El Cheapo Foil Drive

[surfcowboy]

Bill, weight is something I hadn't considered. Yeah, let a lightweight try it.

Also, maybe the efoil guys can recommend a motor replacement? There's a lot in that kit that's "done"if the boost can be boosted. Also there are a ton of props you can print. Matching that seems to be a place to get some efficiency.

[Vancouver_foiler]

Yeah, I'm on the list for the boost fin as well. If it's a scam it's an elaborate one, but having played with this fin with a substantially larger motor and battery I doubt it does anything useful. Which is probably the real reason why we're not hearing anything new.

the bad news for the fin I'm trying is that it's too weak to really do much. It will push the board along at perhaps 2mph, which at first seems like it might be enough to be a help in waves. But the weight added from the battery pack (probably ten pounds) and the general clumsiness and drag of all that stuff make the little bit of boost probably not worth the effort. I still haven't tried it in real waves or swell, mostly because my knee is giving me fits, making it hard to get to my feet just to do ordinary foil surfing. But I'm not seeing much benefit in little swell, which is bad news since they are traveling so slow. I should have been able to paddle fast enough with the added boost to keep up--at least briefly--but I couldn't.

I'll get someone else to try this thing in the surf, but I think I've established the below lower bound for how much power we need for a practical boost. I can't find any spec from the company that sold me this fin for the wattage of the motor, but my guess given performance is that it's somewhere in the 100 watt range. The issue might be propeller efficiency as well, though the folding prop on the successful Australian booster looks fairly crappy as well. I'm surprised that it works as well as it seems to.

How about trying Two motors?!
Lol, kind of defeats the El Cheapo thing but then again a foil drive is 3k USD isn't it?

[PonoBill]

I'm going to fit a more powerful motor. I'll have to rework the electronics and probably beef up the controller, but I can do all that. I wanted to change the control transmitter anyway. I'll also print a better prop. There are lots to choose from, as the cowboy says. The printer I have here doesn't have enough beans in the print head to handle polycarbonate, but I'll do an ABS one (which might work fine with whatever motor will fit this housing) while I'm considering a printer or just a printer head upgrade.

I got my knee shot up today and it's feeling good. And I'll start with a PT this week to work on getting it stronger. I'm back on intermittent fast, so with a bit of work I might be the lighter, agile guy that this thing needs. Well, that and some more power.

[juandesooka]

Boost Fin...I considered seeking the refund they promise, but figured for $200 I'll let it roll, see how it plays out.  Though my imagination does kick in for elaborate scams.

For this and the other el cheapo: I lean towards it probably not working, just not enough juice for what we need.  In contrast, we are well on the way to a Faux Drive diy knock off, the parts add up to about $1000cdn, or about $700US.   Luckily we have a friend with some know how on RC boats to put it together.  Sounds like you have the know-how too.

That basically gets you a semi e-foil, without water cooling needed and a fraction of the battery pack.  From what I've seen it has enough juice to get up on foil for a minute efoil style (though at risk of burning it). For jump starts, maybe 20-30 boosts in a session.  A friend with it is doing downwinders, he uses just 10-20% battery power in 20km+ runs.  That's rad!

[surfcowboy]

J, that's rad man! I love the group effort and drafting an R/C guy. Perfect. That price is great and you can tailor it to what you need.

This will open up DW to so many people.

[PonoBill]

Luckily we have a friend with some know-how on RC boats to put it together.  Sounds like you have the know-how too.

Yes, I've been doing fairly serious electronic stuff since I was 12 or 13. So 60+ years of making smoke and frying expensive parts. I also got into RC when the servo (called an escapement) was actually powered by rubber bands. So yeah, tubes and high voltage batteries. Weird to contemplate as I just built a goofy little dancing robot to add some spice to the putting green we installed for Diane. The little bugger doesn't do much, but it's got four servos and enough computing power to make the old PDP-1 I first learned programming on look like a four-function calculator.



The little kit came with an arduino. I'm going to swap it out with an ESP32 and add a phone interface with node-red controls. The "eyes" are a sonic rangefinder and it works pretty well for object avoidance. With only 4 degrees of freedom the movements are slow and a bit limited, but sometimes simple is good, I rewrote the dance routine in about five minutes and I added some showstopper moves in the fifteen minutes since I uploaded the video. In the golf game he'll wander back and forth in an open tunnel and when a ball goes by he'll break out some dance moves. One stroke penalty for hitting the robot, two if you knock it over, and four if we deem it intentional. Diane is already planning some costumes.

