Author Topic: New Hobby  (Read 4300 times)

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Offline geh458

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New Hobby
« on: December 16, 2014, 12:21:43 PM »
Since my plan of building and racing an LSR vehicle doesn't appear to be happening anytime soon, I started a new hobby

I've started racing R/C Sailboats.  The first boat is a Soling 1M.  It's 1 meter long, and the only thing that is not restricted is the interior parts and hardware.  Otherwise, they are all the same, with a minimum weight of 10#.  Mine came in at 10# 7oz, not the lightest, but not the heaviest in the the local club.
Gifford Hawn

Vintage Sports Car Racer looking to convert.......

Offline tortoise

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Re: New Hobby
« Reply #1 on: December 16, 2014, 12:35:57 PM »
Pretty boat.

So to be most competitive, you should be right at 10 pounds, and with as much of that weight as possible at the bottom of the keel, right?

Offline geh458

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Re: New Hobby
« Reply #2 on: December 16, 2014, 12:50:09 PM »
That is correct.  I was shooting for a keel weight of 6.25#, but ended up at 6.8#.  I miscalculated the weight of the epoxy that gets mixed with the lead shot.  The next boat will be lighter.  Being a little heavy is not that much of a handicap, while it might be a slower accelerating in a lite breeze, it will keep its momentum longer when that breeze get even less.
Gifford Hawn

Vintage Sports Car Racer looking to convert.......

Offline tauruck

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Re: New Hobby
« Reply #3 on: December 16, 2014, 12:58:48 PM »
Cool hobby Gifford. :cheers:

Offline JimL

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Re: New Hobby
« Reply #4 on: December 18, 2014, 06:43:18 PM »
Pretty boat, and in the spirit of all Land Speed Racers, talk about the rules. :wink:  For instance, is that a bolt on keel?  Is a bolt on keel allowed?

In light air, bow down reduces the wetted area.  Keel ballast higher lets the boat heel a little more in light air, low speed races, which keeps the boom from pumping so much against the weight of the sheets and hardware.  That keeps the airflow smoother over the back of the mainsail which gives a significant speed advantage when your race turns into a "groaner".

Sailboat racing is like land speed racing where the aero tricks, weight location, and grip count for a LOT!

So.....can you use switchable keels? :evil:  or can you make ballast plugs for your keel, where weight is "low and aft" for windy days, and "high and forward" for very light air?

Have fun,
JimL
ex 'Santana 20' and 'International Star' racing
1978 Nebraska-Colorado Governors Cup overall win

Offline geh458

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Re: New Hobby
« Reply #5 on: December 18, 2014, 07:09:18 PM »
Jim,

Yes, the keel can be removable, in fact a lot of guys do it, makes it easier to ship it if you should need to transport it that way.  I choose to have a fixed keel.  With a removable keel you get the chance for water to enter the hull if it's not sealed well.  I suppose if one had a removable keel, they could have several with different weights.  But remember, the Soling 1M class has a minimum weight of 10#, and keep in mind, they say lighter is faster.  As for plugs for the keel weight, that's not allowed.  In this class the keel must be filled with #8 or #9 lead shot, and epoxy.  As for weight distribution, about the only thing that can be moved, is the location of the battery pack for the receiver & servos.  But in my case, my battery only weighs 4.3oz, not much to move around, and the weight does need to be as close to the center of the boat, and as low as possible.
Gifford Hawn

Vintage Sports Car Racer looking to convert.......

Offline JimL

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Re: New Hobby
« Reply #6 on: December 19, 2014, 12:49:33 AM »
I was thinking in terms of the location of the weight in the keel fin.  I bet the fast guys travel with keels that are all equal weight, but equal in different ways.

In heavy air, you need more rearward weight bias to keep the active waterline as long as possible.  Your maximum speed is about (1.5 x square root of waterline length, in feet, = x Knots.)  That tall main drives her onto her nose shortening the waterline length, and results in weather helm as she heels, and at that point the rudder is half "steering" and the other half "speed brake".  Probaby stuff you already know....mostly I'm enjoying old memories popping up.  I really enjoyed racing 2 and 3 man keelboats.

At Bonneville, everyone says the answer to more speed is always "change the cam".  In sailboats its always "put on new sails".  What a coincidence that they are both your air-managers.

Good luck!
JimL

PS... I couldnt resist doing the math.  It looks like your waterline length is about 3 feet.  That would be 2.5981 Knots max speed, by the standard formula.  If your boat drives the nose down (lifting the stern) enough to shorten the waterline by 2", max speed becomes 2.3479 Knots.  Thats over 9% slower max speed in high wind.  The real working difference will be only about a fourth of that, but it still can leave you pretty far behind if the other guys are using setups to take advantage of your rules.  I just read them and there is a lot of room for this kind of stuff, which means the smart guys wrote the rules...so they can.
« Last Edit: December 19, 2014, 01:11:44 AM by JimL »

Offline geh458

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Re: New Hobby
« Reply #7 on: December 22, 2014, 12:16:23 PM »
Jim, one of the many class restrictions is keel location.  The leading edge of the keel where it meets the hull is set at 16" from the bow, no more, no less.
Gifford Hawn

Vintage Sports Car Racer looking to convert.......

Offline JimL

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Re: New Hobby
« Reply #8 on: December 22, 2014, 05:28:34 PM »
I sent you a PM about one-design keel stuff, and other one-design rules.  Racing sailboats gets as complicated as LSR, I'm afraid. :lol:

Mans gotta' have a hobby!  Thats the only way the ladies keep their sanity, I hear....make sure her man has a hobby.

Regards, JimL

Offline kiwi belly tank

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Re: New Hobby
« Reply #9 on: December 23, 2014, 05:47:26 PM »
Google the name Ben Lexcen, might help you look outside the box.
  Sid.

Offline JimL

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Re: New Hobby
« Reply #10 on: December 24, 2014, 01:14:08 AM »
Also Alan Payne.  I had one of his boats in my early years of sailing...another Aussie designer who was forward thinking.

Fascinating sport, but can be an awful lot of hard work before you even get out on a cold and windy water....to do more hard work, while you are soaked to the skin. :-P

JimL
« Last Edit: December 24, 2014, 01:18:53 AM by JimL »