Geezer foil--back in biz

[Bean]

I would guess, active rudder wing to keep it all level?

[PonoBill]

yup. Unless it turns out that it will weight steer, which I doubt.

[PonoBill]

I settled on through bolting rather than using fin boxes. Might seem like a strange idea, but the crosspiece is intended to go on top of the board, so the lifting force would be trying to rip the fin boxes out vertically--not a strong direction. A Tuttle might have worked, but through bolting is quick and easy. I used long lamp nipples, coated them with water-mixed gorilla glue, and screwed them into place. Strong and leakproof. I've used this method before when I wanted to mount a gopro underwater and be able to aim it as I paddled. My ventral sailfin also used this.

I was going to tow it behind a boat today, but got busy with other stuff, including putting a ventral fin into my Blackfish. I'll be fin testing tomorrow, which reminds me, I need to find my speedcoach and charge it.

[LaPerouseBay]

Ok, I'll bite.

PB, that's the biggest pile of shit you have ever created. 

A for effort.  Sounds like a complex project. 

But, but...  those things are not symmetric!

Were you an unruly child? 

[PonoBill]

Yeah, it's a bit rough. The wings are actually closer than they look in the pictures to being symmetric. they started off as two sides of a glider wing and I reinforced them with aluminum to keep them from distorting while vacuum bagging. I don't think the biggest problem is going to be lack of symmetry, it's flex. I might have to hit the reset button. I think my shortcut of using a skateboard base as the bridge is just not going to work. But I'm going to tie some weights on and drag it around behind a boat. Was going to do it tomorrow, but other priorities intervene. Next week is pretty open, so I'm hoping I can get some testing done and at least decide if I tear it down and do something different or press on.

This is the low lift setting--if my calculations are right, about 190 pounds of lift. The numbers come out a little different every time I measure, but that's because the foil is angled steeply.  This angle makes the symmetry look a bit better.

[stoneaxe]

I told him on FB he's going to lose a nut to that thing.....symmetric or not fugly is the only word. I know you're doing 15 projects at once as usual but this one looks like it has far more potential for body damage than usual....and that is saying something with you bro.

[supuk]

What's lifting the rear of the board? Look interesting and not a million miles away from my next foil build.

When I put my first foil in the water for testing you could get it to rise just by giving it a quick push no need even for a boat

[PonoBill]

Nothing lifting the tail--yet. I want to test just lifting the nose. I'll do a T fin to get the tail up, probably just attach a small, low aspect foil to a fin.

Nuts are over-rated.

[PonoBill]

Ready to test. Yes, there will be foam and duct tape.





Bolting it down tightened up the brace a bit, but it's still kind of boingy. Who knows, maybe that's a good thing. Boingy foils might be an exciting new trend. #boingyfoilfails #areyourfoilsboingy?!?

[clay]

Nice work.  I appreciate the function over form test approach, as I loathe to make something pretty until I know if it works or not.

Is that a Specialized Fuze electric bike conversion I see in the background?  I ask because I had my old e-bike stolen this year and upgraded to the Fuse in the same color with a Bafang HD, loving it and the XXL frame big time.  How do you like yours?

[PonoBill]

I build all my electric bikes. there's threads here on the zone about them. I'm not sure which bike you are looking at since there's two--one is a recumbent trike with a mid drive. 1200 watts more or less. Mostly homebrew. The other (which is what I suspect you are talking about) is a Trek that I recently built using a Bafang BBSHD motor. I built my own battery for it, but it's been acting up. Not what you want with a kilowatt of Li poly batteries between your legs, so while I figure it out there's a Lunacycle battery powering it.

I like the Trek a lot, though it still has some teething pains that some of my simpler bikes didn't have. I don't have the gearing quite right, and the drive sprocket doesn't center on the derailleur, so the lowest two gears aren't really usable, but it's a ten speed rear hub, so that's not such a big deal. I recently did a 68 mile round trip ride with it, with just a quick partial charge between legs, and didn't spare the ponies. I needed to get back to the place that was servicing my truck, so I pushed it hard on several long climbs. Made it (barely).

[Adolfo]

Hi Bill.
Nice work!
I like your way of thinking out of the box.
English is not my mother language, so please excuse if my writing is not accurate.

If you don’t mind, I would like to give you a heads up from a novice kite foiler: the most usual fall for beginners is when the foil gets out of the water. The foil cavitates, looses lift, the nose of the board hits the water, and you fly over the bars. I understand that with your design that should be more gradual than with the foils we use, but anyway please be ready to fall forward. Those screws don’t look  like a good place to fall in. And with the foils extending so much at the sides of the board you can’t fall to the sides either.

Another consideration is the foil placement. In the ‘normal’ foils your weight is supposed to be centered over the lifting wing. In yours, you will be standing further back, but if you go to much to the back, you will sink the tail. It’s difficult to say looking at the picture, and not knowing where you will stand on the board, but wont that foil get in the way of the paddle?
How do you plan to put your weight over the foil and be able to paddle with those wings extending to the sides?

I’m very curious to see how your geezer foil works. It can be a game changer.

[yugi]

^^ good point
but I'm guessing the bolts will be taken care of with the "Yes, there will be foam and duct tape. " he mentions.

I just wonder why so big! I like the concept and envisioned same but much (much!) smaller since the purpose of these is just to help a bit with initial lift. I imagine excessive lift up front will just behave like a wheelie. Excessive wheelie will drag the tail which becomes a handbrake. Also since just as assist was imagining super high aspect to have minimal drag.

Sure look forward to hear what it does.

[clay]

yeah those bolts sticking up had me imagining a crucifixion upon falling, I also figured Bill had a plan to address that.

Looking forward to the ride report.   Here it is the end of the windy season and we finally get some big winds in the bay area, so I have DW on the brain.

Yeah must be your Trek, wow 68 miles all under power that's impressive.  I'm told mine will do about 30 and yet to find out how far it will go.  My bike looks a lot like yours:

[PonoBill]

Nice!! Yeah, you have about half the battery size that I do. I've become used to long e-bike rides. Friends here in Hood river were giving me grief for my eBikes until they realized my typical ride is 50 miles, and takes about the same amount of time as their 25 mile rides. the serious lycra dudes go as far or further, but they spend all day at it. 

With my crap knee the eBike is fabulous, and the trike is ideal for those days when I can't afford to fall (like just prior to getting my knee lubed or post surgery).

Ready for testing and approved (more or less) by the safety patrol (Diane).