I hear what you say. It's just that if the guesswork can be reduced, then that saves a bit of time.
I've recently bought a couple of books on boat design on eBay. Will see if that does me any good. I don't have the resources to make a number of different keels, from a length, or bulb mold view, so I'd like to get as close as I can first time.
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Maverick Model Yachting - The Only Way To Go! Secret Alias - Don Leitis
Well let me put it another way? The easiest thing to change on a model yacht is the length of the keel.
now if at your venue there is lots of light winds then you won't see much change in your model's performance, overall. I know at our venue this is the case and in most cases this shortening of the keel is a good thing in general sailing conditions.
Fundimentally though, the difference in a long keel and a shorter keel in CLUB racing should not be that noticable over a range of conditions up to 10 knots, so much so that I have used a Marblehead with a shortened keel (12") that I sail to great advantage in light weather, for some years. By sailing with a shorter keel you have the advantage of using , perhaps a shallow lake closer to your home and so there is a saving on petrol costs etc.
Most things encountered with model yachts is in the light range of wind. Like you sail in (in lots of time) with winds less than 10 knots? When it is really windy you may not want to sail for fear of doing some damage and you have a go on some other day(less windier day). So most of your sailing is done in the wind speed range of 0 to 10 knots, Okay? Now if there is not going to be that much happening with your boat having a shorter keel. Go fit it ,it's more about sucking it and see what happens than doing the mathmatics at the early stage!
No Henry. I want to keep the rig as it is. That is a part of the appeal to me of that particular boat. And I know it can sail in some really rough weather. I would still like it to be able to do that. Hence the need for the extra weight on any shortened keel.
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Maverick Model Yachting - The Only Way To Go! Secret Alias - Don Leitis
I've only got one rig for the 10R and want to keep it, so to go to a shorter keel, I would need to add weight. I just don't know how much.
And it would still meet the objective of not going heavier than an A2/N12. I mean, I think, from memory, I could almost add another couple of Kg to the keel and it would still only be half the weight of an "A". I could handle that.
Like I said, my only problem is knowing how much extra lead I need to add for any given length of keel shortening. And possibly if I need to move the bulb centre a bit further forward, leave it where it is, or move it rearwards a bit.
Damn, it is amazing how little a piece of knowledge is required to make something a huge, major, cataclysmic, problem. Not shore if I spellt that catac... werd wright.
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Maverick Model Yachting - The Only Way To Go! Secret Alias - Don Leitis
Well the job is in front of them to explain it to you?
I wouldn't try myself but let me raise an item here in talking about this subject. Your talking about your ten rater ; What if you used a smaller height on your main rig, with your reduced keel length?
There are a few things we should consider in the height of the rigs , for you can use a tall rig with a short keel in less wind days. Is is not a question that one uses a less tall rig in windier days?
In practice , the size of the rig is about your ability to change it at at any time.
So there is a possibility that you could change keels weights/ depth instead of rigs!
Especially when most water sources comprising lakes, dams, etc., seem to be drying up, or at best, water levels are dramatically reduced.
I continue to be astounded at what sometimes appears to be a sport based on extremely short-term views. And my thinking here, is that this happens because the majority of sailors in this sport are middle aged or older, and many will simply resist the concept of change, simple because it means change, and they will need to adapt to something new, something with which many will not be comfortable with. That's why we need new blood.
Yet I would argue, that by going to a shorter keel, new challenges will arise, renewed interest will arise, in terms of tuning, sailing in a greater variety of venues which might prove testing but which were previously unavailable to the long keeled boats, more convenience of transporting your boat to the water's edge, etc., etc. Maybe it might even be a bit of a leveller in allowing the old boats to match it with the new ones on an equal basis, at least until people get used to the revised handling characteristics that the shorter keeled boats will demand.
Shortening the keels, to allow these competitive boats to sail in a greater variety of venues is something I believe should be encoraged.
One problem I see though is how to shorten the keel but keep the same sailing characteristics of these boats.
I have an old, but fast 10-rater, but I don't get much of a chance to sail her, where I normally sail. I have been thinking about reducing the length of the keel, but am not sure about the calculations required to enable me to do that successfully. I know that if I shorten the keel, I need to add extra weight to the bulb. But how much? And if the existing keel is swept back, where/how do I find the point at which the new heavier bulb should be placed on the shortened keel.
I did actually do a calculation based on length of keel multiplied by weight of bulb to give me a starting figure. I then did a new calculation with a shortened keel, and from there determined the weight of the bulb I would need, to come to the same figure as I had calculated with the original keel.
However, I am not a boat designer, so I don't even know if my concept is sound, never mind the correctness of calculations.
See, how challenging and stimulating can this be?
All we need now, is for someone who has the expertise to explain things like this to a simple soul such as me.
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Maverick Model Yachting - The Only Way To Go! Secret Alias - Don Leitis
