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#1
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Bushings, bearings, tomatoes, tom-ah-tows... the question is what does
the boat you want have, and what shape are they in. Many boats have rather fancy double-race needle bearings for the lower rudder post "bushing." The loads here can be tremendous when sailing hard. Michael wrote: Think "balanced" vs "unbalanced" rudders....power steering vs manual. The balance area of a rudder reduces the perceived load on the helm, but does *not* reduce the load on the rudder post. I am not aware of any production boat that was built with the bearings you suggest. I though such beasts do exist for rudders.. Probably not in the 30' size range. Fancy racing boats have top-notch rudder post bearings, and of course bigger boats have to have bearings appropriate to the load... if they're well designed of course... It's a worthwhile upgrade to a boat that will spend a lot of time sailing hard on autopilot. I doubt that anyone has ever purchased a boat having everthing they want - unless it is custom built and designed for them. Even then, you just can't get everything. I think there's a law. Again, IMHO is you can't do a job like this yourself you should be considering buying the boat. If you don't have the knowledge, at the vey least, how will you know if the boatyard does it *right*? That can be said in virtually every situation and realm of anything just not boats... A wild guess is that 80% of boat owners dont know how to do this or 80% of any other work that may be required to be done, yet they own boats. IMHO that's a wild overestimate. Most boat owners I know (mostly mid-size sailboats) know how to do a wide variety of technical things and all basic maintenance. The stuff that gets done by hired help is either really demanding & technical, perhaps requiring special tools... like testing injectors or timing injector pumps... or really tedious & awfule, like sanding off old bottom paint. Standing rigging has little to do with the designer ??? In terms of it replacement, sure designers initially determine the original config. and I have yet to see anyone change that (from an original design aspect). I have. In a very few cases did it turn out to be a wise move. ... Very rarely would the design of the standing rigging be changed on a production boat. Depends on who is doing what. A a relatively common change is adding an inner stay for a staysail. What I had in mind is the excessively salty type who brags about "upgrading" his standing rigging to the next larger size, because it so macho to brag about sailing in high winds. The issue here is that 1- rigging is sized to the boat's righting moment regadless of wind strength and 2- heavier rigging will dregarde the boats performance and 3- because of the difficulty in getting the tensions correct, may actually weaken the overall rig & bring down the mast. The Guy who circumnavigated on a Cal 25 did upgrade the standing rigging to 1/4" and did extensive mods... Yep, Dave Martin. He stayed in Oriental, NC for quite a while. Some of what he did made good sense... putting on larger standing rigging did not. In fact (as I said) from an engineering standpoint it can be harmful. Where does all the added stress from this stronger rigging go? It doesn't disappear! Yes there are downsides to upgrading the standing rigging to a larger size, one increment in size would not make a difference Yes, it would. There would be a difference in weight aloft, in windage, in stress generated from the additional tension needed to keep that heavier gage rigging from shock loading, and in any event (as I said) the standing rigging loads are determined by the boat's righting moment. The strongest possible wind will not impose any more strain on it. However the heavier gage will require greater tension and will have less elasticity and will probably overstress the chainplates and will definitely place a greater compression load on the mast. I have never yet heard of anybody putting on a thicker mast because they want a tougher more seaworthy boat. In short, putting on heavier standing rig is good *only* if it was undersized originally. In any other possible case, it is detrimental to the boat's performance and seaworthiness. Period. How long should standing rigging last, at what point should you consider its replacement? Depends on type & service. The thing that really kills standing rigging is crevice corrosion in the swaged terminals. That's by far the most common point for failure. Another common one is roller furlers unlaying the forestay cable. After that would probably be fatigue from improperly toggled turnbuckles. I have also seen a rig come down when the jib sheet pulled out the cotter rings from the clevis pins. ... One guy in New Zeland actully uses galvinized standing rigging, A lot of people here use galvanized, too. Here? Where? I'm on the middle US East Coast. I have personally have not seen any on a standard production boat retro fitted with galvanized. I have. Not all that common, but maybe there's a higher percentage of people that aren't embarassed to shop at the farm & truck supply around here. .... But I do see the postive aspect of its use. I would rather replace it more often at that cost than figure the SS rigging will last as long as the rest of the boat. Get Sta-Loks. You'll never need to replace anything but the very inexpensive cones. If the wire itself is slightly stronger, it's also less flexible and the connections are correspondingly weaker. Not necessarly...rod rigging isnt meant to necessarly be flexible Yep, that's a different can o'worms. I don't have