Telstar 26 MK1 Centreboard

[luigisante]

Many thanks Lou, Dimensions of the curved part that fits into the casing would be very handy. Does your centreboard have a groove for the ropes? Mine has two ropes connected by a loop one feeding forward through a hole in the casing and the other aft with cleats to tie them off but I'm not sure how or exactly where they connect to the centreboard.
Best wishes,
Cliff

I figure that the best way to give you my dimensions is in comparison to Pats diagram on his june 29th post @6:50am

Overall length Pats 57 0/16 = my 58 1/2"
Width of CB bottom Pats 15 = mine 16 1/2
trailing edge up to curve pats 15 1/2 = mine 17 1/4
top cut out at bottom pats 8 = mine 6 1/2
i measured the top of that cut out at 13", measured at the hight of the handle
Handle pats 9" = mine 9"
Measured from leading edge, across the bottom of the upper cut out to the back edge of the curve = 38 1/4

Here is a picture of mine.

My centerboard before shaping - traced directly from the original CB. Centerboard.jpg (25.18 KiB) Viewed 120 times

Let me know if you can figure it out from here.

Lou

[Evoxrs]

Thanks Lou, Your measurements and picture are very handy. I will redraw my CB and send you a copy. On your photograph the handle as you call it has a small projection a bit like a bird's beak what is that? Does it hold the rope arrangement for raising and lowering and does it have a ring or some kind of fitting? Also does any part of your centreboard have a groove for the ropes to lay in?

[luigisante]

My CB was not controlled by rope. It used a linkage that locked into blocks set on the top of the case. IMO, it was a virtually foolproof system. I think you can see it in some of the old brochures. I'll try to dig some up.

Lou

[Evoxrs]

Hi Lou,

Oh I see, well I can't imagine how that system would now fit into my CB casing.

I'm beginning to wonder if any two of these boats were actually the same!!! As a designer myself though I can understand how he must have kept wanting to improve the design, its the reason he now has the 28 so much more carefully worked out, I guess. Seems like we are kind of working with the prototypes...pretty good ones though arn't they one of the best boats on the water in my opinion? Its a bit like a developing class boat so it doesn't matter how we might improve them its all part of the process.

I am working on a CB design that doesn't bolt through the casing at all and falls under its own weight so that if it runs aground it will just lift up over the obstacle. When I have developed it further I will post it on here and I'll then probably keep the original as a spare just in case.
Thanks fopr your help,
Regards,
Cliff

[Ron]

Cliff -

I don't think Tony has built 2 of the 28's the exact same. Could be almost minor changes, but every new one seems to get something else. It's a never ending process. I've spoken to him about it. Every time he assembles a new one, he always sees something he could do to improve the next.

[luigisante]

Cliff -

I don't think Tony has built 2 of the 28's the exact same. Could be almost minor changes, but every new one seems to get something else. It's a never ending process. I've spoken to him about it. Every time he assembles a new one, he always sees something he could do to improve the next.

This seems to be even more of the case in the early boats. A spread of 10 hull numbers can be significant. The early boats were very rough from a building prespective. I can really see it refitting the cabin where you get to see the tolerances. Measurement of the same item can vary by an inch from port to starboard in as little as 8'.

[Evoxrs]

Yes, it seems Tony has developed a kind of cottage industry around the Telstars and is not so concerned about the quality of workmanship as he is about the continual improvement of the design. It can be dangerous if the quality suffers. I can see the same problems in my industry. Unlike the Bavaria's for example which are made almost entirely by computer. I bet the tolerances are within millimeters on those.

Nevertheless it really is the design that counts. A friend of mine was making 38 foot racing boats in Falmouth UK which were winning everything a few years back and a guy at the boat show asked him; "what's the difference between your 38 footer and the Bavaria 38?" His reply was, "in the Fastnet race....about six days!!! enough said.

Cliff

[petrel]

Cliff,

Is your centerboard shaped like Lou's with the addition curved "birds beak" section, or is it basically a rectangle with a semicircular top with a pivot at its center?

