Author Topic: Foildrive motor  (Read 41191 times)

PonoBill

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Re: Foildrive motor
« Reply #30 on: July 07, 2021, 07:47:51 AM »
Yes, watts is the power measure, but for a boosting drive you don't need to "get up", you just need some help. Anything that will push you to 3 mph will be better than nothing. There are a lot of people that can get up on a foil just paddling. If they are generating more than 100 watts I'll eat my calculator--paddling has to be the shittiest way to make power ever invented. A fit adult adept at a sport generates between 50 and 150 watts. Elite cyclists generate 300 and can burst to about 1000 but that probably requires drugs. 240 watts, if it's all delivered efficiently (probably more like 175) would be like having Laird help you paddle but he weighs 4 kG

3000 watts is a nice number for a full-on eFoil, where you don't do anything but push a button and balance. Even then, that amount of power will only be used if you are going stupid fast, like 40mph. On any eFoil the first thing you learn to do is not give full throttle to get up, the second thing is to throttle back quickly when you're up.
« Last Edit: July 07, 2021, 07:56:11 AM by PonoBill »
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

jondrums

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Re: Foildrive motor
« Reply #31 on: July 07, 2021, 01:45:19 PM »
This post has me thinking about a few things. 

quick run of the numbers:
Let's assume regardless of cadence that the paddler is pulling on the paddle half the time, and half the time is spend in recovery - pulling the paddle out of the water and returning it into the water for the next stroke.  We can ignore power used for recovery and just focus on the power generated in the pull stroke.   I just used a tape measure and estimated that I move my bottom hand about 16-18" on a power stroke.  Wild guess says I'm pulling on the paddle with 30lbs of force.  turns out this would be 60W continuous.    So, yeah less than 100W

In terms of cruising around - it shouldn't require more power than it takes to pump the foil.  That's gotta be less than 1000W or nobody would be able to pump around for more than a few seconds.  But I guess we have to remember that the propeller is pretty inefficient and we've added the drag of the motor.  I agree, it sure seems like 3000W would only be needed for going really fast.

PonoBill

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Re: Foildrive motor
« Reply #32 on: July 07, 2021, 09:38:34 PM »
Paddles are less efficient than propellors--a lot less. Even if you engage your core you're using small muscles. decent bicyclists are using the largest, most powerful muscles and have an extremely efficient power conversion system. A really good bicyclist puts out 150 watts. We are puny motors. One horsepower is 750 watts.
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

Solent Foiler

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Re: Foildrive motor
« Reply #33 on: July 08, 2021, 01:35:11 AM »
A really good bicyclist puts out 150 watts.

Sorry to be a pedant, but done a lot of cycling!

You're missing a 0 (a typo I'm sure!)

Should be 1500 watts, which will be close to peak, depending on what period you measure over ..

A pro cyclist Functional Threshold Power (loosely described as the power they can sustain for an hour) will be between 5 to above 6 Watts per kg, as power output is very dependent on weight. So a 60kg climber will have a sustainable hour power of around 360 watts.

Wake Thief calculated that foil pumping needs about 300 watts, so that sets the above in context... Pumping is hard work! At my best my FTP was just around 305 watts, giving me an FTP of around 4.5 watts/kg.
« Last Edit: July 08, 2021, 02:06:11 AM by Solent Foiler »
I'm 5'10", 66kg riding:
Swift Foil Boards custom 4'10 x 19.5" 35L
Gong Lethal 4'6 65L
Axis ART 799, 899, 1099, HPS 880 US & CS Adv fuse, 85cm mast
Gong Fluid L-S, XXL-S on 85cm and 65cm mast
Takuma RS 5.1, 4.3, 3.5

jondrums

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Re: Foildrive motor
« Reply #34 on: July 08, 2021, 07:52:44 AM »
Yeah, my best half hour of cycling on a stationary bike is 320W average (plus or minus the inaccuracy of the watt meter on the bike).   But I’m just about dead after 20seconds of pumping.  Cycling is quite a bit more efficient than pumping


SUPJorge

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Re: Foildrive motor
« Reply #36 on: August 25, 2021, 07:57:44 AM »
I've been following the original one pretty closely --> https://www.foildrive.com.au/shop.

The guy in this YouTube video appears to get foiling in almost flat water --> https://www.youtube.com/watch?v=4R80rzt5Dmw&t=366s

It really does look promising, may open up the East Coast of Florida for year-around foiling, but after shipping and duties it comes out to more than $3000. The value-added component I see is the pass-through opening for the foil mast in the torpedo-shaped propeller. Anyone have any ideas were we can buy or make something like this?
14' SIC Bullet V2 - 9'1" Naish Hokua X32 LE

PonoBill

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Re: Foildrive motor
« Reply #37 on: August 25, 2021, 09:09:17 AM »
A really good bicyclist puts out 150 watts.