much experience with rod rigging... in fact none at all with replacing it, specifically... but it seems to be much longer lived due to the lack of swaged terminals... and anyway not very many 30' and under production boats have rod rigging, do they? As far as I am concerned a saildrive unit is essentially an outboard with more negatives. Like what? The newer saildrives are great. Less trouble, more efficient, and neater installation, than a conventional inboard.... you can put both the engine weight and the prop in more advantageous locations. The advantages of an outboard are 1- cost 2- winter storage in your closet 3- service by removing it to the shop 4- maneuverability (*if* the installation is such that the helmsman can swivel it) Pretty much everything else about them is a negative. Fuel economy & heavy weather performance are terrible. Very true, but then risk of theivery or submergence or damage is higher; reliability is often lower too. Point for the lazerrete config..... Putting the OB in a lazarette might reduce the chance of theivery, but it increases the chance of flooding... those wells get a surge up in them at every wave, your engine could go under water 500 times and you wouldn't see it. Many of the also amplify noise, and choke the engine. They keep that traditional counter stern looking sweet, though. That's been my experience with a dozen or so boats equipped with outboards in wells. YMMV In my case, I have always bought bargain-basement boats for very cheap (ie within my budget) and fixed them up myself. But it's really sailing... both racing & cruising... with my family that I enjoy most. It's the means to an end. The economic advantage doesnt always outweight the practical downside, mileage will vary....Boat repair can be a hobby to a degree. And it also gives you a boat that you know all about, and can fix, and can rely on. Much so called "wisdom" is perception also:}} "Genius is limited and stupidity is unlimited" That's an excellent quote. One of my favorites is "The trouble with the world is that the stupid are cocksure and the intelligent are full of doubt" --Bertrand Russell Fresh Breezes-- Doug King |
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#2
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On Mon, 04 Apr 2005 23:12:53 -0400, DSK wrote:
Michael wrote: Think "balanced" vs "unbalanced" rudders....power steering vs manual. The balance area of a rudder reduces the perceived load on the helm, but does *not* reduce the load on the rudder post. /// Fresh Breezes-- Doug King Hmmm...seems to me that the steering torque on a rudder can be reduced, zeroed or reversed - depending on the balance area fraction selected. The rule of thumb, I seem to recall is 25% area forward for minimal torque - more than that and the torque is reversed, giving unpleasant positive feedback effect. Brian Whatcott Altus, OK |
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#3
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On Tue, 05 Apr 2005 03:24:46 GMT, Brian Whatcott
wrote: On Mon, 04 Apr 2005 23:12:53 -0400, DSK wrote: Michael wrote: Think "balanced" vs "unbalanced" rudders....power steering vs manual. The balance area of a rudder reduces the perceived load on the helm, but does *not* reduce the load on the rudder post. /// Fresh Breezes-- Doug King Hmmm...seems to me that the steering torque on a rudder can be reduced, zeroed or reversed - depending on the balance area fraction selected. The rule of thumb, I seem to recall is 25% area forward for minimal torque - more than that and the torque is reversed, giving unpleasant positive feedback effect. Brian Whatcott Altus, OK On second thought does a balanced rudder put less force on the rudder post or just on the tiller? Wild guess, probably both? |
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#5
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On Tue, 05 Apr 2005 03:24:46 GMT, Brian Whatcott
wrote: On Mon, 04 Apr 2005 23:12:53 -0400, DSK wrote: Michael wrote: Think "balanced" vs "unbalanced" rudders....power steering vs manual. The balance area of a rudder reduces the perceived load on the helm, but does *not* reduce the load on the rudder post. /// Fresh Breezes-- Doug King Hmmm...seems to me that the steering torque on a rudder can be reduced, zeroed or reversed - depending on the balance area fraction selected. The rule of thumb, I seem to recall is 25% area forward for minimal torque - more than that and the torque is reversed, giving unpleasant positive feedback effect. Sure, but the topic was rudder bearings. They don't get loade by torque, but by radial loads from lift generated by the rudder. Rodney Myrvaagnes NYC J36 Gjo/a "Nuke the gay whales for Jesus" -- anon T-shirt |
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#6
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On Tue, 05 Apr 2005 12:02:39 -0400, Rodney Myrvaagnes
wrote: On Tue, 05 Apr 2005 03:24:46 GMT, Brian Whatcott wrote: On Mon, 04 Apr 2005 23:12:53 -0400, DSK wrote: Michael wrote: Think "balanced" vs "unbalanced" rudders....power steering vs manual. The balance area of a rudder reduces the perceived load on the helm, but does *not* reduce the load on the rudder post. /// Fresh Breezes-- Doug King Hmmm...seems to me that the steering torque on a rudder can be reduced, zeroed or reversed - depending on the balance area fraction selected. The rule of thumb, I seem to recall is 25% area forward for minimal torque - more than that and the torque is reversed, giving unpleasant positive feedback effect. Sure, but the topic was rudder bearings. They don't get loade by torque, but by radial loads from lift generated by the rudder. Rodney Myrvaagnes NYC J36 Gjo/a Yes, you're right of course. And this was Doug's point, I think. Brian W Altus, OK |
