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 Post subject: Re: Carbon fiber tillers
PostPosted: Tue Nov 02, 2010 8:14 am 
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Location: Rapid City, South Dakota
Surf City Catamarans wrote:
hobie18rich wrote:
Standard Equiptment on the Wildcat.


...and standard or an option on most other catamarans on the planet. I wouldn't even worry about the 'tendon' style connector, go stainless.

Submit it. We'll review it in an official capacity.


Just last week I added a "tendon" style connector to my fiberglass hot stick, and to save weight i'll just go to the bathroom before I go racing.

Now what should I do with the $ I saved...

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 Post subject: Re: Carbon fiber tillers
PostPosted: Tue Nov 02, 2010 8:19 am 
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Location: Detroit, MI
Tom Machette wrote:
. . . to save weight i'll just go to the bathroom before I go racing.

There's a major-scale opportunity for a joke there, but I'm not touching it. :twisted:


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 Post subject: Re: Carbon fiber tillers
PostPosted: Tue Nov 02, 2010 12:05 pm 
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Please don't touch it, Matt. :D

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 Post subject: Re: Carbon fiber tillers
PostPosted: Tue Nov 02, 2010 4:52 pm 
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Location: Northfield Minnesota
The thing about using a lighter tiller isn't about saving weight overall on the boat, its about making cleaner tacks. Swinging any extra weight around makes it harder to keep from wiggling the rudders, which can kill a tack.


Do some dry tacking practice on land where the rudders have basically zero resistance, and watch how much you are flailing the tiller when you swing it around the back. Even with one hand holding the tiller crossbar and braced against the rear beam, it still happens with out a lot of practice.


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 Post subject: Re: Carbon fiber tillers
PostPosted: Tue Nov 02, 2010 5:41 pm 
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Karl Brogger wrote:
The thing about using a lighter tiller isn't about saving weight overall on the boat, its about making cleaner tacks.


Exactly. Try tacking a 17 from wire to wire with roughly 10 feet of tiller extension. It's a lot of swing weight to throw around the back of the boat.

sm


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 Post subject: Re: Carbon fiber tillers
PostPosted: Wed Nov 03, 2010 6:40 am 
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Join the cause, e-mail your HCA NA Chairman and Vice chair and voice your approval.I know Pat Porter (Vice Chairman) has already got the wheels rolling on this issue.
Once we get it past our own HCA NA board, it should be a slam dunk.Pretty hard for the ISAF to not approve when every other ISAF class is allowed to use it.
Pat also in talking to him mentioned he is not certain that the way the Carbon tillers are made (including epoxy and resin) if they are actually conductive.


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 Post subject: Re: Carbon fiber tillers
PostPosted: Wed Nov 03, 2010 3:11 pm 
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mmadge wrote:
Pat also in talking to him mentioned he is not certain that the way the Carbon tillers are made (including epoxy and resin) if they are actually conductive.


You run enough voltage across just about any material and it will conduct. But it would be nice to see some real numbers, which shouldn't be that difficult. Take an X-foot long sample of various tillers (glass, carbon, aluminum) and measure the resistance from end to end.

It also depends on how the particular tiller extension is built. If the fibers are right at the surface and in contact with your hand, then the conductivity to your hand is going to be greater than if there is a coating of epoxy resin over the surface of the tiller providing an insulating barrier.

Of course everything on the boat is potentially soaking wet, so really what difference does it make what the material is if its saturated with water? THe first time you tack, the tiller gets thrown in the water.

sm


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 Post subject: Re: Carbon fiber tillers
PostPosted: Wed Nov 03, 2010 5:34 pm 
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Location: Detroit, MI
Some history on "Why do we have non-conductive tiller extensions in North America?"

In the beginning . . . all Hobies had aluminum tiller extensions. They were OK, but they bent easily, and if bent too far or too many times, they broke. Guaranteed there is not a straight one in existence today.

