tiller head assessment

[ebb]

Would like to initiate a discussion on the bronze A/C tillerhead which attaches to the top of the rudder shaft.

Capt. Walbert's additions to the sides of the fixture (on Kestrel, Ariel #1) got me thinking again about this imho heavy clunky piece of bronze. Seems evident that if this tiller head is in Ariel #1, as well as Ariel #338, have to assume the fitting is on most if not all the rudder shafts between.

First of all, there is a lot of weight cantilevered off the top of the 1" shaft.

Second, the casting has very little room for the wood of the tiller. On 338 the space left for the tiller is 1 3/16" by 1 3/16" square where the wood goes in to be bolted into place. Makes me wonder if this casting was meant for a metal tiller? Strong arguement here for an aluminum one.

Or, why have such a HUMUNGOUS fitting for such a skinny tiller?

Third, because of the cramped dimensions of the channel the three bolts that are meant to hold the tiller on are almost in a straight line. Not good with wood. I'll wager that many a tiller was split there at the 'heel' when somebody leaned on it! Of course you'd make the tiller with more meat underneath, but that concentrates the holes for the fastenings along the top. Not good design.

Fourth, When you lift the tiller up because you want to steer standing or sitting on the coaming or avoid knees - the amount of bearing surface diminishes between the fixed head and the hinged tiller part.

Fifth, imho the rectangular design of the hinged part is wanting.


OK, let me put forward two ways to improve this situation with a new casting. A casting pattern for this one hinge piece would be simple to make.
A wider deeper channel to hold more tiller end and have more bearing surface when the tiller is raised. I believe the casting thickness could be reduced to 1/4". I would think 2 1/4" wide minimum - with the sides at least 1 3/4" deep. Making a revised fitting of around the same 5#(total) weight.


Many tillers these days are made of laminated strips. With the right glue it is a strong tiller. You can have a emphasized 'S' shape to get the tiller out of the cockpit better. With the design we have the fasteners go thru the width and therefor thru the glue line of the strips. Not good. But a solution is relatively simple.

The second improved casting would have the flanges for the bolts on top and bottom of the tiller. You can easily see this by imagining the flat top of the channel we have now with a corresponding bottom with the sides left OPEN. It's a matter of designing a strong and pleasing shape. This is the way I'm leaning.....

If anybody is interested in such an 'improvement' this is the place to talk about it.

[Bill]

Being a traditionalist . . . let me point out that this tiller head fitting was used on all Pearson yachts of the era. Ditto the rudder shaft.

The only "problem" that I've encountered with the bronze fitting and wooden tiller has been when the tiller is lifted and the "ears" on the tiller fitting come off the tiller head leaving them unsupported. Over time, this results in bent and eventually broken tines. The least expensive fix is to replace the stock tiller with one who's center rises higher allowing one to use the tiller while standing without lifting the tiller fitting off the tiller head.

A more expensive option is to cast the tiller fitting in a new material such as stainless steel . . . Or replace it with a ss after market product. But then we have stainless to bronze contact on the rudder shaft . . . :confused:

Oh yes, as I recall, Zoltan Gyurko made it to the Med using the stock fitting. ;)

[bill@ariel231]

Ebb

I've been wrestling with the need for new tiller hardware for A-231. we have before us three sources off the shelf...

1. The ensign/electra/ariel/commander tiller casting based on the original rostand pattern is available from ensign spars.

2. Bristol Bronze offers something very similar to the rostand but the tiller head is through drilled.

3. Historical Arts in Utah doesn't have our model in the pattern collection, but the've got the next size up. I've ordered the same shape originally made for a 1.5" rudder shaft. It has more room for a wider tiller. I expect it will be here in a month or so...

I'll stick with the original style for now but just a wee bit bigger (option 3)..

cheers,
bill@ariel231

ps... "to quote ebb: Makes me wonder if this casting was meant for a metal tiller? Strong arguement here for an aluminum one." A-231's previous owner replaced the wood tiller with an aluminum copy. nicely made too, except for the dissimilar metals problem... the aluminum turned to powder and split the bronze casting!

