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Author Topic: Glyn Guest's "Emily May"  (Read 7238 times)

CERES

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Glyn Guest's "Emily May"
« on: November 14, 2009, 10:25:25 am »

 :-)Hi,
I built this stand alone model as published in the Model Boats but I increased tha plan size by approx 20% to get a 600mm plus length.
In doing this I accept that additional ballast would have to be installed which I have done. My model sits in the water well above the water line but still rolls considerably so much so that if it is windy I don't sail it.
It has been suggested that I install a Keel to compensate which I am going to do but what depth of keel would I need 30mm?. Or could it be that my superstructure, Masts & Cranes are to tall although they have been made to the size on the drawing. Again are these sizes acturate to size & depth of the hull.
If anybody has any suggestions I would be grateful if you could let me know.
Thanks a lot,
Bernard.
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GG

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Re: Glyn Guest's "Emily May"
« Reply #1 on: November 14, 2009, 10:59:19 am »

As the designer of this model I will attempt to answer the questions raised but not before establishing a few facts.
1) You say that the models was increased in size by 20%, does this mean that all the dimensions were increased by the same factor or just the length?
2) Did you build your model using the same design and materials as the published design?
3) You say "My model sits in the water well above the water line". Have you tried ballasting it down to the designed waterline?
4) What material have you used for the ballast, what is its shape and location?
Glynn Guest
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Peter Fitness

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Re: Glyn Guest's "Emily May"
« Reply #2 on: November 14, 2009, 11:07:14 am »

Ceres, some photos would also help Glynn answer your questions.

Peter.
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malcolmfrary

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Re: Glyn Guest's "Emily May"
« Reply #3 on: November 15, 2009, 10:29:14 am »

If the entire project was increased by 20%, then the result should weigh in at original +80%.
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CERES

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Re: Glyn Guest's "Emily May"
« Reply #4 on: November 16, 2009, 10:07:27 am »

 :-)Many thanks for your response and especially from GG.

Before I go any further I think you are right that a photo(s) would be in order. My problem is that I haven't a clue as to how you send a photo to accompany this article. Yet again I must request some guidance.
Ceres.
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dougal99

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Re: Glyn Guest's "Emily May"
« Reply #5 on: November 16, 2009, 10:21:13 am »

Ceres

Click on additional options which will reveal an attach option, browse your pictures and select the omne you want. select more attachments and repeat for more than one photo. If you need to resize your photo do a search on resize as the topic has been covered many times on Mayhem.

HTH

Doug
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GG

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Re: Glyn Guest's "Emily May"
« Reply #7 on: November 16, 2009, 05:14:51 pm »

Ceres,
        Whilst you figure out how to post photographs perhaps you can answer my questions, which really do not need photographs anyway.
GLynnG
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CERES

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Re: Glyn Guest's "Emily May"
« Reply #8 on: November 16, 2009, 09:07:53 pm »

GG,
Thanks for latest message. I will not bother with a photo since you know what model I am on about.
I took the plan from the MB and had it icreased by 20% which my calculation makes an overall length of 3ft x 5,25" on the beam and a tazz over 5" on hull height.

The weights used, a mixure of lead & steel blocks(small) brought the vessel down to the waterline according to my markings.
Ships superstructure and briage etc were all proportionate to the new size. The exception for me was that I fitted a small Radar scanner(Action)into the bridge housing running on a single AA battery.

Total weight used and distributed is as follows:-
                      Stern section with rudder system & servo additional weight......0.975kg
                      Centre hold with battery and action electronics plus weights.....1.200kg
                      Bow section including Thruster plus weights............................2.700kg
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The long Build

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Re: Glyn Guest's "Emily May"
« Reply #9 on: November 16, 2009, 09:54:12 pm »

Still post Pictures , GG may know what the model looks like but I am sure plenty do not.
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GG

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Re: Glyn Guest's "Emily May"
« Reply #10 on: November 17, 2009, 10:34:40 am »

OK Ceres, I think I can see the problem.
The original model (which works perfectly well and and displays the sedate stable sailing characteristics expected of a merchant vessel) weighed in at 3.6 kg (8 lb).  Enlarging the plans by 20% would give you a model now weighing at about 6.3 kg (14 lb) if ballasted to float at the original waterline.
I assume that the weights quoted by you are the internal items and do not add up to the models total weight?
I note that you say that the ballast "brought the vessel down to the waterline according to my markings" which is presumably not that shown on the plan. Your first post also says "My model sits in the water well above the waterline ..."
Without more detailed information on the models construction, I'd guess that your model just needs ballasting down to the designed waterline.  This should increase the hulls "stiffness" and reduce the side area to be affected by wind.
GlynnGuest
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Re: Glyn Guest's "Emily May"
« Reply #11 on: November 17, 2009, 07:04:37 pm »