In the Jan/Feb 1979 HOTLINE, Hobie Cat Co. announced a free tiller extension replacement offer - aluminum tiller extensions would be replaced with the white fiberglass, non-conductive extensions we are all familiar with today. The article mentioned that all new boats, starting with November 1978 production, would come equipped with the non-conductive tillers as standard equipment. The article stated:
Jan/Feb 1979 Hobie HOTLINE wrote:
Our engineering investigations have established one possible deterrent [to power line electrocution] which we feel should be pursued. In a limited number of power line incidents, an added measure of safety can result when a white non-electrical conducting tiller extension is used by the skipper.

The free tiller extension replacement offer, originally set to expire on April 30, 1979 was extended to June 30, 1979.

The new tiller extensions were much more durable than the aluminum ones. They could bend and flex (to a certain degree) and remain straight and undamaged.

In May/Jun 1979 issue of the HOTLINE, there were class rule amendments for the Hobie 18 which included the statement "IT IS RECOMMENDED THAT THE TILLER BE MADE OF A NON-ELECTRICAL CONDUCTIVE MATERIAL" (all caps in the original).

In the 1982 edition of the World Hobie Class Association Racing Rules, Rule 11.1 stated (in part):
Quote:
THE TILLER EXTENSION SHALL BE MADE OF A NON-ELECTRICAL CONDUCTIVE MATERIAL ON ALL NORTH AMERICAN REGION BOATS EFFECTIVE JUNE 1, 1982. THE NON-ELECTRICAL CONDUCTIVE TILLER EXTENSION IS RECOMMENDED ON ALL BOATS WORLDWIDE.
(all caps in the original)
That language has survived (including the all caps, but less the deadline date) in the International Hobie Class Association Class Rules to this day.

Speculation (my own) is that the replacement offer was the result of a litigation settlement, very much like the Comptip that followed a few years later. Only the old-timers at Hobie Cat (Bill Baldwin and maybe Hugh Greenwald) will know for sure.

Some question "Why the tiller extension?" When the mast contacts a power line, the current will seek the easiest path to ground (the water). The pylons are insulated by the hull structure. The path would then be through the tramp frame, through the person holding the tiller extension, to the rudder castings. If the tiller is non-conductive, it breaks that path. That assumes that the boat is relatively static in the water (pylons not immersed).

In reality, everything is wet - often with salt water (a conductive electrolyte) and in all likelihood, everything on the tramp frame would be energized.


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 Post subject: Re: Carbon fiber tillers
PostPosted: Wed Nov 03, 2010 10:06 pm 
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How conductive is a carbon fiber/ epoxy tube?

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 Post subject: Re: Carbon fiber tillers
PostPosted: Thu Nov 04, 2010 4:47 am 
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There's not a straightforward answer to that.

Just for grins, I pulled out my Ohmmeter (Ω) and did some experiments:

A 6" long, bare carbon fiber tow (a strand about 1 mm in diameter) had a resistance of 30.0 - 35.0 Ω. That's pretty conductive.

As a comparison, I held one probe in each hand - my body has an electrical resistance of ~ 40 MΩ - 2 orders of magnitude greater.

I don't have many carbon fiber/epoxy bits lying around, but I did have a 2"x2" plate that I had cut off a Velocitek mount.

Placing the probes on the surface, the reading was Ω - non conductive.

However, when I put the probes into two mounting holes that had been drilled through the plate and contacted the sides of the holes, the resistance dropped to 2 Ω - almost full conductance.

There's a simple answer to this - the epoxy is non conductive; the carbon fiber is conductive. A carbon fiber tiller extension would be non-conductive - until the outer surface is damaged and the fibers are exposed. Then it's conductive.

If you look at any used fiberglass tiller, it will have abrasion damage where it crosses the rear crossbar (on 14s & 16s).

To muddy the waters even more, an elastomer tendon-style connector is non-conductive.


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 Post subject: Re: Carbon fiber tillers
PostPosted: Thu Nov 04, 2010 6:07 am 
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Location: Thunder Bay,On
So by the sounds of things it is going to be very hard to prove it is conductive or not.
Then I would think the whole issue rests on whether (like the Comp tip) this is a liability issue with the Company.Because if it is this is a dead issue.Maybe Matt M. or Greg Thomas could pipe in with there take on that.


