Would a vertically retractable transom mounted rudder be useful for trailer sailors ranging in size from 20'-27'. The goal is to make trailering and shallow water maneuvering easier. Please respond if you think this is a good idea and if so, what must the system include in order to be competitve on the market. I am a senior in Mechanical Engineering and my senior design project is to design and produce a working prototype for a 1989 model Macgregor 26. Any suggestions or opinions would be greatly appreciated. Thanks!!
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Retractable rudder
Brian; Sounds like an interesting project. One consideration: Many Mac 26 skippers have found that an aftermarket rudder with 2 to 3 inches extended on the leading edge helps to balance the rudder forces and minimize "roundups". You'd have to rotate the rudder aft as well as vertical. OR, you could locate the vertical rotational axis a few inches aft of the transom. Good luck. David BSME UofA 1959.
Brian; Sounds like an interesting project. One consideration: Many Mac 26 skippers have found that an aftermarket rudder with 2 to 3 inches extended on the leading edge helps to balance the rudder forces and minimize "roundups". You'd have to rotate the rudder aft as well as vertical. OR, you could locate the vertical rotational axis a few inches aft of the transom. Good luck. David BSME UofA 1959.
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mrbill
aren't they are already 'retractable'
My 88 D is transom mounted, and most all rudders swing up, for shallow depth. *not sure how well they work in up position. -is the ideal like a jacking plate on outboard, where the rudder would be raised while still in forward position? I kinda doubt the price and complexitey of a system to raise the rudder while still down would appeal to many... (my guess is if it cost over $200, not many sales would result... just my opinion....
My 88 D is transom mounted, and most all rudders swing up, for shallow depth. *not sure how well they work in up position. -is the ideal like a jacking plate on outboard, where the rudder would be raised while still in forward position? I kinda doubt the price and complexitey of a system to raise the rudder while still down would appeal to many... (my guess is if it cost over $200, not many sales would result... just my opinion....
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Terry
Retractable?
Kind of like the idea myself, I have a 26M and it has a verticle retractable daggerboard. I guess it was cost prohibitive to do the same to the rudders, but likely still doable. I'd be interested in seeing how it could be done simply and on a budget. I found at the marina I moore at that LOA measurements for slip cost is done with the rudders up because that's how most of us are docked. That adds another 1-2 feet onto LOA. Verticle retractable rudders is one way around this.
Kind of like the idea myself, I have a 26M and it has a verticle retractable daggerboard. I guess it was cost prohibitive to do the same to the rudders, but likely still doable. I'd be interested in seeing how it could be done simply and on a budget. I found at the marina I moore at that LOA measurements for slip cost is done with the rudders up because that's how most of us are docked. That adds another 1-2 feet onto LOA. Verticle retractable rudders is one way around this.
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Brad
vetical rudders
Brian, check out older designs of geimini catamarans. Rudders are in a cage that slides out when hitting bottom held in with bugees. Worked as i had one. Another way is to create rudder in an arch, towing in under the transom. When they hit bottom, it pushes it back, but up so as not to break. Any rudder that does not have some safety built in will break eventually, or the pintel or gudgeon will. I recall one design that had a break away at the hinge, doubt if this is a good idea due to stresses found in bad weather. Brad
Brian, check out older designs of geimini catamarans. Rudders are in a cage that slides out when hitting bottom held in with bugees. Worked as i had one. Another way is to create rudder in an arch, towing in under the transom. When they hit bottom, it pushes it back, but up so as not to break. Any rudder that does not have some safety built in will break eventually, or the pintel or gudgeon will. I recall one design that had a break away at the hinge, doubt if this is a good idea due to stresses found in bad weather. Brad
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Dana_26D
Potential problem
On my '88 M26D I have copied the rudder Steve Vaczovsky's 26D rudder modifications, as shown on the attached link. About a quarter of the way down the page is a link to his mods page. The releasing clam cleat will allow the rudder to kick up if it strikes anything. Along with the backing plate and non-releasing clam cleat, it is much easier to raise and lower as I have a very shallow berth. I have found that if raised 90 degrees, in shallow water, the rudder works well going forward. Going astern it catches a lot of water and has too much leverage, making it hard to keep from locking hard over. A vertically raising rudder would solve this problem, however, it would not present enough area to the water to have any adequate steering effect in the shallows. I suspect that it may lose steerage if raised as little as half way up. Sorry that my opinion only raises a potential problem, but, it's cheaper to solve most problems on paper. If you just want to get the rudder up fast and steer with the motor then Steve Vaczovsky's mods are cheap and easy.
On my '88 M26D I have copied the rudder Steve Vaczovsky's 26D rudder modifications, as shown on the attached link. About a quarter of the way down the page is a link to his mods page. The releasing clam cleat will allow the rudder to kick up if it strikes anything. Along with the backing plate and non-releasing clam cleat, it is much easier to raise and lower as I have a very shallow berth. I have found that if raised 90 degrees, in shallow water, the rudder works well going forward. Going astern it catches a lot of water and has too much leverage, making it hard to keep from locking hard over. A vertically raising rudder would solve this problem, however, it would not present enough area to the water to have any adequate steering effect in the shallows. I suspect that it may lose steerage if raised as little as half way up. Sorry that my opinion only raises a potential problem, but, it's cheaper to solve most problems on paper. If you just want to get the rudder up fast and steer with the motor then Steve Vaczovsky's mods are cheap and easy.
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Brian
Clarify
The plan is to vetically retract as well as kick up. I believe this will allow for easier steering while in shallow waters or while trailering??
The plan is to vetically retract as well as kick up. I believe this will allow for easier steering while in shallow waters or while trailering??
An idea...
Assuming the aim is to provide a shallower rudder for motoring slowly in shallows, where the boat is upright and there is no requirement for lift and the consequent pressure on the rudder foil, maybe this has some merit. Something along the lines of a motor bracket, only in reverse. When you lift up on the rudder mount, the rudder moves aft ~3 inches and up. It is true that it will be a little further aft, but the axis of rotation would not change, the leading edge would clear the transom and it would raise up. I am thinking of the modified rudder, BTW. Just a thought.
Assuming the aim is to provide a shallower rudder for motoring slowly in shallows, where the boat is upright and there is no requirement for lift and the consequent pressure on the rudder foil, maybe this has some merit. Something along the lines of a motor bracket, only in reverse. When you lift up on the rudder mount, the rudder moves aft ~3 inches and up. It is true that it will be a little further aft, but the axis of rotation would not change, the leading edge would clear the transom and it would raise up. I am thinking of the modified rudder, BTW. Just a thought.
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