Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Yachts and Sail => Topic started by: JayDee on March 13, 2011, 07:44:41 pm
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Hello,
Finally made it to the Lake today after the major refit to my J Class, Endeavour.
New Cabins, fully planked Deck, new sails and a scale paint job too !.
The weather was very kind, light breezes with a few gusts, but sunny and quite warm.
Rigged up and lugged the boat to the water, weighs 40 lbs now, and away she went.
Almost sailed hands off, just a touch of rudder trim and that was it !!.
Had a real good afternoon of sailing, a good two hours.
Boat was bone dry inside when back on its stand and I was smiling a LOT !.
Been a whole lot of hard work, but this sail made it all worth it.
John.
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:-)) :-)) :-)) :-)) :-)) :-)) :-)) :-))
Very very nice John, more photos please.
Nige
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Hello Nige,
Thanks for your comments, these are all I have at the moment, will take more photos ASAP !!.
John.
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John,
She looks beautiful, thanks for sharing
Wicksteed?
andrew
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Hello Andrew,
Oh I do hope so, we have no trip to Germany this year, so God willing, I will be there.
The J Class will sail there OK, having a shorter Keel than the Schooner.
Nice to hear from you, what have you been doing ??.
John. :-))
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absolutely stunning John what woods did you use on the deck planking?
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Hello,
I have a friend who is "in the know" with woods, so I took his advice to choose a wood which would look like Pine, which was used on the real Endeavour.
The grain on Pine was too big and didn't look scale on the deck, the wood he chose was Ash, in a Veneer 0.6 mm thick.
The Deck planks are 4.5 mm wide and were Varnished with Yacht Varnish, the margin planks and the King planks are Obechi wood.
I am an Engineer, and for me, working with wood is a punishment!, it splits, breaks and is not at all like working with metal!!.
After a very long time and many, many planks I finally got the job done - - - and I like it !!.
John. :-)
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Lovely Job Jaydee
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great finish , i hope i get the same on my project when i no what hull it is......Larry
(http://s3.postimage.org/235rde4uc/P1030365.jpg) (http://postimage.org/image/235rde4uc/)
(http://s3.postimage.org/2367wrls4/P1030363.jpg) (http://postimage.org/image/2367wrls4/)
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Larry , what is the little boat ? It looks like a suitable deck for a Springer.
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Hello,
During the test sail on Sunday, the Quad sail - - the outer Jib, was showing signs of creasing during the gusty parts of the sailing.
Today I have been moving the sheeting points on the Quad, to see if this creasing could be rectified.
On the real boat the sheets for the Quad were taken well aft, two sheets either side of the boat,
Doing this on a model would mean that the Quad sail would not be able to Tack, the Crew moves the sheets to move the sail.
Models have NO Crew !!.
Having the sail set on the wrong side during a Tack would not look right , so more work needs to be done.
John.
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Topic split: NZ TROW ALMA - http://www.modelboatmayhem.co.uk/forum/index.php?topic=29340.0
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Good thinking Martin, I see a rush ( or is that a rash) of these developing. :}
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Hello,
Had quite a struggle getting the Quad sail to set correctly.
The Quad sail is not a triangle like the Jib, the Quad is shaped like this " /_____\ " with the tops joined.
So the sheeting on the top and bottom has to be just right for the sail to set correctly.
I have a alloy tube, an old Mast, which I fastened to a 3 foot piece of wood, to make a very large "L", which I then used as the front of a "Dummy boat", and set the Quad and the Jib on it.
I could then stand in the wind with the sails set as they were on the boat, and adjust the sails very easily, no weighty boat to turn from side to side - - very nice !!.
A couple of my neighbours saw me doing this!,- - thought I was cracking up !.
Well worth it, walking the frame into the wind gave me the effect of a gust of wind, going the other way gave me calm conditions.
A DIY Wind Tunnel !!!.
John.
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Hello,
Removed the Bowsies which were setting the sails during the test sailings and fitted the two winches.
The Quad and the Jib are controlled by a Hitec lever arm winch, a 815 BB.
The main is controlled by a RMG 380EH winch.
The Rudder servo is a 1/4 scale Futaba one.
Power is supplied by a 6 volt 4Ah Nicad.
The radio hatch seemed rather big when building the boat, but it very quickly filled up.
All the Gear is on the large side !!.