[bill@ariel231]

Ebb

Historical Arts has one other tiller option (originally offered for a 1.25 shaft).

the tiller head appears to have been meant for a vertical rudder stock withthe tiller at 135degrees to the rudder stock (like the bill shaw pearson 26). there is a lot of meat in the tillerhead that could be cut back to allow the tiller to rotate down to 90 degrees and still allow the tiller to be fully in contact at 135degrees to the shaft.

the dimensions on this one are (11" long, 1.75" wide tiller (inside), 1.25" shaft- although it can be drilled for 1")

cheers,
bill

[ebb]

Howzit goin Bill?
Gotta get into the mind of your fellow traditionalist who designed our tiller head. Could say it's not over-engineered. Depends on MASS for strength - and yet, as you point out, there is a problem with it.

To support a total traditionist view, one could say that the fitting is fail safed in that if the EARS are strained it will not mess up the part of the fitting on the rudder shaft. You could also say that the part on the rudder shaft on Little Gull's tillerhead is out of round and worn - requiring shim material to make it snug. There is an ancient discussion on this subject somewhere here in the archives.

The tillerhead is problematic. And is a compromise like more or less everything on a boat. The part of me that is not traditional feels that much of what is traditional needs to be questioned - or it becomes a trap. I don't find that investigating a bronze fitting with intent to improve it any different than say changing a slug-footed mainsail for a loose-footed one. If the tillerfitting can't be made better, than so be it.

I do feel that as far as Pearson was concerned the tiller head worked OK. It stayed problem free, for the most part. This doesn't make it a great fitting.
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Changing out the traditional A/C rudder head fitting for a larger one to get more width for the heel of the wood tiller is, of course, unacceptable. It's a weight problem. The current fitting already has too much weight to it.

A entirely newly designed 316 stainless fitting would be fantastic! I'd bet it would less than 1/2 the weight of the bronze. And it would be perfectly happy on top of the bronze shaft. There'd be a lot of work in the modeling of the pattern(s) for the foundry.
Little Gull has new cast bronze fittings all over. They are relative simple to shape and have made. In fact they are mostly but 'improvements' on the traditional fittings that came with the boat.

I'm convinced that having the fastenings for the wood tiller on top and bottom, rather than thru the side would be a better design. It must have come up at the Pearson plant. But there was no incentive to make the improvement. It would have added to the price of the boat. The design probably exists somewhere. We're not inventing the wheel here! Something that would be acceptable to the traditionalist. The channel does hold the heel of the tiller so that sideways strain won't break the tiller - unless the tiller breaks at the fitting. I'll bet this has happened.

The only answer is more wood at the fitting. You might argue that bolts going thru the top of the tiller would be just as likely to split the tiller if it is strained to breaking. Not a liminated tiller.



The Ronstand pattern at Historical Arts looks like the fitting I have. Exact replica. I still find it wanting, still find it too much of a compromise and wrong for properly fitting a wood tiller to.

So we'll see.
Historical Arts has traditional skene chocks too. Skene chocks are line UNfriendly,
tho the Ronstand pattern they show in the thumbnail on their website is not as bad as some skene chocks that tradition puts into the market today.
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bill,
That pipe tiller fitting is right-on! There is no reason why a modified version of those ears could not be part of a modified version of our fitting. IS THERE?
NO reason that the tines (let's call them) that hold the wood tiller could not be widened on a new pattern. IS THERE?
And ebb says rotate the tines 90 degrees so you can hold a laminated tiller better.

[bill@ariel231]

I can't say i've seen a tiller casting with a frame top and bottom.. in such an arrangement, all of the load on the tiller will be born by the bolts. While it would clamp a laminated rudder well, I'm not sure the result wouldn't just be a vertical split thru the tiller along the line of fastners (maybe you could wrap the butt of the tiller in two layers of 6oz cloth before installation).

I'm going to try the 12 inch long version from the Vanguard. I've held one at a marine consigment shop, it wasn't much heavier than the original 8.75" version (just a couple pounds) and it has room for a 2 1/16" tiller. which is the size i'm using today (more non-standard hardware)...:)

[ebb]

bill,
Agree on your accessment on vertical fasteners thru the tiller.
Although the same arguement works for horizontal fasteners thru the tiller!
It's apples and pears.
On the laminated tiller, I believe horizontal fastners would be more likely under stress to delaminate the tiller than vertical. AGREE?