Brother Bob (stoneaxe) is making me a windmill based on the Eastham mill on his CAM router. Yeah, it's stupid stuff, but fun.

[juandesooka]

Yeah, it's stupid stuff, but fun.

Haha, like the ads for Comedy Channel "time well wasted".  As long as you're having fun, anything goes! 

My friend with the RC knowledge, he also had the gumption to buy a 3D printer.  That's a game changer for the DIY potential.  But another buddy said he's been getting parts made by this company: https://www.hubs.com   He said cheap and good quality, replaces need for a 3d printer...apparently there's lots of providers out there, just need the files.  On that note, the prop and mast mounts used by FD were reportedly based on files originally posted  to Foil Zone, then pulled once they started making them commercially.  Since then, my understanding is new versions of these files have since been posted again, so they are publicly available for those inclined.  FD sells spare parts but only to people who already bought an FD package.

[Hdip]

http://www.waveescort.com/

They made a tow boogie that will come back and pick you up after your wave.

[Dontsink]

Boost Fin...I considered seeking the refund they promise, but figured for $200 I'll let it roll, see how it plays out.  Though my imagination does kick in for elaborate scams.

For this and the other el cheapo: I lean towards it probably not working, just not enough juice for what we need.  In contrast, we are well on the way to a Faux Drive diy knock off, the parts add up to about $1000cdn, or about $700US.   Luckily we have a friend with some know how on RC boats to put it together.  Sounds like you have the know-how too.

That basically gets you a semi e-foil, without water cooling needed and a fraction of the battery pack.  From what I've seen it has enough juice to get up on foil for a minute efoil style (though at risk of burning it). For jump starts, maybe 20-30 boosts in a session.  A friend with it is doing downwinders, he uses just 10-20% battery power in 20km+ runs.  That's rad!

Sounds really good!
How much will it weigh?

[juandesooka]

Sounds really good!
How much will it weigh?

according to crappy bathroom scale....3-4lbs.  I've tested it out maybe 6 times now.  Unfortunately, 3 of 6 I broke 3d printed pieces, partially due to my kooking out, and partially bad luck (eg I think I may have hit some wood in the water once). 

Only once used in waves: you can definitely catch waves that are otherwise unrideable. But: if there's no power in the wave, you better be a good pumper, not much energy to work with. You need to get up high on foil quick, as the motor drag will cause you come off foil.

Flat water: it has great potential for pump practice for those unable to dock start and no tow partner.  My pump monkey buddy could get up with motor and do sustained 40-60 second pumps.  My max was maybe 10-15 seconds, I'm working on it. 

Boost fin: they said 2000 have arrived in USA, I wonder if I will finally get mine, 2+ years later.  I suspect it won't work for foiling, but my wife might enjoy it on her longboard, luxury surfing. 

[PonoBill]

Yeah, I've been breaking them right and left just testing. the best filament so far is carbon fiber in Polycarbonate, but I still managed to break one today. Pulled the plugs out getting it apart. That's not a likely failure mode and I'm going to rework some of the design to reinforce the plastic with metal screws. I've got three 3D printers running steadily making stuff for me to break. I'm upgrading the printers on the fly to make them more capable. Fun stuff. Good thing I like this shit--and the wind has sucked lately anyway.

[juandesooka]

edit...crappy scale indeed...the box with batteries and controls is 6lbs, so add in the motor and we're probably up to 9-10lbs total

Bill: sounds like polycarbonate is best bet.  I know others doing this that haven't had the same fail rate...mine were half my fault unfortunately (like forgetting to bolt my gofoil mast plate, so SO kooky).  I am going to experiment with injecting in some epoxy filler, too, see if that may strengthen it a little.

[PonoBill]

I think that three-piece design is a bit wonky. It might make sense for injection molded or metal parts in the event that you didn't want to retool for every mast or for new motor choices, but 3D printed parts break along the build line, and the plugs are ripe for breaking off if the motor plug is built in the logical flat orientation. It might work better to build it on the side with some supports, but really, I think I need to redesign this as a two-piece. Unfortunately, my Fusion 3D skills are rusty, and brother Bob has become more of a Blender dude--he's not fond of parametric CAD after doing it for 30 or so years (he says it feels like he's back at work). So I'm spending the time between prints re-learning this stuff. I swear it's harder the second (or maybe fifth) time.

Since the motor of choice has been set (I think it's a great choice) I think a through-bolt design that puts the mast clamp in compression and relies on long 5mm bolts for lateral loads instead of plastic is just a much better approach. So that's where I'm headed.