GG,
Thanks for the info. Look, I must apologise for some incorrect quotes made in my message.
First of all the boat sits with the waterline beneath the surface by approx 3/8".
Total weight of ballast is 4.875kgs.
Total gross weight is......6.500kgs

I am trying to enclose a photo of my model but without masts and in its cradle. I hope it comes out Ok.
One suggestion from one of our members is to make up a keel of lead flashing to the weight already in but make is 20mm wide in folded sections and fix to the bottom.
Many thanks for your assistance.
Ceres.
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ZZ56

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Re: Glyn Guest's "Emily May"
« Reply #12 on: November 17, 2009, 10:20:36 pm »

What a nice looking boat!  I don't see how it could be tippy with that much hull underwater.  What kind of a wind are you sailing in and how much does she roll?
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CERES

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Re: Glyn Guest's "Emily May"
« Reply #13 on: November 18, 2009, 10:05:21 am »

 :-)ZZ56,
Many thanks for your compliment.  On a straight course and a steady speed she looks pretty good, its when I command a Sharp turn that she rolls, needless to say no ballast moves during the turns as they are fixed down with "Copydex" carpet glue.

Our sailing area which is situated next to the Aire & Calder canal in Goole can get pretty windy. A guess as to the pitch, I would say approx 20 - 35 degrees from the vertical.
Ceres.
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GG

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Re: Glyn Guest's "Emily May"
« Reply #14 on: November 18, 2009, 11:46:09 am »

OK Ceres,
           In your last post you say that "its when I command a Sharp turn that she rolls".   Well if you suddenly apply full rudder (30 degrees or more) to any displacement model traveling at speed then you ought to expect some roll, or heel if you prefer this term.
I see nothing wrong with this characteristic but then my preference is for powerful rudder and throttle controls to get me out of trouble but normally operated with restraint for more realistic appearance.
You still have to describe the models construction in particular the materials used.  The reason I ask is that over the years I have encountered some horrendously "over built" models.  One example was a modeller who made the superstructure out of solid mahogany, a beautiful wood but almost as dense as the modeller who used it for this application.  There have also been funnels made from thick walled steel tubing, which is even denser, material and modeller wise!  I'm sure that you do not fall into this category.
Likewise, weighty internal items need to be as low as possible inside the hull.  I well remember watching a tug, normally the most safe of subjects to model, which sailed  around in a most unstable fashion, even gentle turns had the deck edges awash.  On removing the tugs superstructure the large sealed lead/acid battery was seen to have been mounted "upright" rather than laid flat on one side.  I guess someone had told this modeller that lead/acid batteries can spill acid and so must be mounted upright?
GlynnG
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ZZ56

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Re: Glyn Guest's "Emily May"
« Reply #15 on: November 18, 2009, 11:05:39 pm »

Real vessels do roll when sharp course changes occur, and in crosswinds.   

What you might want to do is put the boat in a tank indoors, away from any wind, and tip it a measured amount and see how it responds.  If the boat rolls violently but soon stabilizes, most weight is low in the hull.  If the rolling is more gentle but prolonged, then the metacentric height is higher up in the hull.

Either way, it sounds like your boat is stable and the conditions are causing excessive rolling.
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CERES

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Re: Glyn Guest's "Emily May"
« Reply #16 on: November 19, 2009, 10:10:29 am »

GG,In reply to your latest message I have constructed the model as per the materials quoted in the MB.
The superstructure and hold are made from plasticard at 1.6mm thick. Windows have been cut out not painted. The masts are 50/50 brass & plastic tube. Crane houses Balsa & gantries plastic.
The only "weights" up top are 6 magnets 3/4" x 3/16" one for each crane and 4 to hold Bridge house down as this includes the small radar motor.
I use on one battery a 7.2V with 2200mAh.
Ordinary card has been used to form the bulwark and prow area this being 1.3mm.
Motor is as recommended.
I understand what is being said so I shall be conducting different weight ratios and perhaps by re-siting the radar motor further down the vessel.
I will keep you posted if I may.
Regards to you all
Ceres.
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