anyone have crab claw on a tiki 38?

[clif high]

just received the tiki 38 plans. My thought is to go to crab claw for a bunch of reasons. Anyone else using crab on tiki 38? If so, how large is your sail (s)? and what type and length of mast. My plan is carbon fiber mast, unstayed.  Thanks. Starting the build now with cleaning out boat shed, and completing a tiki 21. Will put a crab on it as well, and take photos' when we get it out (hopefully later this summer).

 

[Axel]

Beat and Beatriz on Aluna have a crab claw. She sails beautifully, currently in the pacific. Blog at

a href="http://web.mac.com/mobeyprod/Alunatheboat/Welcome.html>" target="_blank">http://web.mac.com/mobeyprod/Alunatheboat/Welcome.html>;

[Ron Hall]

Clif,

Welcome to the start of a wonderful and strange adventure. Not having sailed a crab-claw version, I can't help you on its merits relative to the standard rig. My one thought is that if you contemplate sailing in areas where the wind is generally below ten knots, don't reduce the total sail area on the boat below the plans. Dave Vinney added one meter to his masts, and the boat does better in lighter air, particularly upwind.

My second thought is that any deviation from the plans will cost you more in terms of time (and usually money) than you anticipated. Features on the boat are tied together in ways that are not always obvious, and changes have a way of rippling through the boat in unexpected ways. And changing the rig will definitely ripple throughout the build, and you will have to reengineer things as you go, although building on Beat's experience might solve some problems.

You have a lot of enthusiasm and ideas and energy now, and I think I speak for most of the builders when I say that you will need all of that and more before you are done, so adding a major engineering job (where you have to invent solutions to big problems) will be a big hill coming at the end of the long process of building. If you want the crab-claw rig and have good reasons for changing, go ahead, but recognize that it will take additional time and energy and resources. Suggest you put off the decision as long as you can so you can see how the build is going.

 

In any case, best of luck, and keep asking questions. I always found the forum helpful, even if I then went off and did something completely different.

 

Ron

[clif high]

Look, i have a tiki 21 now, just hulls and beams, and will finish it out as test bed for crab claw. Have experience sailing the crab on my 25 foot umiak. It beats any other rig i  have ever come across. Second is perhaps a well balanced lug rig. But anyway, i will use the 21 footer to size the crab appropriately, and merely transfer the rig proportionally to the 38.  Will likely go dual mast. Willl use vacuum bagging to create carbon fiber collars/clamps that will grab and hold the carbon fiber masts. Am currently engineering and testing the new form of pincer rigging that i use to whip the sail around the mast on the umiak. It is a much better use of the crab claw to have its pincer out in front of the mast. Mostly i am using the mast on the umiak as the crane in a crane/sprit rig as one may see in some of the whangka of polynesian. Works great. Sooo.....not an issue guys. Yes, tons of work. But, i have built 9 boats in the last 12 years, this 38 will likely be my last, and we will make it into art as it is constructed, but in the meantime, i will sail and photo the 21 with a smaller version of the crab claw rig anticipated on the 38.

 

Also note that the collar, and unstayed carbon fiber mast/crane do remove all standing rigging from the equation. Am i to understand that the structure of the tiki 38 requires the stays on the masts to be structurally sound? Is there so much flex that they require the extra strengthening provided by the dynamic tension on the stays?

 

Starting to worry about my decision here. Any unstayed tiki's out there?

clif

 

[Tom Vogt]

I also thought of Beat's Aluna. As to those who tell you to slow down. I think asking questions now and trying to figure things out early or atleast having an idea is a good way to go in respects to awareness, notions, possibilities and such

[Omar M. Rashash]

There was a Tiki 38 with a crab claw rig at this years Wharram Hui in Islamorada. IIRC, it had a stayed aluminum mast with a carbon fiber gaff. The welds on the original aluminum gaff had failed.

Omar

 Found them- Brendon & Aleisa

[Tom Vogt]

Well, I have searched and searched, as well as, ssending out emails asking about the CC rig like what was put on Beat's Aluna to no avail. Junk rigs have groups conversing and basic construction layouts. It seems as those who currently are using the CC rig on larger vessels either have not can not or will not comment or answer questions in regards to their rigs. I now will send questions to the owners of Wakatiatea and maybe try my hand at getting answers on some proa sites.
If anyone has info on the build of these rigs ...material usedand such please contact me
Thanks
Tom Vogt

[Peter Scandling]

Tom

I have also tried to locate info about CC rigs.  It seems that it is somewhat of a closed shop.  It might be worth contacting James Wharram Designs to see if they can provide a few more answers.  I tried to discuss it with Hans Klaar but was not deemed 'interesting enough'!!

Any info you do find would be interesting to many people here.

Good luck

Cheers

Peter

[Alex]

Wakataitea has posted full diagrams etc of his rig in the crabclaw group on this site.

You'd then have to scale it down for the t38 and keep the centre of effort relative to the original Wharram design?

[wakataitea]

hey guys... we are buissy sailing. with our CC rigg. hans just arrived in the Arzores islands again. we are in knysna south africa and having fun here... we stay here till january and then we go on again... to where???? who knows...smile...
we had some articles published in multihull magazines. or have a look on our web... here in plenty of info about CC rigg. wharram can or will not help much i guess. they are buissy with other stuff.
ok, do it and go sailing... the rigg works...
PS: it is better to copy a good idea then to invent a bad one..... haha...
have fun
hans

[Scott Veirs]

Hey Clif,

Did you ever finish that Tiki 21 and try a crab claw on it?  Here's a post with performance data from my Tiki 21 with the 13m^2 crab claw suggested by Wharram for the 21.  Would love to know if you've found good ways to improve upwind performance, particularly in light air...

http://econscience.org/tiki/2015/02/15/performance-of-a-bamboo-poly...

Cheers,

Scott in Seattle