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 Post subject: rudder shaft
PostPosted: Wed Sep 21, 2016 4:46 pm 
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Joined: Mon Dec 28, 2015 6:58 pm
Posts: 24
did somebody tried a titanium rod for the shaft ?

As it's impossible to find a 19X3MM stainless tube, I think to use a 16mm rod titanium for my new rudder, do you think it is a good solution ?

gilles

GBR226
FRA???


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 Post subject: Re: rudder shaft
PostPosted: Mon Sep 26, 2016 8:32 pm 
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Joined: Mon Dec 28, 2015 6:58 pm
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need some help.

Nobody ?

thanks

gilles


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 Post subject: Re: rudder shaft
PostPosted: Mon Sep 26, 2016 9:23 pm 
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Joined: Mon Sep 12, 2005 7:45 pm
Posts: 727
Location: United Kingdom
I don't know how much experience us folk are going to have had with Titanium.
The rudder I have in front of me now has a 12.5mm stainless steel solid rod shaft and the blade is about 22mm thick. I don't know whether that's typical or not, and I'm not a good enough engineer to translate that into equivalent strength for titanium. That 12.5mm rod has lasted a good few years though.


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 Post subject: Re: rudder shaft
PostPosted: Tue Sep 27, 2016 9:32 pm 
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Joined: Mon Dec 28, 2015 6:58 pm
Posts: 24
thanks for your answer.

I had the same ruder as you...but it's dead.


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 Post subject: Re: rudder shaft
PostPosted: Wed Sep 28, 2016 6:35 pm 
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Joined: Mon Sep 12, 2005 7:45 pm
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Location: United Kingdom
Come on chaps. I'm sure a number of you know far more about this than me... Help out here.

I think all I can add is that if my rudder needed replacing and I just wanted to go sailing I'd do the same again - the SS rod. However if I wanted to experiment Ti sounds interesting and from what (little?) I understand lives better with carbon than s/steel.


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 Post subject: Re: rudder shaft
PostPosted: Thu Sep 29, 2016 1:38 pm 
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Joined: Sat Sep 06, 2003 8:13 pm
Posts: 76
Location: United Kingdom
I haven't had easy access to titanium so haven't tried that. I use 1/2" SS which has always worked for me and I haven't had failures. 12.5mm works for some folk but I've bent that in the past ! I think I can supply 1/2" SS with the 3mm or 5mm rods to run through the shaft and into the rudder blade. I've me a call if I can help.
Tony M.
GBR333
07855 831060


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 Post subject: Re: rudder shaft
PostPosted: Thu Sep 29, 2016 1:55 pm 
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Joined: Thu Jul 17, 2003 10:08 am
Posts: 122
Location: United Kingdom
Afraid I can't add much to this.

You can find a discussion and comparison of the two materials at: http://www.differencebetween.net/object/difference-between-steel-and-titanium/ and at: https://answers.yahoo.com/question/index?qid=20100319171745AAOllge. It sounds like in general, Titanium is likely to be stronger, but it will depend on what alloy of Titanium and what alloy of steel. Titanium is however more inert and therefore likely to give less problems running in Carbon especially in/around salt water.

I would of though that a 19mm titanium rod, being 7mm thicker than is what is normally used here, should be plenty strong enough. As long as you can get it and afford it. A few thoughts though. You need to put something through the rod to stop in turning in the blade. Drilling a titanium rod might be hard work?? Not sure, just a thought.

I am sure others may of tried it, but the only canoe I have seen with Titanium parts was the Orange IC that was brought over by Christian from OZ to UK for 2005 worlds. Called Austrasized (sp?) by Neil Witt, when he bought it, it was later called the 'flying Baked Bean' by Stu Budden that had it next. But I don't know whether the rudder post was Titanium on it, although I remember that other parts were.

We normally feel that 12mm stainless is strong enough, but I have known a few break, including my own, when almost out the Camel Estuary. When it went, it just snapped - no warning, just went, and I didn't like that, so when I built a new one, I really didn't want to use stainless again and built the post from carbon/kevlar. Since then, there have been many dire warnings about the inappropriateness of carbon rod for this use and I guess I would follow advice and not do it again, but on the other hand, it must be over 10 years now since I made it and other than resurfacing it with graphite/epoxy every year so, it appears to be doing fine.

No doubt in my mind that if I had some 19mm Titanium, I would feel more than confident in using it. Go for it and tell us how it goes....

What's the worst that can happen? :-)

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Ed Bremner
IC GBR242
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Classic & Vintage Racing Dinghy Association
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 Post subject: Re: rudder shaft
PostPosted: Thu Sep 29, 2016 9:34 pm 
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Joined: Mon Dec 28, 2015 6:58 pm
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What's the worst that can happen?

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Nothing I hope !

thank for your answer.

gilles (french new IC, old MPS, RS700, RS600 and others...futur AC...with a good rudder!)

cheers


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 Post subject: Re: rudder shaft
PostPosted: Mon Feb 27, 2017 12:11 pm 
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Joined: Fri Dec 22, 2006 10:32 pm
Posts: 466
Location: United Kingdom
Gilles,

You may have solved this but anyway.....

I spent a lot of time messing about with s/s shafts in rudders and found the following;

1/2"/13mm solid is not string enough. It will bend if you stall the rudder at high speed >15knots

We use a 15mm solid carbon tube into the rudder with a 19mm stainless tube fitted over it where it exits with 1.5mm-2mm wall thickness. The stainless is needed for wear and strength at the point where the tube exits the rudder and at the bottom pivot in the boat where there is a huge load (up to 400kg). The stainless only needs to go into the board about 20mm but there needs to plenty of strength built into the blade at this point so overwrap with carbon tape to fit between the rudder skins and heavily score the stainless tube which sits inside the rudder. The 15mm carbon rod is glued into the board down about half way and then put a 10mm tube through the carbon rod near the bottom to stop it twisting. We use a 15mm tube with smaller tubes glued inside and finally a solid core.

Normally this goes between the rudder skins on a new rudder but you can drill into an existing one and then make a hole halfway down to fit the anti-twist peg and then gob the whole lot up with epoxy.

Alternatively we can make you a new one!

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Steve Clarke (UK)
GBR324 "Hells Bells"
GBR338 "Money4Nuffin


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 Post subject: Re: rudder shaft
PostPosted: Mon Feb 27, 2017 5:00 pm 
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Joined: Mon Dec 28, 2015 6:58 pm
Posts: 24
thank you steeve.

I did exactly what you say, I have just to finish the carbon skin of the blade. I hope it will do the job.

Gilles
IC 226
AC 261


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