The pin connection between the two parts of the tillerhead is the KEY! That's right. The original fitting is obviously quite strong enough as the fitting has lasted well enough these 40 year. The thickness of the casting has provided plenty of surface to surface bearing of the moving parts.

{I believe an essential upgrade is to install a 5/16" bolt that is threaded ONLY where the nut is. IE the bolt is smooth thruout the moving parts. This will help take some play out of the joint. Taking the play out will strengthen the joint.} A new O-ringed sleeve bearing at the top of the rudder tube is essential as well.

Jose Bergamin said "Tradition simply means that we need to end what began well and continue what is worth continuing." There is room for improvement if this statement holds. What is the weight of the 'larger' fitting? That's only a 1" shaft there.

The thing to do is make a model of what you think holds the tiller end best (it may be FOUR sided) and then see if you can make it fit the piece that sits on the shaft. I don't think there is much engineering in this. No unassailable traditional magic here.

At best the moving piece, the tiller connection, of the Ronstand fitting is AWKWARD and ought to be fixed, so that tradition can continue;) . Without innovation, the Ariel is a corpse.

[bill@ariel231]

My current tiller fitting looks a lot like the 1.25" one shown above. I've not had a problem on the tiller fitting end. The problem my old (original) tiller head has play in the bolt that connects the tiller to the tiller head. (enough that my simrad autopilot gets confused).

I haven't had a problem with tiller delaminaition (maybe its dumb luck, maybe it's the cover that keeps the varnish in good shape).

[ebb]

Elongated holes. Comes from a bolt too small. The threads on a bolt are smaller in diameter than the size of bolt. And the smaller bolt allows moment where you don't want it.
The designers left NO fudge room to fix this.
I would NOT clean up elongated holes whatever by redrilling with a 3/8" bit. Too large. You got 5# of bronze tillerhead that depends entirely on a dinky 5/16" hinge pin/bolt!!!

What's your prognosis on this?
I don't feel there is enough meat around those knuckle holes for ANY enlarging.

But if you have to SAVE the fitting, and can set it up to drill straight thru both pieces, could consider using the next size up from 5/16" - like 11/32" if you can find the bit, if that is enough to ROUND the hole(s) again.
(Then you'd have to get a machineshop pal to turn a 3/8" bolt down. And you'd probably have to put threads on it for 5/16" nut.)
No reason for a clevis pin not to be used - is there? Be a little wierd, cotter pins and all, but you could get the knuckle tight again. If the clean-up redrilling worked.

Or go metric. Maybe there's a 8 or 8.5 mm bolt (matched to a mm drillbit) that would work.
And maybe 316L pin could also be used there, if no silicon is available.
Or turn a bolt down custom, cut the thread off and drill for the cotter on the open side.

Like something's off-the-shelf.

What do they want for a new tillerhead? $250?
If I bought a new bronze tillerhead from H.Arts, be damn sure there was absolutely no play between the two pieces relative to the pin. The bolt/pin should be totally snug. And there should be no wiggle room between the two pieces where they move up and down. That stuff will happen too soon enough. The tiller acts as a lever, and it's all bearing on a small pin! The tighter it is the longer it will last. (hey Carl, WHO designed this thing?)

[bill@ariel231]

The Historical Arts part was quoted at $230. Looks like i'm the first one to place an order (of note: Ensign Spars offers the original size for $210 in bronze a bit more in chrome. Bristol Bronze's take off on the subject is $285 or so).

My old tiller head is shot. (bent ears, elongated holes plus a couple set screws that keep it in place on the shaft) not enough meat to fix without welding, but it will work as a spare.

There is a consignment shop in Mystic, Ct. with an original (in chrome) that is drilled for 1.5". it's interesting to look at but i don't have the spare time to deal with creating shims and making that one fit.

[ebb]

Be most interested to hear your take on the fitting.
Obviously I'm not a trusting soul.
Especially if these Arts people do mostly architectural castings.
This is an important WORKING piece of equipment.
The patterns they cast from should have been remade new. Expensive!
There is close tolerance machining involved here... they can not be sloppy.
Let's hope they have the alloy correct!!!