Waitng for some nice weather to do some more testing.
John.
(http://s3.postimage.org/agbx1xg/J_Class_1.jpg) (http://postimage.org/image/agbx1xg/)
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John, there's this approach (http://www.rcgroups.com/forums/showthread.php?t=769105) to controlling a loose-footed outer jib - it allows tacking and decent sail set on everything but a run. Any use?
Andy
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Hello Andy,
Many thanks for the suggestion, I already had that thread saved, good idea!.
There are other variations on that theme, not tried any YET !!.
Sailed the boat today with the two winches working, very, very nice to sail.
Got a few points to tidy up, but nothing serious, it all worked very well.
In fact it was good enough to leave well alone !!.
I might just enjoy sailing for a while, after all the time and effort.
BUT !!.
John. :-)
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HI JAYDEE, model looks good you no your stuff, do you think my sad looking hull is a J CLASS ?.....
ready to start refurbish but still looking for help on rig and boat plan........LARRY W .....
(http://s2.postimage.org/1hwb7chus/P1030365.jpg) (http://postimage.org/image/1hwb7chus/)
(http://s1.postimage.org/x1uqqqf8/DSC8855.jpg) (http://postimage.org/image/x1uqqqf8/)
(http://s1.postimage.org/x230fgw4/DSC8856.jpg) (http://postimage.org/image/x230fgw4/)
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Hello,
After yet another "test" sail at the Lake, Endeavour was sitting quietly on the stand
when she was inspected by some Club Members !!.
Big sigh of relief from me - - - when they finished they were smiling !.
John.
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Hello,
First picture of the boat with the trim lines and the waterlines on.
The waterlines were rather hard to get right, because of the rather long overhangs of the hull.
So, Endeavour now looks a lot more like the real one !.
John. :-))
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Hello,
Sailing today, minding my own business, when two Ducks landed right beside the boat.
Gave me quite a fright !!.
John.
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John it isnt so easy on a model boat the set the jib and Yankee sails is it is on a real yacht as you dont have any cars to alter to set the
sheets for different points of sail, but you seem to have got it about spot on as she looks great on the water.
A really nice looking boat.
Geoff
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Hello Geoff
The biggest time saving gadget was the frame I made to hold the sails into the wind, as mentioned in Post#13.
Doing that saved a lot of time setting and altering the sails.
No waiting for calm or gusty conditions!, full set of weather as and when it was required!.
Best bit of kit I have made for a long time.
John. :-))
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Hello,
Endeavour, sailing on the Runcorn Model Boats lake.
More to follow.
John.
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Hello,
Been out sailing Endeavour in our very nice weather.
Still sailing with the "Test Sails" will make some proper ones over the Winter months.
John. :-))
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Hi Folks
I am a total newbie to RC Yachts and totally delighted with my first yacht being the Laser.
I have just spent some time reading these excellent theads to your opening topic and WOW what a Yacht yours is!
Even by my very inexperienced standards yours is a vessel to be very proud of.
Thank you for sharing the excellent photos.
Cheers
Craig :-)) :-))
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Hello,
Craig, Thank you for your very kind words.
John. :-)
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JayDee, if you had used a Chevy V8, you wouldnt need all these pulleys and things !!.
The Stig.
(http://s13.postimage.org/isahnx1lf/The_Stig.jpg) (http://postimage.org/image/isahnx1lf/)
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In a couple of weeks time we are going to get ACTUAL J Class Yachts down in Falmouth,racing in Falmouth Bay.I am not a yachtie person,but boy am I looking forward to seeing these maginificent boats in full sail.
Mick F
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Hello Mick,
YES, me too, I am looking forward to seeing them!.
John. :-))
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Hello,
The J Class sailing Event on the Solent, are there any Forum members who know the area well enough
to recommend a Vantage Point for the best view of the yachts when they are sailing ?.
John. :-)
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Mr Mr can i have a go
Lush boat :embarrassed:
Dan
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Hello Dan,
Living in Portsmouth ,you MUST know of a good viewing point along the Solent.
An ideal spot would be on higher ground, with a short shore to the water.
The folk who are running the event, don't give details of the course the boats will be sailing,
other than East, West, or Central Solent !!.
So, where would the best place to be to watch the Races ?.