I seriously doubt that Tony built any of the pre 28 Telstar's the same. With the possible exception of the last few Telstars he built in the U.S. before the factory and molds were destroyed. I think the variation in the models says a lot about Tony's excellent innovative design skills. The non variable unfortunately is the poor quality of workmanship. Fortunately much of this can be addressed over time by the owners, which results in us each having a very unique and satisfying boat.

Returning to the discussion of the centerboard. Mine, and as I suspect most others are, is buoyant, and when down actually adds buoyancy to the boat. An unrestrained board will not fall down unless the boat is out of the water - not a good idea because it can cause damage to the board and/or hull. In the water and unrestrained the board will float back up into the centerboard case, so restraint in the down position is necessary. Because I sail in shallow waters I created a restraint system with a quick release which releases the board if I hit the bottom too quickly.

Hope this helps
Geoffrey

[Evoxrs]

Hi Geoffrey,

No mine doesn't have the beak shape I don't think. The problem is I don't have that bit any more the only bit I have is the end of the CB with the pivot hole all the rest floated off with the tide. I only saw the top of the centreboard through the top of the casing once when I was freeing the downhaul rope.

I agree with your comments about the owners being able to improve the boats, it does make them much more appreciated if you have had a hand in its construction or repair, however small the contribution might be. I can see some on here have made big improvements as well, which is great.

Regarding the Centreboard floating up, yes I see your point. Of course this is always assuming you have a timber centreboard. My intention is to make a board in which the central part is a 5mm stainless steel plate with timber cheeks and this will then naturally swing down under its own weight. As you rightly say this will still need restraint to stop it damaging the slot at each end. I am thinking about some kind of counterbalance or to attach the downhaul and uphaul using a spring balance system (like that used to weigh luggage in its most basic form) then one could vary the amount of force required to keep the board in position. I would then refine this idea into a more elegant spring mechanism. I sail a dart 18 catamaran as well and the rudders on those kick up if they hit the ground at speed. They have a groove in the foil into which a spring loaded plastic roller is held. It requires a hit at speed to dislodge the roller, a bit like a roller door catch and then the rudder swings up. This way the rudder doesn't swing up under the normal force of the water at say 15knots but its a complex mechanism which should get annual servicing. Is your quick release something like this?

I also want to hinge the centreboard part separately from the handle which would be rigidly fixed into the casing and this way the pivot could be designed so as not to penetrate the casing at all and the risk of a leaking casing would not occur. I know that Tony has devised something like this on the 28 but that mod would involve a new casing and that is big job on a 26 or 8m.

Cliff

[Evoxrs]

Many thanks Lou, Dimensions of the curved part that fits into the casing would be very handy. Does your centreboard have a groove for the ropes? Mine has two ropes connected by a loop one feeding forward through a hole in the casing and the other aft with cleats to tie them off but I'm not sure how or exactly where they connect to the centreboard.
Best wishes,
Cliff

I figure that the best way to give you my dimensions is in comparison to Pats diagram on his june 29th post @6:50am

Overall length Pats 57 0/16 = my 58 1/2"
Width of CB bottom Pats 15 = mine 16 1/2
trailing edge up to curve pats 15 1/2 = mine 17 1/4
top cut out at bottom pats 8 = mine 6 1/2
i measured the top of that cut out at 13", measured at the hight of the handle
Handle pats 9" = mine 9"
Measured from leading edge, across the bottom of the upper cut out to the back edge of the curve = 38 1/4

Here is a picture of mine. The attachment Centerboard.jpg is no longer available Let me know if you can figure it out from here.

Lou

Just to conclude my centreboard issue I attach my final drawing based upon the info kindly provided by Lou and Pat and adapted to suit the dimensions of my boats casing. I thought this might be of use to someone out there. We are metric now of course but if anyone wants the dimensions in feet and inches let me know its a simple matter to reconfigure the drawing. Also if you want a hard copy let me know I'll send you the file and you can print it to scale

CB 14.07 rev A_1.jpg (80.85 KiB) Viewed 89 times