It should be 655 imco.

[bill@ariel231]

The've been in consultation with IYRS so we'll see if that means anything. The patterns are the rostand originals and look to be bronze or aluminum depending on the part. The casting will be done in a sand mold, then sanded and machined. The've got the original prints for the cut sheets and machining specs. So i'm hopeful, but this is an experiment and could go awry.

I'll post pictures when I get it....

[ebb]

weight correction.

The 8" long (measured from the center of the bolt:p ) Ronstan pattern tillerhead from #338 weighs in at 4.19 #.

1" bronze rod (338's is silbronze) = 2.88# per foot
approximate length of rudder shaft is 6'.

Interesting that our fiberglass boats have a mahogany and bronze holdover from the yachtzy wooden boat days. I guess IYRS could have SOME interest in our craft but ONLY the rudders.
I don't believe they have a single class on frp restoration, do they?

At 50 or 60 years now for glass and resin boats, it has to be time for a boat school to appear that is dedicated solely to THEIR care and study. We need a set of rules, we need to preserve the old tools for young middle class conservators-to-be on what are the proper methodologies when restoring isophthalic polymer watercraft.
I sure could use a course on estimating time and costs of a job or work. Not kidding.

[bill@ariel231]

IYRS is focused on the wooden boat school/business for now (from beetle cats to the 1885 mega yacht coronet). This is important stuff. My hope is eventually someone with vision (and money) will see that there are other designs (made with other materials) that are also worthy of rememberance and preservation...

On the estimating side... I now take my best guess, double and add half (this thumb rule works for money or time) ;)

[ebb]

You mention Bristol Bronze back in post three.
Wouldn't be surprised that they too would not have a tillerhead on the shelf and would by order have it cast.

Don't know if Roger Winiarski is still at the helm. Had castings made by him, he certainly shared information and time over the phone. He seemed to like talking about his art. You can get castings finished at any stage. More finished, more $$$. He maybe could drill a 1" stopped hole for the shaft in the head you were interested in. The keyway might be difficult.

Bristol Bronze has reputation and everything going for it.

Haven't thought it thru but is it a serious problem if the shaft does go thru the head? How is the B.B. tillerhead held to the shaft? A horizontal key?

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Another curiousity is the 'squeeze clamp' feature of the Ronstan tillerHEAD.
338's has a split tapped hole with a 5/16" machine screw. This clamp action was to attempt to snug the head on the shaft and make sure the key stayed in. (It would have to be quite malleable bronze for anything to move. It's inactive in my fitting and a blade of some sort has to clear the 1/16" wide slice where it 's meant to be squeezed. The hole in my head has had serious stress in its working life. Yes, indeed.
Think I'm looking at a new fitting too, if I was smart........but, since you're doing the homework, bill.....
Gentle persuasion to remove the screw has not worked. It may have galled in there. I'm also not persuaded that a machine screw is effective in moving the miniscule gap - because the screw has to have threads clear to the hexhead for it to be able to draw the clamp tighter. And that is serious THICK metal there!
It was Ronstan's right choice.
Bet $10 that H.A. puts a bolt and nut thru it.

I'd keep a critical eye on how they finesse this all important fitting.
Their online catalog shows one model with a jog in it. Not our pattern.
Only Everdur is tuf and soft and strong enuf for this tillerhead duty. IMCO. I would not accept one made in brass.

[bill@ariel231]

Roger Winarski (BB) had an example of his tiller offerings on the shelf at the Maine boatbuilders show. The nearest match is a clone of the Rostand pattern with the 1" hole thru drilled (you can see a sketch in his on-line catalog). Thru drilling reduces the cost of machining. technically i don't see a problem with that approach. in fact it might make removal easier since a bearing puller could be used to extract the tiller head if required.

I agree that 40 years on, the tiller head clamp assembly doesn't get the job done. Mine's currently tapped for two allen screws that bear down on the keyway. If for some reason my new part from Historical Arts doesn't clamp adequately... it will get the same allen screw fix.