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 Post subject: Re: Carbon fiber tillers
PostPosted: Thu Nov 04, 2010 10:13 am 
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Joined: Sun Jul 06, 2008 8:21 am
Posts: 194
Location: St. Helena, CA
CORK BALLS
Simple solution for those that are obsesed about stick conductivity and its already in the catalog on page 21!
FXGRIP kit $16.95 (Cork is non-conductive)
If this fix is still to expensive may I suggest wearing a rubber glove or place an order with me for 1000 Balls and I'm sure I can get the unit cost down to $7.95 or less and you will have a life time supply.

CORK GUY H18's with BALLS

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 Post subject: Re: Carbon fiber tillers
PostPosted: Thu Nov 04, 2010 10:44 am 
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Speaking as a volunteer only and not as the representative of Surf City Catamarans inc....

I'm over the getting shocked scenario. Sure it happened back in the day ( I'm sorry to the affected families), and Hobie got their shorts handed to them, but man, the world is a different place now with regards to power lines and boat launching.

There is not a single other multihull manufacturer today that has changed their design with regard to electrocution. I understand it, but in today's world, I personally think it's silly.

1) The W Cat comes with a Carbon tiller.

2) In the Hobie Catalog there are 3201, 3202, 3203, all "Aluminum Hiking Sticks", which are way more conductive than Carbon/Epoxy. I don't understand how you can sell an "Aluminum Hiking Stick" and say it's "not class legal for racing" right next to it, and expect to be protected. You're still saying that it's OK to use your "Aluminum Hiking Stick", just not for racing. I would think that the racers are a safer market for a conductive tiller extension due to experience. The catalog says the opposite.

3) I can understand the whole arms race thing, which to me is a very valid argument (the only valid argument really). The 16 should remain sort of a bare bones class, with not much change. Really though, the Arriba stick is around $140, the stock around $100, and the Carbon, non extendable sticks are around $200. I have manufactured carbon/kevlar .5 inch sticks for Aclass, and they retailed for around $160. (that was a few years ago). Ronstan could do a custom length run of carbon sticks for us, I'm sure for right around that price.

4) Arguing that the carbon sticks are "non-conductive" isn't the right path to take here. It would take a lab and some serious cash to make the argument valid. If the tillers were found to be non conductive, the class rules would be moot instantaneously.

What is non-conductive? 120 VAC may not travel through a carbon/epoxy tube, and maybe 240V won't, but what about a common transfer line like 4, 13, 26 or 69 Kv? At some point the power will arc through the air, making all of this argument for not. And as brought up, what about salt water?

I'm not an electrician, and only have a rudimentary understanding of how it works.

http://upload.wikimedia.org/wikipedia/commons/4/41/Electricity_grid_simple-_North_America.svg

5) What about Kevlar? Is it conductive? A quick google search revealed mixed results.

6) To reiterate, I think that the 'non-conductive' argument isn't the route to take here. Let's just get over that. If the argument that the tiller should be non-conductive were important, to me it would be more important to me to make the tramp frame, (where you're sitting and has a direct conductive link to the mast. ie. The most likely point of contact with a power line) non conductive. Wasn't that dealt with with the comptip? The tiller and rudder system are isolated electrically from the most likely source of contact by the fiberglass hull. If you do get a shock through the tiller, you either touched a power line with a conductive part of the rudder system, or you're getting shocked through the tramp frame. I can not see a reasonable way to get a shock through just the tiller extension. I'm sure someone could figure out a way to do it.

These are only opinions. I am not an expert. In fact I am an idiot with no right to say what I just said.

Jeremy
Volunteer


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 Post subject: Re: Carbon fiber tillers
PostPosted: Thu Nov 04, 2010 10:51 am 
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7) What about carbon with heat shrink like the new stock tiller? Now that IS non conductive.

Gotta go. Have some manufacturing to do. Who wants to try the first one?

Jeremy
Idiot with opinions.


Last edited by Sail Revolution on Thu Nov 04, 2010 11:44 am, edited 1 time in total.

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 Post subject: Re: Carbon fiber tillers
PostPosted: Thu Nov 04, 2010 11:38 am 
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I guess that makes me an idiot to (which I and most other people already knew).I think your opinon is right on the mark.

BTW $165 for a 96" Carbon Fiber Tiller made by ACME,that includes tendon universal.Ronstand actually sell there's for $153.


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