool them. I still think it is better to use an inrunner and gearbox for this project though as you will get more power and efficiency.
 
Any drawing is better than 1000 words. In the attachment are two motors - one c6364 230kv which is maxed at 2850 watts, and pancake generator from inverter generator ig2000 which is rated at 2000 watts continuous. Cooling - just mount stator to aluminum plate. Burst i think is at least 4000 watts. will have to rewind it for lower voltage . Weight is twice as much +-. But still - this think wont broke on first rock/straw/plastic bag which will be sucked into your propeller. I could argue of using inrunner with gearbox for clear water - but for smaller lakes/canals etc - it wont do it job. It will brake on any bigger impact. Any source of proper gears for good gearbox ?

And yes - i bought motor to use as generator with honda gx31 engine, and will use generator as a motor :mrgreen:
 

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staska said:
But still - this think wont broke on first rock/straw/plastic bag which will be sucked into your propeller. I could argue of using inrunner with gearbox for clear water - but for smaller lakes/canals etc - it wont do it job. It will brake on any bigger impact.
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I think you may be forgetting that for anything to be sucked into the prop, It first needs to make i past the mast, foil wing and kort nozzle. The brushless motor into planetary gearbox is already an industry proven design with years of practical use by Torqeedo. And also used on the like of the waterwolf electric surfboard. I think it's safe to say it works.

It will be interesting to see your results by doing it a different way though.
 
I thought I'd throw in some progress pictures as I have almost completed the test parts phase and can then move into making the final parts.

20170726_192908.jpg

20170726_192639.jpg

20170726_193430.jpg
 
Jezza said:
staska said:
But still - this think wont broke on first rock/straw/plastic bag which will be sucked into your propeller. I could argue of using inrunner with gearbox for clear water - but for smaller lakes/canals etc - it wont do it job. It will brake on any bigger impact.
Click to expand...

I think you may be forgetting that for anything to be sucked into the prop, It first needs to make i past the mast, foil wing and kort nozzle. The brushless motor into planetary gearbox is already an industry proven design with years of practical use by Torqeedo. And also used on the like of the waterwolf electric surfboard. I think it's safe to say it works.

It will be interesting to see your results by doing it a different way though.
Click to expand...

But it will happen. I do totally agree on industrial heavy-duty planetary gearbox with industrial brushless - just don't know where to find them for decent price.
 
staska said:
But it will happen. I do totally agree on industrial heavy-duty planetary gearbox with industrial brushless - just don't know where to find them for decent price.
Click to expand...

What exactly do you class as an industrial planetary gearbox and industrial brushless?
 
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