Lee Helm on my Olson 34

[sjconnor]

I was wondering if anyone might be able to advise a possible reason / solution to my pretty bad lee helm I've had since owning my Olson 34 even with a full main and 110 jib.

One experienced friend has advised that I could alter the rudder - either reduce the size of the leading edge or increase size of the trailing edge.

Any thought and advice would be most welcome, and any dimensions of stock rudder would be most appreciated also.

attached is a recent pic of my current rudder.

Thank you,
Simon.

 

[Loren Beach]

For comparison, I am looking around my crowded hard drive for pics of ours. Found one from a few years ago. Will keep looking for a "profile" pic.
(Gotta learn how to better "tag" photos one of these days....)

Loren

ps: edit: found the rudder photo.

 

[Emerald]

How much rake do you have on your mast? Have you gone through your rigging?

 

[HughHarv]

Lee Helm

As I recall, lee helm is due to your sail plan being too far forward of your keel which would lead to the bow blowing off instead of heading up. In that case, one would need to somehow move their mast/sails a little further aft. Does your mainsail set well, have enough draft in the right place? If mainsail looks good you might be able to rake the mast aft a few degrees by tightening the backstay, moving the mast base aft, or by adding more area to the mainsail, etc.

On another thought, does adding more to the leading or trailing edge of rudder change the angle of the rudder in the water so that you have less frictional drag? Or does the angle remain the same and the increased size of the rudder just create additional drag?

 

[Loren Beach]

Hmmm... well, it IS keel stepped.

I just had a thought (sometimes this happens, but as I age, not so much...).

When I replaced the original wood mast wedges, I kept the spar about where it was - centered. There was some, albeit not much, room to move it in the fore n aft plane. Maybe about a half inch all told. A little movement there would equal quite a bit 50 feet up.
The stock Kenyon base does not have provision for movement, IIRC.

Hopefully we can get some other owners to weigh in on this.

Regards,
Loren

ps: edit: in studying the picture, I just noticed that Simon's upper blade profile seems different than mine. Trick of the eye, maybe. (?)
pps: second edit: More I look at it, the whole side profile just looks different, like the front part has maybe less area. That would give less "balance"...

 

[Emerald]

I feel like the rigging should be first on the check list. Let's assume that the original designed rudder resulted in a nicely balanced boat. I've never been on an Olson 34, but Loren should be able to confirm this.

 

[SASSY]

Lee Helm

The 1987 E-34 calls for 6" of rake at the mast head based on the owners Manual. Do you have sag in your headstay? How is the shape of your main? I would pursue tuning the rig before making adjustments to the rudder. I have heard of some people putting a silver dollar under the leading edge of the mast at the base to rake the mast but I have not tried that myself.

Good luck.

 

[e38 owner]

rake

This may also apply to an Olson 34. Many boats in that design era need quite a bit of mast rake. In addtion to my Ericson I have had a J22 and Hobie 33. Both of which the racing quides called for extending the forestay to get quite a bit of rake

 

[Rhynie]

Simon,
Mast rake, as has been mentioned, would be the most obvious starting point to try some adjustment. Sail trim could be a another factor if you are over trimming the headsail and/or under trimming the main.

Weight in the bow, think of how the boat sits in the water, would relatively move your center of effort forward and the center of lateral resitance aft, but it would have to a significant amount of weight.

I would ease the headstay a couple inches and take up on the back stay, and see if that changes anything. You will also need to move the genoa car forward a notch or two

 

[sjconnor]

Lee helm, rake and rudder

Thank you all for your inputs.
I also had the same thought as you Loren, I made up the original wedges, and centered the mast, I could angle the mast backwards by puting a single wedge in the front of the gap.

Everything that everyone has said has made perfect sense also and I shall look at my rigging, mast rake etc so thanks again for your advice.

The friend I took out sails in the World Championship J24 and he's had the additional benefit of looking at my mast rake and feeling the horrible pressure on my rudder as I took him out on the helm for 2 hours on different tacks in about 15 knots breeze. He feels strongly that the rudder has had too much on the leading edge, and he's seen this before on another boat, took the rudder out, modified the balance and it resolved the problem.

What he suspects also sounds logical, I found this elliptical rudder of an Olson 30 (see attached) the leading edge is 5 3/16 and trailing edge is 15 9/16. thats about a 1:3 ratio. This is consistent with some profile pics of other rudders, that I've seen recently. By the looks of my picture however, my leading edge looks a lot closer to a 1:2 ratio, and it looks like it might taper off too quickly on the trailing edge too.

I guess there's only one thing to do - try everything !

 

[ted_reshetiloff]

I have yet to hear of any other o-34 owners complaining of this problem which makes me think it is not a design problem unless you dont have the original rudder. I think you rig must be out of tune. Below is one of the best tuning guides I have seen and while it is from Selden it can be applied to just about any aluminum mast.

Note to Site Admins maybe we can get this guide into the docs section?

http://www.riggingandsails.com/pdf/selden-tuning.pdf

 

[Czech Mate]

Ted:

Thanks so much for posting this link. I have an 1975 E32-2 and have been struggling with correct tuning for some time. It looks like there is a wealth of information in this article. I am printing it as I write this reply. Should have some interesting reading material for tonight.