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#7
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On Mon, 04 Apr 2005 23:12:53 -0400, DSK wrote:
(snip) Michael wrote: Think "balanced" vs "unbalanced" rudders....power steering vs manual. The balance area of a rudder reduces the perceived load on the helm, but does *not* reduce the load on the rudder post. I think it would be more accurate to say that the force by the helmsman requires less physical effort with a balanced rudder. I can not think of anything that would reduce the load on a rudder post.... I am not aware of any production boat that was built with the bearings you suggest. I though such beasts do exist for rudders.. Probably not in the 30' size range. Fancy racing boats have top-notch rudder post bearings, and of course bigger boats have to have bearings appropriate to the load... if they're well designed of course... It's a worthwhile upgrade to a boat that will spend a lot of time sailing hard on autopilot. Humm.... I think I would rather have a bushing, I dont think a bearing in a water environment would last or be as reliable as a bushing... A wild guess is that 80% of boat owners dont know how to do this or 80% of any other work that may be required to be done, yet they own boats. IMHO that's a wild overestimate. Most boat owners I know (mostly mid-size sailboats) know how to do a wide variety of technical things and all basic maintenance. The stuff that gets done by hired help is either really demanding & technical, perhaps requiring special tools... like testing injectors or timing injector pumps... or really tedious & awfule, like sanding off old bottom paint. Standing rigging has little to do with the designer In terms of it replacement, sure designers initially determine the original config. and I have yet to see anyone change that (from an original design aspect). I have. In a very few cases did it turn out to be a wise move. ... Very rarely would the design of the standing rigging be changed on a production boat. Depends on who is doing what. A a relatively common change is adding an inner stay for a staysail. Ya but thats not a mod like separating two shrouds from a single chain plate, or mounting the chain plate on the outboard of the hull, etc.... a inner stay isnt a mod of the existing rig but an addition to it What I had in mind is the excessively salty type who brags about "upgrading" his standing rigging to the next larger size, because it so macho to brag about sailing in high winds. The issue here is that 1- rigging is sized to the boat's righting moment regadless of wind strength and 2- heavier rigging will dregarde the boats performance and 3- because of the difficulty in getting the tensions correct, may actually weaken the overall rig & bring down the mast. Yep, Dave Martin. He stayed in Oriental, NC for quite a while. Some of what he did made good sense... putting on larger standing rigging did not. In fact (as I said) from an engineering standpoint it can be harmful. Where does all the added stress from this stronger rigging go? It doesn't disappear! Yes there are downsides to upgrading the standing rigging to a larger size, one increment in size would not make a difference Yes, it would. There would be a difference in weight aloft, in windage, in stress generated from the additional tension needed to keep that heavier gage rigging from shock loading, and in any event (as I said) the standing rigging loads are determined by the boat's righting moment. The strongest possible wind will not impose any more strain on it. However the heavier gage will require greater tension and will have less elasticity and will probably overstress the chainplates and will definitely place a greater compression load on the mast. I dont necessarly disagree with you but from all those who have upgraded one size I have never heard any issue as a result from the end user or a rigger.... I have never yet heard of anybody putting on a thicker mast because they want a tougher more seaworthy boat. In short, putting on heavier standing rig is good *only* if it was undersized originally. In any other possible case, it is detrimental to the boat's performance and seaworthiness. Period. .... But I do see the postive aspect of its use. I would rather replace it more often at that cost than figure the SS rigging will last as long as the rest of the boat. Get Sta-Loks. You'll never need to replace anything but the very inexpensive cones. Yes they are better than the Norseman ones from the test results I have read. As far as I am concerned a saildrive unit is essentially an outboard with more negatives. Like what? The newer saildrives are great. Less trouble, more efficient, and neater installation, than a conventional inboard.... you can put both the engine weight and the prop in more advantageous locations. For the lower unit the boat must be dry docked to service it, where a OB on a laz maybe pulled at any time. COST... Is a saildrive generally prefered over a conventional IB? I dont think so, why is that? Multihulls have saildrives or OB's I would rather have the OB's check out this excellent pictoral of a OB in a laz as well as general project boat: http://pearsonariel.org/discussion/s...9&page=1&pp=15 you should go through all 15 pages The advantages of an outboard are 1- cost 2- winter storage in your closet 3- service by removing it to the shop 4- maneuverability (*if* the installation is such that the helmsman can swivel it) Pretty much everything else about them is a negative. Fuel economy & heavy weather