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Author Topic: What is that ARTR Yacht in this months MM?  (Read 10074 times)

KitS

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Re: What is that ARTR Yacht in this months MM?
« Reply #25 on: August 15, 2009, 02:19:05 AM »

Today I made a few mods to the Volvo, added a transom plug so I can drain the bilges after sailing and installed a new eyelet on the clew of the mainsail. The eyelet is about 3/4" forward of the existing one and about 1/4" liower, this means I can haul the foot of the sail tighter and minimise the flapping that it exhibited beforehand. My theory is that the mainsail just stopped working under some conditions, slowing the boat and allowing the jib to take charge.

It seems to have worked anyway, the boat is easier to control in gusty winds and it's downwind performance is much improved. What it won't do is turn through the wind very well when tacking. Quite often I found the boat in irons when sailing this evening, odd when it has TWO rudders.

The drain plug worked a treat, good thing too considering the amount of water that drained out of it!
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Kit

Robert Davies

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Re: What is that ARTR Yacht in this months MM?
« Reply #26 on: August 19, 2009, 12:54:05 AM »

Quite often I found the boat in irons when sailing this evening, odd when it has TWO rudders.

Water doesn't scale down....

I suspect - but can't prove - that the water flow from one rudder is possibly 'stalling' the water flow from the other rudder, and vice versa. So in effect I'm suggesting that instead of two sharp rudders slicing through the water, it amounts to pulling one very wide and blunt one with little or no no directional presence. This effect will only generate (probably) at certain angles of attack of the rudder.

Or I could be talking bilge....

-Rob

ps Nice looking boat, but that main sail doesn't look terribly effective as you've surmised.
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KitS

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Re: What is that ARTR Yacht in this months MM?
« Reply #27 on: August 19, 2009, 10:20:03 AM »

Rob,

I like the theory, you could well be right about the 'wide blunt rudder' business.

I must admit my technique when tacking is to just heave the stick over as far as it will go in an effort to turn the boat through the wind as fast as possible. Perhaps a litttle more finesse is called for and I ought to ease the helm over, which may alleviate the 'stalled rudder' syndrome? I'll try that next time.

In the meanwhile I'm changing the Rx to 40Mhz as there's a couple of kids who 'drive' (the word being used in its WIDEST possible sense...) some buggies in the park where I sail, and they hadn't a clue what I was talking about when I asked them what frequency they were on. As it turned out one of their sets was on blue, and the Volvo is on green, a tad too close for my liking, thus the change to 40 Mhz.
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Kit

Tester

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Re: What is that ARTR Yacht in this months MM?
« Reply #28 on: August 19, 2009, 12:19:42 PM »

One thing which might explain the sluggish turns is the vertical angle of the rudders. On big boats with two rudders they are optimized with the angle of heel to get the blade down into the water, thus the windward rudder can be almost out of the water and has little effect.

If your rudders are vertical to the hull you may get the symptoms you describe.
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KitS

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Re: What is that ARTR Yacht in this months MM?
« Reply #29 on: August 19, 2009, 03:28:51 PM »

Yes, they surely are vertical. An interesting thought that, and I've found a few photos on the Net that show canted rudders as you describe.

Quite how I'd modify the Volvo though I'm not sure. The rudder shafts were presumably bonded to the lower hull before the deck moulding was added, as their centre lines are outboard of the small access hatch but about 0.5" and they'd be the devil to get at, although not impossible hopefully. I'll think about that mod when I get back from holiday.
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Kit

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Re: What is that ARTR Yacht in this months MM?
« Reply #30 on: August 26, 2010, 09:40:46 PM »

Can the mast/sail be taken down easily for transporting?

Thanks
Chris
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KitS

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Re: What is that ARTR Yacht in this months MM?
« Reply #31 on: August 27, 2010, 09:53:06 AM »

Chris,

Can the mast/sail be taken down easily for transporting?

Depends what you mean by 'easily'......

You need to loosen and un-hook the shrouds, jib fore-stay and the main backstays, which isn't too difficult, but you lose any adjustments you've made to tune the boat of course. The biggest pain is casting off the jib and main sheets, which are attached half way along the respective booms by winding them around cleats. It's not difficult actually un-doing them, or putting them back on again, but getting the main adjusted to the winch, and relative to the jib setting again means re-tuning the whole boat.

After doing that the first time I've left it masted and sailed as it will go in my car OK fully rigged. I have an old model Zafira and it fits between the front and back seats, angled back so the masthead clears the roof. I've also carried it laid it on its side on top of the luggage bay blind and other luggage, with the middle seats pushed all the way forward. It travelled all the way to the Isle of Man like that without any problems, with the bulb up against the back of the middle seats.
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Kit
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