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PostPosted: Fri Dec 06, 2013 6:28 pm 
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proyak :
That is one of the best ideas I have seen so far.
The trick to implementing the polycarbonate is to transfer as much of the force as possible to the AKA bars, both downward and inward (yes inward). Basically whatever attachment you use will need to prevent the Lexan from getting shorter. (( yes I said shorter),,,when it flexes downward from you sitting on it in the middle, it also gets shorter. If you can prevent it from getting shorter by attaching it to the AKA bars, it has no where to go (it won't be able to flex beyond small amount (just like the tramps or a tight rope). By doing this you are converting the force from bending force, to tensile strength (trying to pull the plastic longer in a linear direction to the plastic (lengthways vs sideways). Think of it like a very tight rope strung between two trees, if you can get it tight enough, you can walk across it like Nick Wallenda does (he's a tight rope guy who lives here in Sarasota).
For example if you use 90 degree angle aluminum (what I would use) you need to have as many attachment points to the aluminum as possible to spread out the force to as large an area as possible in the plastic (example lots of bolts with large washers).
Once you have the side force solved, the rest is easy, you only need to prevent the HAKA from raising up on the AKA bars during use, a couple well placed bungies will take care of that.
If you do it like I describe you should not need any additional re-enforcement. The tensile strength of PC is huge (like 20 times that of wood). As long as you have the force contained and the load points spread out, you should be able to jump on the thing like a trampoline in the middle (within reason), of course this does not mean the AKA bars wont bend and possibly break, since the AKA bars are actually what is taking all the force, by design.
Let us know where you got the storm shutters, and how much they are, I would love to have clear see through HAKA's, I will definitely build something now. I've been holding off looking for the best idea (I think you may have found it). Lightweight, strong, and see through, Awesome....

Hope this helps

Cool idea
Bob

Once your done and when your out on the water just watch out for flying 2x4's coming at you at 150 mph (that's how they test those shutters), the HAKA will survive, but the splinters from the flying 2x4 might break something else ( LOL).


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PostPosted: Fri Dec 06, 2013 7:23 pm 
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proyak :
Actually thinking about it a little more, the AKA bars will not be able to withstand the sideward force without a little help.
You will then need to take a bar (or two) of 3 /16" (or maybe 1/4") x 1" aluminum and trap it in between the two AKA bars (it will be about 4 ft long). You should be able to attach the aluminum to the lexan with about a dozen flat head screws to the underside of the PC sheet on one of the angled walls, spread equally along the length.
What the aluminum does is convert the bending force to compression force onto the ends of the aluminum bar (the force trying to pull the AKA's together when you sit in the middle). If the aluminum bar were not screwed to the lexan it would just bend, the dozen or so attachment points prevent the bar from bending (just like the sheeting on the outside of your house strengthens the 2x4 that hold the house up and prevents them from bending, (your house is held up by the compression force on the ends of the 2x4's).
If you can screw the aluminum bar on the underside of the one of the angled rows in the PC (about 2-3 inches above the point of force (C/L of AKA bar)), the leverage will be much better (less bending).
You may have to create a pillow block or something to get from the aluminum bar down to the inside edge of the AKA bars (at the centerline of the bars). You are actually creating a simple truss using leverage that should be able to handle the weight and load.
Now I'm regretting responding at all, didn't think it would take so much explaining.... LOL

Bob


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PostPosted: Sat Dec 07, 2013 1:55 am 
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Proyaks idea has got me thinking as well Bob. Polycarb is such a great product. Being able to bend 3mm thick polycarb at 90 deg with a 2mm internal radius without cracking, makes it so versatile. I used it for my splitter ( spray shield ) and the strength and flex was ideal for the job.

Image

I'd like to bend up 2 channels out of the stuff. 1 about 300x56, the other 284x53. Turn the first one with flanges down and place it on top of the other one with flanges up. Slide 2 / 50x50 aluminium square sections inside and push them to the sides and pop rivet them all together. It's not a priority but now the idea will always be in the back of my mind until I give it a go. :roll:

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PostPosted: Sat Dec 07, 2013 5:02 am 
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Location: Pompano Beach, FL
fusioneng wrote:
proyak :
Actually thinking about it a little more, ....
........................................
Now I'm regretting responding at all, didn't think it would take so much explaining.... LOL
Bob


Bob,
Your beautiful mind has drawn me into very deep waters! God has blessed you with such a wonderful gift and I'm appreciative of your sophisticated solutions. However another brilliant mind has something to contribute to this thread;

"Any intelligent person can make things bigger, more complex, and more violent. It takes a touch of genius -- and a lot of courage -- to move in the opposite direction." (A. Einstein)

Well Bob, and other convivial shipmates, I'm going to keep it simple, I've ordered 2 spine boards from eBay today - only $100 each with free shipping!

When not fishing alone 3 miles offshore for huge pelagics, I also intend to provide Intracoastal Waterway cruises for friends and family here in South Florida, so I'm also adding first class seating, a couple of West Marine's - Go-Anywhere Seat 2

ALL ABOARD!

.....><>...........><>...........><>...........><>...........><>...........><>...........><>......