John. {:-{
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Castle fields is the best place to sit along the southsea shoreline, its high up and has benchs along it :-))
Dan
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Hello Dan,
The Course seems to be over towards Ryde Pier, your spot maybe too far away.
Any other places more to the North, up the Solent river?.
John.
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can you post a piccy of the course john ? must have been a j class i saw leaving gosport on monday
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Hello,
There has been no course published only viewing points.
Its almost as if they were keeping things to themselves!.
One of the links is this - - -
http://www.jclasssolentregatta.com/press.html
John.
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Courses are usually decided on the day taking into account the wind direction so as to give legs on different points of sailing.
No secrecy, just something that cannot be planned too far ahead.
Ned
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Hello,
Couple of photos of Endeavour on Heath Lake, Runcorn.
John.
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Jay dee.,had the pleasure of meeting you and a good talk today at Haydock ,nice to see the yatch in person ,so to speak ,and to meet you ,well thankyou ,regards Dave .
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Hello,
A photo taken at the Haydock event, the boat is on its Stand, too tall to go onto a table!!.
Others taken at the Runcorn Clubs Lake.
John.
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Great photos John.
... nice to see it with out the optional pole up the back stay!!! :kiss:
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Lovely to see JD
Just a thought, would a tack tackle or downhaul on the gooseneck
take the creases out of the main when beating to windward?
Ned
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Lovely to see JD
Just a thought, would a tack tackle or downhaul on the gooseneck
take the creases out of the main when beating to windward?
Ned
Beautiful boat, thanks for sharing :-)
Could it be that the mainsail creases are being caused by the jib /staysail backwinding the main?
Do the creases move/ripple or are they in the same position all the time? If so, perhaps some alteration of the slot may help...
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Hello,
The sails were meant to be "Test sails", but lazy beggar me has not made any new ones!.
The sails are made of Mylar plastic sheet, which is rather stiff, they are ok on some tacks but not on others.
The creases do bug me, but the boat sails so well I don't bother too much about them.
The Proper sails will be made of Silk, which I can buy at a good price.
Eventually, I will get around to making them !!!.
John. :-)) :-)) :-))
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Hello,
This is the latest photo of Endeavour, sailing with the large Jib, as per the real boat.
Much better performance than the other setup, probably because this is easier to set up!!.
Would like to "hide" the Jib Boom inside the sail, the real boat did not have a Boom, but without one on the model, the sail was awful!.
John. :-))
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Hello,
Just found this video of J Class boats sailing.
View full screen, with the sound on.
The best one I have ever seen !!.
http://www.jclassyachts.com/videos (http://www.jclassyachts.com/videos)
John. :-))
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Hello,
This is a video of a full sized J Class boat being built.
Amazing construction and handling !.
http://www.claasenshipyards.com/news/141/j_class_yacht_atlantis_j_7.html (http://www.claasenshipyards.com/news/141/j_class_yacht_atlantis_j_7.html)
John. :-))
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Hello,
Will be sailing my J Class Endeavour this weekend at the Ellesmere Port Show.
Everything checked and ready, just hope the weather is kind !!.
John :-))
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Hi jaydee I agree a jib boom does not look so good. I now use a piano wire of appropriate diameter slid into the lower seam of the sail. You will have to experiment with the bendiness of the piano wire to suit the curve of the sail with the wind on it.
Anyway worked for me.
good luck,
Roy
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Hello Roy,
That is a good idea !.
Will have to give it a try.
Thanks for the tip !.
John
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Hello,
Did a lot of sailing at the Ellesmere Port event, here is Endeavour "In Dock", during a break !.
John.
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Hi Roy and Jaydee, what about using piano wire to make a wishbone instead of a jib-boom, similar to the rig between the masts on a schooner? It would be less noticeable than a jib-boom and allow the foot of the heads'le to take a nice curve.
Jerry.
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Like these.
Jerry.
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Hello Jerry,
Both of the Jibs shown have a very stiff plastic rod fitted into the bottoms of the sails.
Almost "hidden",they are to stop the sail from curling in the wind.
The problem arises from the sheeting points being in the centre of the hull, instead of the real life positions.
They sould be sheeted from the very edge of the deck, pulling the sails down and keeping them nearly flat.
Big problem - - - there is no Crew!, the Crew would move the sheeting points when the boat tacked.
No way to do this with Rc !! - - - OR, keeping things looking Scale.
John.