Thanks again,
Bill

 

[ted_reshetiloff]

Selden hands these books out at the Annapolis Boat Show every year. When I was working in the rigging industry we often gave them to customers. One note of caution on their tuning advice. They call for pretty tight rigging and many production boats are simply not stiff enough to handle this tension. If you find after tuning per this books advice that cabin doors are binding that did not used to bind you will want to consider backing off the tension some.

 

[sjconnor]

not a design issue

Ted - I have to agree. I never thought for a moment this would be a design issue otherwise this would never have been such a popular boat.

I suspect this is a modified rudder. The original owner cut the transom off (see pic) and shortened the rudder stock and theres nothing about the rudder dimensions that looks standard at all when I compare with other standard rudders. As mentioned the leading edge is typically just less than 25% of the total width, whilst mine is more like 36%, a heavily proportioned leading edge puts a lot of pressure on the tiller

What a great response on this thread with such useful information and in only a couple of days. I'm very impressed.

 

[ted_reshetiloff]

Ahhh well that explains a lot. Although I have seen a lot of balanced rudders with the post at 30%, 36% is probably a bit extreme esp when you throw up a 150% genny or a big kite. Have you spoken with the PO at all about this problem? Did it develop the minute he changed the rudder? Chopping out the transom in and of itself would do nothing to the balance of the boat that I can see other take some weight out of the ends which might reduce pitching? Did the PO modify or replace the rudder? Can you get the OEM rudder back in the boat?

 

[sjconnor]

Rudder rebalance

Ted this all happened in or around 1985, I've no idea how to contact the original owner, and this rudder is all I have.

I removed the rudder today and took some more measurements. Over the next week or so I will reduce the leading edge and build out the trailing edge so that its about a 30:70 ratio, then reinstall and try her out on the water. If she feels good then remove and smooth, undercoat and antifoul, otherwise if still not balance, remove, and adjust and try again until I'm happy.

 

[e38 owner]

Templates

I was able to get fairing templates for my E38 and J22. It might be possible to get some fairing tmeplates for a stock Olson 34 or diffently for a boat that is close. Foss foam may have them., Compu Keel also may. Maybe someone one this site would know. http://www.computerkeels.com/COMPKEEL.HTMhttp://www.computerkeels.com/COMPKEEL.HTM. Maybe the can send you the measurements first to see if you have the correct rudder.

 

[Loren Beach]

Ted this all happened in or around 1985, I've no idea how to contact the original owner, and this rudder is all I have.

I removed the rudder today and took some more measurements. Over the next week or so I will reduce the leading edge and build out the trailing edge so that its about a 30:70 ratio, then reinstall and try her out on the water. If she feels good then remove and smooth, undercoat and antifoul, otherwise if still not balance, remove, and adjust and try again until I'm happy.

Very Minor nit pick: date of change more likely '95, since all Olson production was from mid '88 to sometime late in '90.
One other life lesson I take from all this is that sometimes (very occasionally) a change is not for the better. Most changes, like the improved rudders done for some 70's Ericsons seem to be excellent, and also the effective draft-reduction keel mod from Mars Metals. Matter of fact, if we ever hit a small Lottery we might do a fin-n-bulb keel change to reduce our draft from 6 to 5 feet. Winning odds are not too favorable, though.

One other rudder-ish note: the factory stock O-34 is actually a Schumacher design, and it's only "shortcoming" (short pun intended) is that it was the same rudder he designed for the O-911S. I suspect that's why a few owners subsequently opted for a custom deeper rudder.

Regards,
Loren

 

[Loren Beach]

I was able to get fairing templates for my E38 and J22. It might be possible to get some fairing tmeplates for a stock Olson 34 or diffently for a boat that is close. Foss foam may have them., Compu Keel also may. Maybe someone one this site would know. http://www.computerkeels.com/COMPKEEL.HTMhttp://www.computerkeels.com/COMPKEEL.HTM. Maybe the can send you the measurements first to see if you have the correct rudder.

Perhaps seed material for a new thread... but you make me realize that, as these boats age and original paperwork disappears, we may all want to establish a regimen of doing at least a three or four-level template collection of all of the stock rudders for Ericsons and Olsons.
This would, in ye olden days, involve a plywood form, tape measure, and creation of an offset table, or similar.
I suppose that there must be something a bit more high tech now... maybe an App for the iPhone?!


Loren

 

[sjconnor]

1995 indeed

Loren, you're right it would have been in 1995

Just had another thought, when I bought the boat the mast was lying on the deck and I stepped it myself. With no experience whatsoever I did nothing to rake the mast with wedges or anything under the mast bast and there was nothing attached to the end of the aluminum section at the foot of the mast to assist in tilting.

It's quite possible that that previously the mast was raked backwards which may well have balanced the rudder. This was a boat that was a frequent high performer in races so I doubt that wouldve been possible with such an un-balanced rudder setup.

So another question to Olson 34 owners - does the mast have any angled mast base or anything under the mast to tilt it backwards ?

Do you use any specially designed wedges where the mast comes through the deck to push it backwards ?

Regards and many thanks,
Simon.