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Old Dec 16, 2012, 04:43 PM
RB
Joined Nov 2012
118 Posts
Planked Hull etc

Kevin,
In my- your dreams - and with mini lags. Sorry a mis-type.

The weight of your boat gives me some encouragement; that's 5.8% under. As much as Al's Soling is overweight . When I mentioned heavy Solings I mean 3 -4 oz or so.

I have an 815 BB so I guess I'll use it. At 6 volts I think it has more oomph than the 7950 at 6 v - it needs 7.4 v for max performance.

The shroud rack issue still puzzles me. The mere existence of the rack of that length suggests the mast is moved considerably or raked. In the Victorias we rake the mast for and aft about 2 " but don't necessarily move the shroud attachment. In Solings you move the shroud position with the mast. Perhaps a study of EC 12's would be more informative.

Thanks again,
Richard
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Old Dec 16, 2012, 05:55 PM
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poltergeist's Avatar
Pomona, CA
Joined Apr 2007
706 Posts
I assume that maybe the mast step needs to be moved forward as you step down to the B or C rigs. Even so, I don't think it's imperitive that the shrouds move forward with the mast step. In fact as the lower shrouds move aft in relation to the step, they allow more control over mast bend, which should come more into play as the windspeed increases. At least that's my theory, as I've yet to sail my boat in all that much wind, so haven't seen the need for the B or C rig. Of course the drawback is that the shroud tensions need to be adjusted if they don't "follow" the mast step.

The Hitec 7950 has more power than the 815 even at 6 volts. Not sure it's a big deal as it seems that many C-J's (at least in the USA) are using the 815 with no issues. I like the fact that the 7950's speed and rotation and resolution can be programmed, but I imagine a high end transmitter can accomplish the same. If ya got it use it, right?

Kevin
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Old Dec 16, 2012, 07:53 PM
Silly Old Fart
CaptainBit's Avatar
New Zealand, Wellington, Masterton
Joined Mar 2006
228 Posts
15. I noticed CaptBit's boat has no shroud racks can you comment, please Capt ?

Hey Richard. IMHO shroud racks are not necessary and their weight can be eliminated. "Get it right and have it welded"
My A rig mast is made from arrow shafts and the smaller rigs have no spreaders fitted. Shrouds are terminated around 300mm/12 in below the head of the main on the A rig.
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Old Dec 16, 2012, 09:32 PM
RB
Joined Nov 2012
118 Posts
Shroud Racks etc

Thanks Cap,
To continue this.... do you use a B rig and if so then shrouds are at the same location - (?) Where do you step the mast ? Do you move it for and aft or rake it ?
Do you bend the mast - depends on sail cut, wind speed, but ...??

Sorry if I sound like a kid in a candy store; but what can I say ...

Richard
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Old Dec 16, 2012, 11:53 PM
Silly Old Fart
CaptainBit's Avatar
New Zealand, Wellington, Masterton
Joined Mar 2006
228 Posts
Quote:
Originally Posted by R Baker View Post
Thanks Cap,
To continue this.... do you use a B rig and if so then shrouds are at the same location - (?) Where do you step the mast ? Do you move it for and aft or rake it ?
Do you bend the mast - depends on sail cut, wind speed, but ...??
Sorry if I sound like a kid in a candy store; but what can I say ...
Richard
Gidday Richard.
I use as my next change down what was the old B rig but is in fact now a C rig.
Reason is they (class governors) designated a new B rig with a 1330mm luff.
I feel that this is not a sufficient drop in area to bother with. However I have not been racing this class seriously for long enough to be certain.
My second rig is a luff of 1150mm. The current rule designates this as a C rig.
I do have one other which was the old C rig which has now been retired from the rule. This has a 920mm luff. I designate as my D rig.
The shroud attachment on my C rig are at 400mm below the head of the mainsail and as stated previously there are no spreaders fitted.
The philosophy behind this design is that the top of the mast should be allowed to bend sideways in a gust and so free the leech of the main, spilling wind and so allowing the boat to carry on trucking instead of being knocked down and staggering. It seems to work well.
My mast is keel stepped inside a mast box and is currently at 525mm from the bow to the front edge of the mast and is raked back also. Shorter rigs use the same position and seem to work fine. My A rig mast is set straight with very little tension on the backstay. The arrowshaft material is very light and quite stiff but can be distorted with too much backstay tension. My A sails are by Peter Vincent and have a straight cut luff. The C rig will take a little more backstay which ensures a tight jib luff which is essential for good pointing ability. The sails are an old set of EC12 made from heavier material that I have cut down to size.
They will take a little bit of luff round.

Never worry about asking questions my friend.
That`s what this forum is all about.
There is so much accumulated knowledge amongst the readers here that is going untapped. Others may have totally different solutions or views. It is good that we can answer questions express our opinions and so use that experience to help keep the sport alive and expanding. Just remember there is nothing new. We have all learnt it from someone before us. Best wishes from the middle of Middle-Earth. Ian.
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Old Dec 22, 2012, 12:52 AM
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poltergeist's Avatar
Pomona, CA
Joined Apr 2007
706 Posts
Merry Christmas and Happy New Year!!!

Hope everyone out there has a GREAT Holiday!!!! Here's my cheapo, homemade Christmas card!
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Old Dec 22, 2012, 12:18 PM
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Ed Crowell's Avatar
Southern Calif
Joined Dec 2005
1,856 Posts
Great picture. Christmas in California.