Sorry to be a pedant, but done a lot of cycling!

You're missing a 0 (a typo I'm sure!)

Should be 1500 watts, which will be close to peak, depending on what period you measure over

Nah. I should have been more precise about what I meant by "really good". I wasn't talking about the far end of the bell curve, just past the midpoint. 5 watts per kg is deep into the elite level, and irrelevant to the point--we're talking about what it takes to make the drive useful, not what is possible for a tiny number of dedicated athletes who probably would never pick up a paddle--bulks up muscles that are useless for bicycling. 1500 watts--you're dreaming unless perhaps you weigh 300kg with 2% body fat. If you can produce 1200 watts for a few seconds (20 watts per kg at 60kg--which is the average weight for elite climbers) you're in the company of a few hundred people on the planet.

Mark Ribcoff, here in Hood River, got one of the foildrives for downwind SUP foiling and is in love with the thing. I should probably just buy one, but can't make myself do it, so I'll build one. Fortunately, I don't have to commit a lot of resources to do that. I've got the two drive systems I bought to build an efoil and the towbot. They fit the narrow Takuma or Slingshot masts. The power cables run up the inside of the mast. I can actually just build what I need for an efoil and just turn the mast upside down and reroute the cables to position the motor close to the board instead of close to the foil. It won't be optimal position for the efoil, but damned close. I'll pick up a slingshot mast this morning and quit screwing around and get this done.

Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

Hdip

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Re: Foildrive motor
« Reply #38 on: August 25, 2021, 09:09:32 AM »
Anyone have any ideas were we can buy or make something like this?

Besides the parts listed above. All your DIY info for efoil stuff comes from foil.zone

This thread for example was made back in 2019.

https://foil.zone/t/mini-motor-for-sup-surfing/4192/3

Esteban

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Re: Foildrive motor
« Reply #39 on: August 25, 2021, 11:45:09 AM »
quite an interesting thread....heres another thought. If your foil board had a couple thruster boxes you could double up on that finbox Boost drives and use that to get you going enough to stay up pumping or riding on swell with the foil and the Boost drives would no longer be in the water adding drag? hmmm


SUPJorge

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Re: Foildrive motor
« Reply #40 on: August 25, 2021, 07:22:43 PM »
Pono, I'll take the other drive system and make two of everything else. I'll paypal you.

Ps. I'll do 1800 watts for a few seconds. Not bad at 59.
14' SIC Bullet V2 - 9'1" Naish Hokua X32 LE

ninja tuna

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Re: Foildrive motor
« Reply #41 on: August 25, 2021, 08:54:15 PM »
Oh, I need one of these.  I could get a ton of use out of it.

and this was interesting.
https://www.uci.org/news/2019/track-sprinting-a-question-of-watts


Now add one of these on to all the new HA foils and small unbreaking wave spots are now your private playground

exhibit A for the jury

https://www.youtube.com/watch?v=vJMhKZkxNpw
« Last Edit: August 25, 2021, 09:02:28 PM by ninja tuna »

PonoBill

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Re: Foildrive motor
« Reply #42 on: August 26, 2021, 10:18:04 PM »
So I made this today...  ...Foildrive on steroids. About 3500 watts with gear reduction to make it efficient. If this can't get my fat ass downwind foiling the next step is a jetpack.
« Last Edit: August 26, 2021, 10:20:46 PM by PonoBill »
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

PonoBill

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Re: Foildrive motor
« Reply #43 on: August 26, 2021, 11:59:08 PM »
I'm going to have to shim the heck out of that plate--this silly board has way too much rocker. Once all the flipsky parts come I'll have this beast up and running in a week or so. I think I'm going to do about the same size battery they do. Probably a little bigger because I'm gonna do 14S: 52V . If it leaks a little current I might stun a few salmon.
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

JonathanC

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Re: Foildrive motor
« Reply #44 on: August 27, 2021, 01:29:04 AM »
Hey Bill, that’s a weapon!
I’m very keen to make some sort of mast mount foil drive, at 140 pounds don’t need the steroid version and would be interested to hear if you think I could power it with one of the Stihl garden equipment batteries we have. There is a 36v 261 Wh. battery, Stihl have a belt battery socket, effectively a portable socket which simplifies connections (all mounted in waterproof box). That battery will run a full size lawn mower for a crazy long time, surely it can get my skinny arse up onto some downwind waves.
I don’t know what I’m looking at in terms of motors/controllers and would welcome any tips, particularly regarding suitability for 36v. Possibly the Flipsky F4125 but no clue if this would have enough grunt for foil drive application.
Thanks
« Last Edit: August 27, 2021, 01:40:08 AM by JonathanC »

 


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