Author Topic: Foil Boom  (Read 20019 times)

PonoBill

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Re: Foil Boom
« Reply #15 on: November 09, 2019, 07:16:13 AM »
I doubt it. I considered making a boom end out of thin aluminum. I build a lot of very light aluminum parts, so it wouldn't be much of a challenge. I could certainly reduce the weight of the boom end by more than 50 percent. I build things like aluminum shelf brackets for my motorhome and other goofy projects that weigh a few grams but support 250 pounds--the general design would work well for this. But rationality overcame me and I just butchered one of my existing boom ends.

I reduced the weight of the boom end with some old school hotrod drilling using small holesaws. The thicker girder webs on the plastic is where most of the rigidity is so I took out quite a bit of the plastic in between and also cross-drilled the heavy connector. Dan Gavere did a lot more removal than I did and his is still holding together, but I'd be a little concerned about flex if I went much further. As it is, Ken Winner expressed some doubts about the idea, so I tested the ability to resist flex with a stock boom and my lightened one using a loop of line to the upper fixing point and letting the blade rest on the edge of my workbench. I added weight to the shaft a foot from the boom end and found no measurable (using my primitive rig) difference between stock and lightened.

The lighter boom makes the wing much nicer to use. I don't think it adds anything to solving the fundamental stability problem with the larger duotones but a lighter wing is simply easier to handle in most conditions.

A pretty short jump from here to a boom end. I tested these to the point that they started to buckle. The double-sided one reached a little over 250#. I don't remember what it weighed, probably under 30 grams. I'm sitting here looking at the buckle pattern seeing how I could improve the strength. there goes my morning.


« Last Edit: November 09, 2019, 07:23:24 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.

Keys Sup

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Re: Foil Boom
« Reply #16 on: November 09, 2019, 10:33:52 AM »
Ok standard boom ends.

PonoBill

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Re: Foil Boom
« Reply #17 on: November 09, 2019, 12:12:17 PM »
Here's the swiss cheese boom end:





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.

Keys Sup

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Re: Foil Boom
« Reply #18 on: November 10, 2019, 05:53:38 AM »
Cool! I like the Hot Rod style.

Keys Sup

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Re: Foil Boom
« Reply #19 on: November 13, 2019, 06:41:16 AM »

Looks like Dragonfly is using Admins idea of the handle tracks.

Admin

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Re: Foil Boom
« Reply #20 on: November 14, 2019, 02:22:57 AM »
That is good in that it is selectable and tunable.  Lacking in that they are still using soft handles and that the vertical handles have no room for a hand.  The real beauty would be unlocked if they eliminated the center track.  You could then attach a small, radiused plate (that roughly matched the arc of the strut) with a rigid handle to the two remaining horizontal tracks. That would offer a lot of leverage and an ultra firm connection.   It could also be lighter and more portable than anything existing.  You could attach horizontal handles, vertical roll handles or both.  These handles could have a variety of diameters and lengths to suit any hand size or riding style.  This could also be done very inexpensively.  Offer a stock kit with 2 or 3 molded handles and offer add on's and carbon upgrades for tweakers.  You would only need one handle set for a quiver so individual wing cost would be less.  The stowable size across a quiver would be much less.  The handles could be tool and hardware free using only inflation expansion to secure them.  Riders who wanted a longer bar (at any length) or dual bars could attach those as well using the same tool-free mount plates.  This would be way more rigid and lighter than existing booms for riders that this appeals to and would get rid of the current kludgy attachment systems.  It also works perfectly with the Swing style luff strut which I think we can all agree is amazing.  This is a natural for Wingsurfing.
« Last Edit: November 14, 2019, 03:14:01 AM by Admin »