performance are terrible. Very true, but then risk of theivery or submergence or damage is higher; reliability is often lower too. Point for the lazerrete config..... Putting the OB in a lazarette might reduce the chance of theivery, but it increases the chance of flooding... those wells get a surge up in them at every wave, your engine could go under water 500 times and you wouldn't see it. Many of the also amplify noise, and choke the engine. They keep that traditional counter stern looking sweet, though. That's been my experience with a dozen or so boats equipped with outboards in wells. YMMV In my case, I have always bought bargain-basement boats for very cheap (ie within my budget) and fixed them up myself. But it's really sailing... both racing & cruising... with my family that I enjoy most. It's the means to an end. The economic advantage doesnt always outweight the practical downside, mileage will vary....Boat repair can be a hobby to a degree. And it also gives you a boat that you know all about, and can fix, and can rely on. Yes, if you have got the time and passion http://www.bumfuzzle.com/logs11-04.htm You may be interested in the issues with a 2 year old cat on a circumnaviation by novice sailors. http://www.bumfuzzle.com/ Much so called "wisdom" is perception also:}} "Genius is limited and stupidity is unlimited" That's an excellent quote. One of my favorites is "The trouble with the world is that the stupid are cocksure and the intelligent are full of doubt" --Bertrand Russell Fresh Breezes-- Doug King |
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#8
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The balance area of a rudder reduces the perceived load on the helm, but
does *not* reduce the load on the rudder post. Michael wrote: I think it would be more accurate to say that the force by the helmsman requires less physical effort with a balanced rudder. Yes, that's what I was trying to say. I can not think of anything that would reduce the load on a rudder post.... Going very slowly! I am not aware of any production boat that was built with the bearings you suggest. I though such beasts do exist for rudders.. Probably not in the 30' size range. Fancy racing boats have top-notch rudder post bearings, and of course bigger boats have to have bearings appropriate to the load... if they're well designed of course... It's a worthwhile upgrade to a boat that will spend a lot of time sailing hard on autopilot. Humm.... I think I would rather have a bushing, I dont think a bearing in a water environment would last or be as reliable as a bushing... ??? There's this new hi-tech miracle product called "grease." Of course it's assumed that the bearing will get some maintenance, and will eventually have to be replaced. In well-designed boats this is provided for. Actually modern miracle hi-tech stuff has made it very easy to re-work rudder post bearings, or bushings if you prefer. After all a bushing in this case is the same thing as a bearing. It's not even necessary to pull the rudder & post out, just polish & wax it then pour in the miracle goop. As far as I am concerned a saildrive unit is essentially an outboard with more negatives. Like what? The newer saildrives are great. Less trouble, more efficient, and neater installation, than a conventional inboard.... you can put both the engine weight and the prop in more advantageous locations. For the lower unit the boat must be dry docked to service it, So? That's true of any inboard. With a conventional drive you have a cutlass bearing which can't be serviced unless the boat is pulled. Again, it's assumed that these things are going to get proper attention during the life of the boat. ... where a OB on a laz maybe pulled at any time. COST... And if you get a trailerable boat, you can haul it out even cheaper, then take it home with you. Very inexpensive (if you already have a place to keep it, that is). Is a saildrive generally prefered over a conventional IB? I dont think so, why is that? Depends on who you're talking to. The saildrive has a lot of advantages but many people still don't like them. It's a matter of personal taste to some degree. check out this excellent pictoral of a OB in a laz as well as general project boat: http://pearsonariel.org/discussion/s...9&page=1&pp=15 I think this guy is making a few mistakes. For example, removing the shelves below the V-berth... those were almost certainly there as structural members. The cockpit drains look nice though. It's funny you should point to a Pearson Ariel as an example of how wonderful OB wells are. I sailed on one of these for years (back when they were much newer than they are now) and it is one of the boats that formed my current opinion (generally unfavorable) of OB wells. It's not the worst of the bunch, though. Thanks for the links, interesting reading & pictures. Fresh Breezes- Doug King |
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#9
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On Mon, 04 Apr 2005 23:12:53 -0400, DSK wrote:
snip As far as I am concerned a saildrive unit is essentially an outboard with more negatives. Like what? The newer saildrives are great. Less trouble, more efficient, and neater installation, than a conventional inboard.... you can put both the engine weight and the prop in more advantageous locations. The advantages of an outboard are 1- cost 2- winter storage in your closet 3- service by removing it to the shop 4- maneuverability (*if* the installation is such that the helmsman can swivel it) Saildrive issues link: http://www.cruisersforum.com/showthr... threadid=1666 |
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