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Hello,
Just got an invite to the "J Class day", hosted by the Nottingham Model Boat Club, at Colwick Country Park, Mile End Road, Nottingham. NG4 2DW on the 27th of July 2014.
I went to the event last year, a really good day out!, very good lake, very nice people - - and lots of Sailing !!.
Looking forward to meeting up with all the folk I met last time and seeing their fabulous boats !.
Will be taking my J Class, Endeavour and am hoping to leave some grooves in the water.
John. :-)) :-)) :-))
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Hope to see you there John.
Nige
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Hello,
Got a busy weekend coming up, next Saturday I will be at the Daresbury Steam Fair, near Warrington.
As a member of the Runcorn Boat Club I will be showing the J Class and my One Metre boat - - display only.
We will have a small Pool for the smaller boats , the children also get to sail some special boats - - they love it.
Then, on Sunday I will be at the Kirklees Club Open Day - - - SAILING !!!!.
Lovely Lake and People, always enjoy being there.
Looking forward to both Events, hope the weather holds up, got my waterproofs if not !.
John. :-) :-) :-)
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JayDee, if the foot of the jib is rising, how about installing a downhaul, similar to the installation on a mainsail. The downhaul would run from the foot of the jibstay out to your plastic "boom". This jib downhaul would not have the down-force power of a mainsail downhaul due to the acute angle between the jibstay and white plastic boom (vs the almost a right angle between mast&boom). But, it should reduce lifting of the boom.
For a more elaborate fix, you could run the downhaul to a semi-circular track, rather than the foot of the jibstay. This would give a better angle for the downhaul, at the expense of possibly needing fiddly adjustment and tuning.
Your ships are beautiful, so nice to see the photos :-)
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Hello Brooks,
I have moved the Jib pivot aft about 4 inches, it used to be at the fore end of the Jib.
This gives enough down force to give a much better set to the sail.
The sail now is much better than before.
Thank you for your very kind comments.
John.
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Nice fix, simple and effective :-)
If you were to put a crane under the tack of the jib (i.e. under the boom tip extending fore of the new jibstay attachment), you'd eliminate any rise at all. The crane would have to be curved to match the arc of the boom, of course. I'd make the crane a little lower than the boom tip, just to be sure not to introduce drag when the boom needs to switch sides in a tack.
Also, if you are still having problems with wrinkles in your mainsail - The photos I saw suggest that the sail might benefit from a Cunningham. I don't know if mylar would work with a Cunningham, though. But when you make your silk sails, adding a grommet an inch or two above the tack would allow you to add a Cunningham if you wanted.
http://en.wikipedia.org/wiki/Cunningham_%28sailing%29
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Hello Brooks,
There are many other modifications that could be done to the boat to improve its performance, but, they would not be to Scale !.
My boat already has a non Scale Keel and Rudder, I wish to keep things as they are.
The Keel and Rudder are not seen while sailing, altering the Rig is in full view all the time.
The boats performance is very good with things as they are now, to improve it would need major changes.
For me, "Scale" wins every time !!!.
John. :-)) :-)) :-))
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Hello,
Got another trip out, on Sunday 27th this month, sailing at the J Class Day at Nottingham !!.
Have given the boat a bit of spit and polish! - - bound to bash her into something and scratch things !.
The weather seems to have settled down, hope it keeps fine for the Event.
John. :-)
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Hello,
The weather at Nottingham J Class sailing Day was very, very good.
So was the Lake, the Wind and best of all, the Company !!
Loads of laughing and chatting, good food too.
A real good day out.
Sailed my J Class in the company of lots of the Nottingham ones, they are fantastic boats, able to cope with large changes of weather with ease.
Their build quality is very good, Laser cut parts, and the Glass fibre Hulls have to be seen to be believed.
They make my Hull look decidedly dodgy !!!!.
Thanks to all who attended - - - Roll on next Year !!
John :-)) :-)) :-)) :-))
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@JayDee:
That sounds like a great day out, would love to see some photos or video if there is any available. We don't see this style of boat in my part of the world...
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Hello mrpenguin,
I had "Finger Trouble" with my camera !!, but here are a few photos.
John.
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Thanks JayDee!
Having them next to the car gives an indication jus how big these boats are! Surely you did not squeeze all three in that car????
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Hello mrpenguin,
Yes, all three boats, more Hulls and lots and lots of other things were all in the owners car.