Merry Christmas,
Ed
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Old Dec 22, 2012, 12:58 PM
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jimhurley's Avatar
Sequim, WA
Joined Jan 2004
182 Posts
Kevin,
Would you show us a picture of your gooseneck, I like your stay adjustment setup. Did you bend a loop into the end of the threaded rod to attach the stays? Could you give us some details of all of your rigging, it would be a big help to me and I'm sure to others that will be building CJ's in the future? How did you make the spreader ends, is that brass rod bent into a loop and inserted into a brass tube, and what diameter is the tube?
I seem to be full of questions this morning, the coffee must be working over time.
Thanks for the Christmas picture with the sun and the shadows I needed that. Here north west of Seattle, yesterday was the first day we've seen the sun in weeks.
Jim CJ #503
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Old Dec 22, 2012, 08:15 PM
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poltergeist's Avatar
Pomona, CA
Joined Apr 2007
706 Posts
Jim,

My gooseneck started as a square bar of aluminum that I "Flintstone" machined with a bench grinder, Dremel, and drill press. It bolts through the aft face of the mast into another aluminum threaded insert slid up inside the mast. The pivots are simple ball-links tapped into the top and bottom of my "piece". Hopefully the picture explains it better. My spreaders are 1/8" ID brass tube, which slides over a 1/8" OD stainless bar that's inserted through a hole drilled through the mast. One spreader is glued to the ss bar so when installed with tension on the shrouds nothing can fall out. The ends are simply brass cotter pins flattened and epoxied into the ends of the spreader tubes. Ed Crowell silver-soldered small tubes on the ends of his spreaders (I think) and his are MUCH nicer and cleaner than mine.

As far as my stay attachments, I just used "Great Planes" threaded couplers that are drilled and allow you to pass the stay wire through and crimp it Then a little shrink sleeve over to make it look prettier. There's a good pic of them here http://www3.omnimodels.com/cgi-bin/w...I=GPMQ3835&P=7

Hope the pictures help, I'll take more if you need them.

Kevin
Canterbury J #551
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Old Dec 30, 2012, 12:06 PM
RB
Joined Nov 2012
118 Posts
Rudder Linkage - Hull 563

Happy New Year All...
I'm having .... a of a time getting a smoothly operating servo to rudder linkage. Can those with well engineered installations provide some pics and dimensions. Dimensions that would be helpful are: vertical distance from the top of the deck to top of the servo; and distance between centers of the linkage points. I have tried using a ball joint connector at the rudder and an adjustable connector at the servo. Two ball connectors seem to work better but, I'm not happy about the loss of easy adjustment . As well the operation of the rudder arm causes some upward force that I am concerned could lift the rudder off the lower fitting at the bottom of the keel.
Any help would be appreciated. Thanks.
Richard
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Old Dec 30, 2012, 01:30 PM
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jimhurley's Avatar
Sequim, WA
Joined Jan 2004
182 Posts
Servo to Rudder setup.

Richard,
Check out my thread: http://www.rcgroups.com/forums/showt...1727959&page=3 to see what I did with the rudder linkage. There is no play and no binding that I can detect. I'm not to the sailing point yet, so I haven't tried it in the water. I can get more that 30 degrees of movement either side of center, the restriction on more travel is the rudder hitting the keel. Everything I've read on other boats, and that is not many, says 30 degrees is optimal. I have a Futaba 7C that I will use for the transmitter and it allows me to center the rudder. Saying that my setup is darn close without any transmitter adjustment. The easily disconnected ball joints make fine tuning easy. The servo is mounted so that the servo arm is in the same plain as the rudder arm when they are centered, judged by eye. There is too much variation in deck height between the two points to make an accurate measurement. My deck is curved bow to stern and port to starboard. After you find the pictures of the setup keep scrolling down to get the information on the linkage that I used.

Jim
CJ #503
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Old Dec 31, 2012, 03:18 PM
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Ed Crowell's Avatar
Southern Calif
Joined Dec 2005
1,856 Posts
Richard,

I laid a strait edge across the hatch opening (side to side) and measured from the top of the servo to the straight edge.

From the top of the servo it is 2 1/2 inches.
From the top of the servo arm it is 2 3/16 inches.

My rudder arm on the rudder shaft in level in the neutral position. Also note the shaft between the servo and the rudder arm is mounted on the under side of the rudder arm.

Ed
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Old Dec 31, 2012, 09:34 PM
RB
Joined Nov 2012
118 Posts
Rudder Servo Connection

Ed / Jim,
Thanks for the comments. I'll raise the servo a bit and all should work out. There were notes and a couple of pics in Hans's booklet, which I'm embarrassed to say - I missed. You haven't mentioned any lifting of the rudder shaft when the arm pushes, so I assume it is not an issue . Thanks again.
Richard
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Old Jan 01, 2013, 05:06 PM
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poltergeist's Avatar
Pomona, CA
Joined Apr 2007
706 Posts
My rudder servo and linkage is different as the servo is mounted in the same plane as the rudder post, so won't help you much. My rudder only has a very small bit (maybe 1/32") of up/down endplay. There is no way it can come off the lower bracket without the bracket being loosened.

Kevin
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Old Jan 14, 2013, 01:08 AM
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poltergeist's Avatar
Pomona, CA
Joined Apr 2007
706 Posts
Nice day of sailing today Got some fairly strong breeze (maybe 10+kts) for a short time. Neither Ed's #529 or my #551 took a drop of water below.

Kevin
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