Billy posted a link in the Venture section of this board, for macgregor parts...saw this part and its description.
Mac26X HDPE Hi-Perf. Centerboard $495.00
Click to enlarge
252613 Hi Performance hdpe centerboard for your Mac 26X. This is a direct replacement centerboard for the original fiberglass model, no modifications to your Mac are necessary. Improved low-drag performance airfoil shape, heavy duty attachment point for the uphaul line. If you've experienced problems with your centerboard cracking, splitting the trailing edge other issues, this centerboard is the solution. The board is weighted in the tip with 8lbs of lead to quickly sink, it is solid and will not fill with water like the original. Helps improve pointing ability and resists fouling even without bottom paint. Lifetime warranty.
Replacement center board
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Captain Steve
- Captain
- Posts: 722
- Joined: Fri Jan 02, 2004 9:40 am
- Sailboat: MacGregor 26X
- Location: Oxnard, CA "Wildest Dream" '98X Nissan 50
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Duane Dunn, Allegro
- Admiral
- Posts: 2459
- Joined: Fri Jan 02, 2004 6:41 pm
- Sailboat: MacGregor 26X
- Location: Bellevue, Wa '96 26x, Tohatsu 90 TLDI and Plug In Hybrid Electric drive
- Contact:
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waternwaves
- Admiral
- Posts: 1499
- Joined: Wed Oct 13, 2004 8:18 pm
- Location: X less in North Puget Sound -have to sail other boats for a while
hype
First of all, let me go on record as saying I 100% support everyone trying out new mods and marketing mac mods, I think the demand is out there, but let me also be the first to clamor for performance metrics.
and the wording claimed for the above HDPE CB discourages me.....
some of these are interesting "claims" may not be what they seem.
even tho they may be conflicting..
1) "Improved low-drag performance airfoil shape" vs. "Helps improve pointing ability " How is pointing ability improved... ?? more lift from the airfoil?? or the canting/gybing Which Moe so clearly illustrated is already going the wrong way on the X boat. What is the new foil profile? Is this improved pointing ability from greater lift of the CB, or imobilizing it in the centerboard trunk. Since HDPE is not as stiff as glass.... high lateral loads result in greater deformation of the CB, which leads to questons about slip, geometry of the foil etc... drag analysis for the simpler NACA shapes is out there for free on the web, .............that is something easily checked.....
Like several other people in the forum, I have looked at a socket arrangement for the top of the CB in the trunk to hold the CB still and limit the rotating of the CB underway....
2) heavy duty attachment point " vs This attachement point probably has more to do with the addtitional weight of a HDPE CB, and not something that provides additional strength to the CB trunk, which is what I would prefer,... I would rather have the bracket break on impact than a hole in the CB trunk....(especially since the hole in the latter gets me toesies wet....)
3) "is solid and will not fill with water like the original" since when is a CB filled with water a problem???
4) and most of all, the one thing that HDPE seems incredibly well suited for (when properly designed) (which is not even mentioned) is incredible impact and wear resistance, around all that wonderful Florida sharp stuff.(coral)
One of the items nicely addressed is "lifetime warranty" nice to see some warranty, Tho a Moneyback Guarantee is more preferable. My favorite detail "no modifications to your Mac are necessary" seems to be a feature most of us clamor for.
Well, I guess Caveat Emptor.
and the wording claimed for the above HDPE CB discourages me.....
some of these are interesting "claims" may not be what they seem.
even tho they may be conflicting..
1) "Improved low-drag performance airfoil shape" vs. "Helps improve pointing ability " How is pointing ability improved... ?? more lift from the airfoil?? or the canting/gybing Which Moe so clearly illustrated is already going the wrong way on the X boat. What is the new foil profile? Is this improved pointing ability from greater lift of the CB, or imobilizing it in the centerboard trunk. Since HDPE is not as stiff as glass.... high lateral loads result in greater deformation of the CB, which leads to questons about slip, geometry of the foil etc... drag analysis for the simpler NACA shapes is out there for free on the web, .............that is something easily checked.....
Like several other people in the forum, I have looked at a socket arrangement for the top of the CB in the trunk to hold the CB still and limit the rotating of the CB underway....
2) heavy duty attachment point " vs This attachement point probably has more to do with the addtitional weight of a HDPE CB, and not something that provides additional strength to the CB trunk, which is what I would prefer,... I would rather have the bracket break on impact than a hole in the CB trunk....(especially since the hole in the latter gets me toesies wet....)
3) "is solid and will not fill with water like the original" since when is a CB filled with water a problem???