My own boat at 6 feet long fits easily into an Estate car, some times with camping gear, tent etc
.
If, it has to fit in - - it WILL !!!.
John, :-)
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I am so pleased it isn't just me with a carload of boats - here with two A Class plus a dragon Force (and the dinghy, markers, outboard, etc)
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Pretty good for a Mini %% %%
Ned
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Ned that isn't a Mini, it's a Subaru Forester... It is pretty squeezy if I were to have a passenger! Passenger has an A Class bow in each ear ;-)
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Hi Mr. Penguin Forrester is a nice car, I had a breakdown with my car when visiting a friend and car was in garage etc for repair. (A faulty replacement exhaust baffles had collapsed) My friend had a Forrester and lent it to me for 3 days to get home etc. It convinced me what sort of car I wanted next, and a few months later I bought a Honda CRV, Had it for the last 13 years! Great car, takes my yachts etc.
regards Roy
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Another cheer for Subaru! :-)
For years in the 1970's, they were the best-selling Japanese brand in the New England states. If your typical winter weather consists of 3' of snow, changing to 6 hours of rain, followed by 6 hours of freezing rain, which transitions into a 72-hour deep-freeze with howling northerlies, then you can't go wrong!
Tom
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Hello,
The Bridlington Open Weekend is almost upon us!, I have just finished checking the J Class, it will be a "testing" time at the event - - done some mods to the Keel.
Because of the bad weather the boat has not been sailed since the mods, so, fingers crossed that all will be OK !.
Been having problems with the boat rounding up into the wind when hit by a gust, I have added more area to the rear of the keel to help with the balance.
To keep the Scale appearance the mast could not be moved, so the keel had to be altered!.
The keel is non scale anyway, so altering it was the easiest thing to do.
Just need some nice sunny, windy weather to test her.
John, :-)) :-)) :-))
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Can you slack the jibsheet to reduce weather helm in a gust?
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hello Brooks,
Have tried every setting possible with the sails.
Time for alterations !!.
John, :-)
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Can you slack the jibsheet to reduce weather helm in a gust?
Whoops, I wrote this BACKWARDS! To reduce weather helm, one needs to slack the Mainsheet. Or, tighten the jibsheet, or do both. Sorry.
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Sloops can be harder to manage than squareriggers when the vessel turns into the wind due to excessive heel: The long boom of the mainsail will hit the water, limiting the skippers ability to spill wind from the mainsail. I see this all the time with my sandbagger sloop. But squaresails can be squared in, spilling wind, even if the lower yards are in the water. I see this (with barque Pamir and brig-rigged Aldebaran) whenever I carry too much sail for the wind/gusts, and have to contend with a knockdown or near knockdown. The heel of a moving vessel automatically turns the bow into the wind due to the asymmetric thrust of the bow wave.
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When designing a hull/keel to match the scale sails and scale mast locations, I try to align the Dynamic Center of Effort of the sails (dCE) and the Dynamic Center of Lateral Resistance of the hull+keel+rudder (dCLR). When the centers are aligned, the rudder is most effective.
Many builders don't appreciate that the static CE/CLR is not in the same place as the dynamic CE/CLR. When the ship is moving, the dynamic centers rule, not the static centers. While the static values are at the geometric centers, the dynamic values are shifted forward to the 1/4 chord point. Example: static value for a 4 ft hull CLR is at the center, ie 2 ft aft of the bow. But the dynamic CLR is only 1 foot aft of the bow. This is per aviation practice; since sails and hulls and keels operate as lifting bodies, anything you know about airplanes will help you fix boat balance/maneuverability problems.
The common method used by modelers to find the CLR is to push the hull sideways. Where their finger is placed to get the boat to move w/out turning is the Static CLR. Now, to find the dynamic CLR, measure from the bow to your finger, and cut that distance in half. This will give you the 1/4 chord point, a good starting place for your endeavour to get the CE lined up with the dCLR. dCLR can be anywhere from 1/4 to 1/3 chord point, per aviation experience. Its never at the 1/2 chord point, though, which I've seen gets builders in trouble if they don't know that.
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The dynamic CE moves forward during vessel movement, just like the dynamic CLR. I do my figuring of sail dCE on paper: find the geometric center of the triangle (jibs and fore&aft mainsails). Then, estimate the 1/4 chord point by splitting the distance from the geo center to the mast. Then measure the distance of the sail's dCE from the bow. You will want to know the relationship between the dCLR and the dCE, so choose a common datum; I use the bow as the datum for both CE's and CLR's.