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PostPosted: Sat Dec 07, 2013 6:09 am 
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Location: sarasota,fl
Proyak:
Actually the attachment method I discribed in the first part should work on the spine boards as well without needing the second part. Allowing the spine boards to carry more weight than the original design.
We have often taken 3-4 people out on our TI ( only in safe water)
Send us pics when done.
Bob


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PostPosted: Sat Dec 07, 2013 12:20 pm 
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Location: Riverside, S. California, USA
There seem to be lots of workable solution for the deck of Hakas.
I think the development should center on the attachments.
Here is a list, hereafter modestly called the "Beebrain standards" of the ideal design features of an attachment. Some of these may not be important to everyone, some contradict each other to some extent, but they provide a basis for comparison and discussion

•1) Made of inexpensive materials and constructed with common tools and skills
•2) Light in weight, and strong enough for the loads involved
•3) Not corrode in seawater, and not damage amas
•4) Not require modification of the stock Hobie boat
•5) Resist being lifted and moved sternward by wave action (as argued by Chekika)
•6) Fit both TI and AI (and various TI3 positions)
•7) Usable with or without tramps in place
•8) Allow akas to fold with minimal or no re-rigging (see Aussieonyak and others)
•9) Quickly removed and replaced, and moved outboard and inboard
•10) Stabilize amas when in place, resist unexpected folding (argued by Nohuhu)
•11) Adaptable to a variety of Haka decking materials
•12) Contribute to use of Haka as a camp/pitstop table (as designed by CaptChaos and Chekika)

My current idea toward many of these goals goes something like this
Forward: a single sturdy padded hook, similar to but wider than Stringy's, shown below: Image
BUT with a single attachment bolt to the deck, designed for rotation, to allow folding of the ama when the rear is free.
--This satisfies nearly all of the Beebrain Standards, except compromising on #10.
Rear:This is harder. Possiblity 1: Dual bungie strap-downs on corners
--This may be more rigging than some solutions for #8 and #9, but helps with #10, by making a rigid triangle with the front mount.
Possibility 2: tube clips or split PVC, possibly with hold down bungie.
--This would require dual setup for Beebrain Standard #6, would be weaker for #10, since then both front and back could slide more.
Neither of these contribute to #12, (my Hakas follow Chekika's design, and I use this feature.), but separate fittings for this purpose would be easy to implement (though maybe not as wide, thus stable as Chekika's design allows.
I am waiting for feedback to improve these ideas before I make a new set of Haka attachments.


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PostPosted: Sat Dec 07, 2013 6:50 pm 
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Location: Pompano Beach, FL
fusioneng wrote:
proyak :
That is one of the best ideas I have seen so far.
................
Let us know where you got the storm shutters, and how much they are, I would love to have clear see through HAKA's, I will definitely build something now. I've been holding off looking for the best idea (I think you may have found it). Lightweight, strong, and see through, Awesome....
Hope this helps
Cool idea
Bob


Bob,
A year ago I bought a huge stack of Lexan shutters (various lengths for 14 windows) from a guy on Craig's List. I've recently sold off most of them, but if you want a couple, come over and get them. This will be my Christmas gift to you!

Image
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Last edited by proyak on Sun Dec 08, 2013 2:58 pm, edited 1 time in total.

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PostPosted: Sun Dec 08, 2013 6:16 am 
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Location: Fairfax, CA USA
Beebrain,

How about those gigantic coated wire tie things?
I have been using them for all sorts of attachments, and used them in place of bungies prior to going to clips and rail
blaza.

http://www.westmarine.com/webapp/wcs/st ... fgod5ykABw


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PostPosted: Sun Dec 08, 2013 7:51 pm 
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Location: Kailua 96734
Great idea. Y'all can use thick gauge insulated electrical wire also. Plumbers use this to secure and support copper pipes.

Still, bungees rock. :mrgreen:


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PostPosted: Mon Dec 09, 2013 10:55 am 
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Location: Lakeland and Anna Maria Island, FL
I just used my spine board hakas for my first camping trip on the AI this past weekend. I really do like them. Sat on them only to fish and did not yet try standing on them. I secured them with the cam buckle straps - two on each haka - and had pieces of pool noodle on the aka. * Worked great! Still, I will be keeping my eyes open for any lighter weight solutions that I don't have to build or tinker with very much.

* note: I ended up buying the spine boards with the "pins" in them and was glad that I did. Those pins make using bungees and straps much, much easier!


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PostPosted: Mon Dec 09, 2013 11:06 am 
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Location: Kailua 96734
Picts?


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PostPosted: Mon Dec 09, 2013 12:06 pm 
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Location: Lakeland and Anna Maria Island, FL
NOHUHU wrote:
Picts?


Photos of mine? They are just spine boards. This is not what you are after but it's all I have right now. You can see the "pins." I believe Chekika took a photo of me sailing yesterday with the hakas loaded down with gear. For the fashion conscious, it was critical to have hakas that matched perfectly with my AI and sail....

Image

Image


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PostPosted: Mon Dec 09, 2013 2:00 pm 
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Location: Kailua 96734
Those look good. I was hoping for action shots of the Haka.

Maybe you could set up that scene in your living room? :lol:


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PostPosted: Mon Dec 09, 2013 4:18 pm 
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Location: Lakeland and Anna Maria Island, FL
NOHUHU wrote:
Those look good. I was hoping for action shots of the Haka.

Maybe you could set up that scene in your living room? :lol:



I just found this "action shot" on my iPhone. Aren't you impressed with the huge waves and my speed? Hakas really are useful and these spine boards don't seem to need any maintenance. I am grateful to you for getting this thread started. Maybe one day I'll actually be brave enough to hike out on one while sailing in 15 mph winds.

Finding a better solution than the noodle pieces for between the haka and aka is my next quest. The noodles won't last long enough. I tried the clear PVC, which fits very nicely, but I really like the way the noodle squishes down and seems to assist with pulling the cam straps tight. Of course the noodle pieces are cheap and easy to replace.

btw - Living room sailing can be very dangerous. I don't recommend it for many people.


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PostPosted: Mon Dec 09, 2013 4:29 pm 
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Location: Kailua 96734
Yeah, Hobie should add a "Ceiling Fan" warning label next to the one for "Power Lines". :lol:

Yer welcome Terry. Now git your Okole out on those boards and enjoy! Yer gonna love um - I guarantee it.


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