4) and most of all, the one thing that HDPE seems incredibly well suited for (when properly designed) (which is not even mentioned) is incredible impact and wear resistance, around all that wonderful Florida sharp stuff.(coral)
One of the items nicely addressed is "lifetime warranty" nice to see some warranty, Tho a Moneyback Guarantee is more preferable. My favorite detail "no modifications to your Mac are necessary" seems to be a feature most of us clamor for.
Well, I guess Caveat Emptor.
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Murv Barry
- Deckhand
- Posts: 26
- Joined: Sun Apr 11, 2004 5:43 pm
Reinforced centerboard
The hole in my centerboard was ripped out as a result of a grounding.
Fortunately the line secured it till I could get the boat on the trailer. I rebuilt the fractured area including a new ss sleeve. On each side I placed 4" X 8" X 3/16" SS plates which I bolted together. The nuts for the 6 bolts are welded on the inside of the stb'd plate. The flathead bolts are countersunk on the port plate. At the same time, by coincidence, I made mahogany rudders. The ruddders are about 30% larger than the originals. Same up and down length but the top of the leading edge was increased so now the rudder extends under the boat. The leading edge then trails back to the bottom of the original rudder. I haven't had an opportunity to race against anyone to get a comparison with these two mods but again today I was able to sail at 30% heel in 15+ kts of wind without rounding up. Not normal sailing but did it as a test. The boat is very well balanced and just feels so much stronger. When gusts hit, the heel increased but it held it's course without touching the wheel. Mast is vertical, the centerboard is now true and the rudders are larger. So far I am pleased.
Good sailing, Murv
Fortunately the line secured it till I could get the boat on the trailer. I rebuilt the fractured area including a new ss sleeve. On each side I placed 4" X 8" X 3/16" SS plates which I bolted together. The nuts for the 6 bolts are welded on the inside of the stb'd plate. The flathead bolts are countersunk on the port plate. At the same time, by coincidence, I made mahogany rudders. The ruddders are about 30% larger than the originals. Same up and down length but the top of the leading edge was increased so now the rudder extends under the boat. The leading edge then trails back to the bottom of the original rudder. I haven't had an opportunity to race against anyone to get a comparison with these two mods but again today I was able to sail at 30% heel in 15+ kts of wind without rounding up. Not normal sailing but did it as a test. The boat is very well balanced and just feels so much stronger. When gusts hit, the heel increased but it held it's course without touching the wheel. Mast is vertical, the centerboard is now true and the rudders are larger. So far I am pleased.
Good sailing, Murv
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Don T
- Admiral
- Posts: 1084
- Joined: Fri Jan 02, 2004 7:13 pm
- Sailboat: MacGregor 26X
- Location: 95 2600 "SS OTTER" - Portland OR - Tohatsu 50 - Hull#64 (May 95)
Hello:
My quiet center board mod also keeps it from gybing. Since it has been this way for 8 years I can't really give a comparison on pointing ability.
http://www.macgregorsailors.com/cgi-bin ... record=390
My quiet center board mod also keeps it from gybing. Since it has been this way for 8 years I can't really give a comparison on pointing ability.
http://www.macgregorsailors.com/cgi-bin ... record=390
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Frank C
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Frank C
Re: Reinforced centerboard
Hmmmm - food for thought. This raises the question of the trade-off between high-aspect foils (fin-like) versus more traditional shapes.Murv Barry wrote: . . The ruddders are about 30% larger than the originals. Same up and down length but the top of the leading edge was increased so now the rudder extends under the boat.
. . . The boat is very well balanced and just feels so much stronger. When gusts hit, the heel increased but it held it's course without touching the wheel. Mast is vertical, the centerboard is now true and the rudders are larger. So far I am pleased.
Not sure of this, but I guess the most obvious contrast is that higher aspect ratio should give greater lift with less drag? Sounds like greater lift comes at a price of more finicky handling of a fin-foil (balancing along a razor edge) with less robust directional control?
I'd like to try it Murv's way, which has also been a common mod for the Mac classic rudders. Adding rudder surface forward of the rudder stock (pivot pin) also reduces the turning effort, ergo reducing the strain on the steering gear.
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Dimitri-2000X-Tampa
- Admiral
- Posts: 2043
- Joined: Fri Jan 02, 2004 5:36 am
- Sailboat: MacGregor 26X
- Location: Tampa, Florida 2000 Mercury BigFoot 50HP 4-Stroke on 26X hull# 3575.B000
You're only going to get more lift with less drag...at higher speeds...with the high aspect ratio foils. It is the same with airplane wings. Consequently, you have a much higher stall speed...which can be problematic on a sailboat going too slowly.
The best way to do it would be to have multiple rudders like you have multiple sails. Use the big (low aspect ratio) rudders at lower speeds, and the smaller (high aspect ratio) rudders at higher speeds (like when you have your Mac sailing at 17mph
).