Since most vessels have more than one sail, find the dCE for each sail. Then, find the summation dCE for all sails by weighting each sails' dCE by the sail's area. I do the math just like calculating a center of gravity for a plane:
(dCE1 X sailarea1 + dCE2 X sailarea2 +.....)/(sailarea1 + sailarea2 +...)=Summation dCE
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The same equation can be used to find the summation dCLR for a hull plus finkeel plus rudder. For my boats, the rudder is always way oversized vs scale size, so I include the rudder in my calculations.
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For squareriggers, which can strike sails (at least mine are designed to do that), I may calculate several dCE's to see how the vessel balance will change as I adjust for wind speed changes. These calculations are easiest with a spreadsheet.
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"Drag" is the term used for hulls which are deeper aft than forward. Clipper ship hulls generally had no drag, but Schooner and Topsail schooner hulls usually did. A hull with drag starts out with the static CLR farther aft than the same hull w/o drag. Thus, the dynamic CLR will be further aft (compared to a dragless hull) when the vessel is moving. I suspect nautical architects of the 1800's realized their ships did not balance like they expected, so added hull area aft to compensate. Many of the 1800's "rules of thumb" of ship design I've read unconsciously adjust for the fact that hulls are generating lift, thus are ruled by then-unknown aeronautical physics.
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Hello Brookes,
Yes, I spotted your "whoops" - easily done !.
You are very used to applying formulas to designs for full sized boats.
I have quite a few books on the subjects.
However, do all these rules and ratings still apply to a model boat ?.
My boat is at 1/22 Scale, it has to sail in full sized Water, it has to sail in full sized Winds.
Neither of these elements can be Scaled.
Picture this scene, an nice sunny afternoon, a nice large lake, a nice breeze blowing - - around 10 miles per hour, a few other model boats moving about - - very nice conditions !.
Or are they?, my boat sees this as a wind blowing at Hurricane force, with huge waves, which they are, if scaled up 22 times !!.
There has never been a full sized yacht that could sail in such conditions - - or a Lifeboat !!.
I am trying to make my boat sail in conditions which are way beyond those which real boats sail in.
John, :-)
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My CE and CLR formulas are not a scale/non-scale process. The physics of balancing where the wind pushes (CE), and where the water resists (CLR) is scale invariant. I mentioned them because solving a maneuverability problem is hard if you base your fix on 1/2 chord balancing.
When it comes to scaling the rest of the boat: opinions vary, hoho. As you pointed out, a 10kt breeze is ideal for a real ship, but strong medicine for a model :-)
I always make my squareriggers so that I can easily reduce sail area. Jimmy James figured out how to use lazy jacks to reduce fore&aft sail area (ie furl) on his vessels, eg. his brigantine Freebooter. I've admired his work, but never implemented his ideas. Mainly, that's because my sail cloth of choice is Tyvek, which does not furl.
Its easiest for me to just remove a squaresail and it's yard entirely from the mast (rather than furl them per real practice). Or remove a jib, or other fore&aft sail. My schooners and sloops (no furling, no sail removal method) are definitely wind-limited in a way that my squareriggers are not. I've sailed my Pamir in 22 gust to 27mph winds, which requires reducing sail to what a real ship would set for a real gale. Still, it's challenging to maneuver in such "scale gale" conditions.
When a model is getting knocked down, or heeling so much the bow wave=>turn to windward is uncontrollable with rudder, I always recommend that the modeler figure out a way to reduce his sail area. This works for the real ships, and for models too.
Increasing heeling resistance by deepening the keel (placing the external ballast lower) also works: but you risk running aground farther out than you are used to, or snagging seaweed that normally you could sail over with no problem. The shrouds may have to be beefed up, also. I have formulas to deal with keel length and shroud strength if you are interested.
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@Brooks22:
Thanks for the info on dynamic Centre of Effort (CE).....
I am comfortable with locating static CE, but just struggling a bit with dynamic Centre of Effort (dCE)..
For discussion, can I propose one simple sail, aft of a vertical mast, attached to a horizontal boom (thus it is a right angle triangle). This mythical sail is 10 units up the luff and 6 units across the foot
As I understand it Static CE (geometric centre) of this sail would be 5 units up from the bottom and 3 units from the mast.
