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Semi-Commercial Haka
http://www.hobie.com/forums/viewtopic.php?f=69&t=67112		 Page 1 of 3
Author:  tomcfitz [ Tue Aug 04, 2020 8:46 am ]
Post subject:  Semi-Commercial Haka
I have been fiddling with the idea of developing a haka for myself, but I'm happy to make more of them for you guys here. I have access to marine-grade AL, a laser cutter, press brakes, etc.

My preliminary design is made of 3/16" thickness Aluminum, held onto the boat using some "Quick Fist" clamps (thanks to someone on the FB group for pointing those out!), with a white marine-grade macropoxy finish. I'm looking into putting "Sea Dek" or similar, but depending on price I may have to pass.


I'm about to cut the prototype this week or so, and here are some specs:

- 66" Long, 12" wide
- 3/16" AL should be good to 250 lbs in the center, 1/8" could save some weight but may be flexier. Will protoype 1 of each probably.
- Weight: 16ish lbs a piece, comparable to rotomolded backboards

Cost will end up being around $100-250 depending on sea dek pricing and so on. Hoping to keep it towards the lower end of that range, but I have to have some margin in there in order for my boss to approve me making more than a couple. I don't run the place yet!

Any thoughts? I also have a rotomolding machine, but we'd be looking at $10k in tooling just to get it started, which I don't think is in the cards...

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Author:  tomcfitz [ Tue Aug 04, 2020 12:27 pm ]
Post subject:  Re: Semi-Commercial Haka
Well, did a bit of testing on the slot/bend interaction. I've decided 1/8" is gonna be the way to go, with potentially 1/2" SCH 40 piping in the corners, both to help make the thing more comfortable to carry, but also to add a bit of rigidity. Weight should be down near 11.5lbs at 1/8" thickness, 14.5lbs with the pipe.

I also increased the overall width by 1.75" and the slot widths by .375, since they scraped my knuckles a bit when handling it. The "final product" will be TIG welded, not MIG like this. Just used MIG cause i came across a bored MIG welder before i found a bored TIG guy.


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Author:  stringy [ Tue Aug 04, 2020 2:34 pm ]
Post subject:  Re: Semi-Commercial Haka
Nice work TCF! 8)
I’m looking forward to seeing what you come up with.
I built 3 versions of haka over the 12 years or so I had Islands. If these are for a TI consider a length of 2m (around 79”) as the sweet spot for soloing the TI is sitting opposite the rear footwell. That cantilever also makes it easy going from the rear seat to the haka and back.
Author:  tomcfitz [ Wed Aug 05, 2020 6:51 am ]
Post subject:  Re: Semi-Commercial Haka
They are for the AI, overall length of 66"

I don't think the "quick fists" will support sitting cantilevered behind the akas. They are really just to keep the thing from sliding around, since they only support 25 lbs each. There are heavier duty ones that support a lot more weights, but at 79" long, the AL would have to be 3/16" or even 1/4" thickness to have good rigidity.

I have redesigned it a little bit: Widening the slots as well as adding in the pipe rails. First prototype should be cut and bent in the next couple weeks. New screenshot:

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Author:  mmiller [ Wed Aug 05, 2020 4:00 pm ]
Post subject:  Re: Semi-Commercial Haka
Our engineers have been toying with a Haka bench. Has to reduce in size for shipping or will not work for us.
Author:  tomcfitz [ Wed Aug 05, 2020 4:12 pm ]
Post subject:  Re: Semi-Commercial Haka
Whats the size goal? I can see splitting it in half and using a piano hinge or similar.

I've been thinking about that a bit, since we have hatchbacks, so space is at a premium when we take the boats places. But these should fit on the trailer pretty easily between the boats.

I've also been thinking about table legs for them as well.

Going to have the first prototype next week sometime, so I'll keep this thread up to date.

The nice folks at Marine Mats are working with me too, so hopefully the final version will have nice custom cut foam padding on it too.
Author:  NickW [ Wed Aug 05, 2020 4:25 pm ]
Post subject:  Re: Semi-Commercial Haka
Made some out of White Kiln Dried Pine (lite weight) years ago and spar varnished them, they work really well but they are still too heavy. So I'm all in if ya'll can come up with something strong and light weight for a TI.

Cheers

Nick
Author:  mmiller [ Wed Aug 05, 2020 5:51 pm ]
Post subject:  Re: Semi-Commercial Haka
I'll have to ask shipping. Needs to fit FedEx and hopefully not too much over sized. The costs go up quickly.
Author:  tomcfitz [ Wed Aug 05, 2020 6:25 pm ]
Post subject:  Re: Semi-Commercial Haka
Well, let me know what the criteria are. I'm happy to take some of that into account on this design. Maybe you can get them to send me a new AI and TI for testing, eh? :mrgreen:
Author:  mmiller [ Thu Aug 06, 2020 8:47 am ]
Post subject:  Re: Semi-Commercial Haka
;)
Author:  tomcfitz [ Wed Aug 12, 2020 10:31 am ]
Post subject:  Re: Semi-Commercial Haka
First prototype is cut and bent! I'll be test-fitting it tonight or tomorrow. Looks pretty good! The guys in the shop bent it slightly wrong, and the slots are a bit distorted, but I think it should work pretty well on our trip this weekend!

Image

Image


Final version will be painted white and have "seadek" style foam.
Author:  mmiller [ Wed Aug 12, 2020 11:59 am ]
Post subject:  Re: Semi-Commercial Haka
You can go onto FedEx.com and try dimensions for various rates:

Diameter plus length:

Over Sized rates after 48:

Ground max 108"

Express Max 115"
Author:  tomcfitz [ Wed Aug 12, 2020 12:44 pm ]
Post subject:  Re: Semi-Commercial Haka
Looks like fedex shipping from NC to Seattle would be $100 for one or two of them. Not... great. But it doesn't look like it goes down if they fold in half, which is weird cause then none of the dimensions would be over 40".

Actually it looks like shipping for a single folding one would be a little over $50.

I dont have quick access to UPS quoting, so I can't quote it there, but it seems like they would be easy to ship to dealers along with the boats, since they would both be going freight?
Author:  mmiller [ Wed Aug 12, 2020 1:25 pm ]
Post subject:  Re: Semi-Commercial Haka
Our parts ship FedEx primarily... Only larger stuff goes with Trucks. It is possible, but that is not cheap either. They do not ride free.
Author:  tomcfitz [ Thu Aug 13, 2020 5:49 am ]
Post subject:  Re: Semi-Commercial Haka
More photos I forgot to upload yesterday:

Weight came in at 17.2 pounds, which is pretty close to my estimate of 16 (I ended up going with 3/16")

Image

Here's all 240lbs (ugh) of me standing on it, with essentially no deflection. I think the next one is gonna be 1/8" just to see, cause this thing is SOLID. Just have to refine the mounting system, hopefully get that done this afternoon.

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