From what you have posted I gather the dCE would be at 1/4 chord; thus it should be 5 units up from the bottom and 1.5 units from the mast.... Have I got it right????
I would have thought that with heel (say 45 degrees) that the dCE would move aft of the static CE, not forward from it.....? I think I understand the bow wave turning the boat into the wind when heeled....
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Yes, you got it right wrt dCE on your test sailboat. :-)
I don't know how dCE moves with heel. It does not move on an airplane with bank, so I just thought that heel would not affect it. Unless you have some info I don't (perfectly plausible, I don't know everything), may I make the following suggestion: Heeling increases the strength of the bow wave asymmetry, which increases turn to windward. This would mimic a move of the dCE aft....so, maybe movement of the dCE is not needed to explain what we see happening.
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Hello,
Did a lot of sailing over the weekend with the modified keel on Endeavour.
The boat has been tranformed !, it handled a full Gale with ease!!.
One Metre boats had their storm rig on, it was so windy.
The boat still heels and turns slowly into the higher speed winds, but in a very controlled fashion, gaining a lot of speed while doing it, very handy for racing !!.
This was happening with the rudder at neutral setting.
With the rudder correcting, a straight course could be followed.
I am now one very happy chappy !!!.
John, :-) :-) :-)
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@Jaydee:
Any chance you could post a pic of the alteration to the keel please?
(Looked back through the thread and in all the photos I found the keel is hidden by water or stand :-) )
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Hello mrpenquin,
Not got a photo of the "latest version" of the keel.
Here is the original, and the first modification, with the latest one shaded in as close as possible!.
Everything has been packed away.
John.
***typo corrected at posters request***
***TT***
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Thanks John, clearly a big increase in fin area and you have move the CLR back quite a bit. Good job!!!!
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Hello,
Been sailing Endeavour at our Club pond at Runcorn.
Last Wednesday and today, both days with hardly any wind !!.
Did some testing of the camera rig on the rear of the boat - - a GoPro camera.
The camera is on a device which keeps the horizon level when the boat heels in the wind.
BUT, there was not very much wind to test it !.
No pictures of the rig, not available commercially - - home made!, but works very well.
John. :-))
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John
Your yacht on the lake today.
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Oh Man, is that Beautiful, or what. We may not be able to live in the 1930's, but with models like this, we can at least experience the elegance and beauty of the era. Thanks JayDee!
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The modern ones aren't too shoddy, either!
(http://cdn.sailingscuttlebutt.com/wp-content/uploads/2014/07/JCLASS.jpg)
Andy
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Hello,
Got the J Class Endeavour out of storage, big cleanup and some repairs, ready for the first sail of the season on Sunday.
Will be sailing at the Heath lake, Runcorn, which has had a major rebuild by the Council.
Much deeper than before, all new walkways, aeration devices in the water, childrens play area and a new Cafe.
Forecast is for good winds, so looking forward to it !!!.
John. :-))
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Hi Jaydee, Have you thought of having 2 fore sails as per the 1934 version?
A quadrileteral looks really good on Endeavour it will have to be cut back a bit so that it can tack across the jib though. I see you have already cut the main sail back so that it does not overhang the stern,
Nice to see J's sailing.
best regards Roy
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Hello Roy,
See earlier pictures in these posts.
John.
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Hi JayDee, here is my Endeavour at exhibition in 2004 / 5,
My one is a little smaller at 1 metre loa, but you can see the overlap of the Quadrilateral, it is about 2 -3 cms. It does seem to tack OK and cross the jib without much problem. The sails are drafting film and you can see a join on the main sail.
Can't find any sailing pictures on my laptop at the moment.
I did not expect to carry the quad in any sort of wind and it is easily removeable and a forestay put in its' place. The extra keel was balanced with the sails for neutral running without the quad. So sailing with the quad required some helm on the rudder, but there is so much sail area that it is not a problem.
The full size Endeavour after restoration is 300mms lower in the water and has a big propeller, such a shame.
regards Roy
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Hello,
This is probably not the correct place to post this, but I have got my Website back on line !!!!!.
Still needs a lot of work, but I have lots of goodies to put onto it.
Be gentle and have a look!.
www.john-dowd.co.uk
John.