Talking about speed, nah...I'll start a new topic for that one.
The best way to do it would be to have multiple rudders like you have multiple sails. Use the big (low aspect ratio) rudders at lower speeds, and the smaller (high aspect ratio) rudders at higher speeds (like when you have your Mac sailing at 17mph
).Talking about speed, nah...I'll start a new topic for that one.
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waternwaves
- Admiral
- Posts: 1499
- Joined: Wed Oct 13, 2004 8:18 pm
- Location: X less in North Puget Sound -have to sail other boats for a while
frank.....er,... well ah,....
"Adding rudder surface forward of the rudder stock (pivot pin) also reduces the turning effort, ergo reducing the strain on the steering gear."
I'll go back to the older discussion here....
increasing area of the rudders increases the forces on the brackets, pins, and hull mount.. I think I'll stick with the steering gear being weaker than the rudder mounts.(I can fix the steering gear while inside the boat) ... a broken rudder mount on the boat causes much greater problem than broken steering gear. This is one mod that DOES not seem to be a good idea unless you have increased the internal support for the rudder brackets and increased mounting hardware size, to handle increases in rudder sizes.
and Dimitri,..... Thanks buddy..... thanks a lot.....
Like I dont have enough trouble designing a variable size CB and sealable centerboard trunk already..
ya just gotta keep throwing out those darn ideas.....
But rudders that raise and lower automaticly and change wetted area as a function of speed...., hmmmmmmm
"Adding rudder surface forward of the rudder stock (pivot pin) also reduces the turning effort, ergo reducing the strain on the steering gear."
I'll go back to the older discussion here....
increasing area of the rudders increases the forces on the brackets, pins, and hull mount.. I think I'll stick with the steering gear being weaker than the rudder mounts.(I can fix the steering gear while inside the boat) ... a broken rudder mount on the boat causes much greater problem than broken steering gear. This is one mod that DOES not seem to be a good idea unless you have increased the internal support for the rudder brackets and increased mounting hardware size, to handle increases in rudder sizes.
and Dimitri,..... Thanks buddy..... thanks a lot.....
Like I dont have enough trouble designing a variable size CB and sealable centerboard trunk already..
ya just gotta keep throwing out those darn ideas.....
But rudders that raise and lower automaticly and change wetted area as a function of speed...., hmmmmmmm
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Randy Smith
- First Officer
- Posts: 254
- Joined: Mon Oct 11, 2004 11:31 am
- Location: "Breezy" 26X Boardman,Or
Once again, waternwaves, Man of common sense!
my title says it all....your first post on this thread really stated well this issue of modifications.....too many times modifications may lead to other problems or considerations not factored in....the basic boat is awesome, and changes to integeral designs may not be as expected...changing the boat needs more than sales pitch and speculation.....I appreciate your thoughtful posts....Randy 
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Frank C
Hmmmm - even more food for thought, Darren. If I've read you correctly, the basic boat delivers woefully less than awesome performance, right? Even granting that increased rudder surface would increase loads on the brackets, I'm glad to see you're not suggesting that's a reason to do nothing!waternwaves wrote:frank.....
increasing area of the rudders increases the forces on the brackets, pins, and hull mount ... a broken rudder mount on the boat causes much greater problem than broken steering gear. This is one mod that DOES not seem to be a good idea unless you have increased the internal support for the rudder brackets and increased mounting hardware size, to handle increases in rudder sizes.
- 1. Even with substantive adjustments for sailplan control (mast rake, improved backstay, outhaul & vang, even a traveler in Murv's case) the boat is inordinately prone to rounding up in heavier winds.
2. Rudder performance is clearly sub-optimal even at maximum sailing speeds (~7 knots, where the aspect ratio works best), therefore eligible for impovement efforts.
3. The stainless rudder brackets (since '99) are much improved, less prone to failure. Therefore, IMO, a rudder improvement certainly merits at least a little study.
4. Though Murv's rudder mod is the first I've ever read of, the rudders seem a natural target for tweaking.
WADR, if Murv's already done it, I have two observations. First, I don't doubt the transom or rudder brackets are up to the task, and second, I bet anyone who avoids it is destined to trail the race with him.
Just another opinion . . .
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waternwaves
- Admiral
- Posts: 1499
- Joined: Wed Oct 13, 2004 8:18 pm
- Location: X less in North Puget Sound -have to sail other boats for a while
modification clarification
O Frank..
You know better that I would never dream of telling people not to modify macslolthat would definitely be a pot calling the kettle black.
However I do have some experience breaking parts in heavy seas.sometimes repeatedly, for example torn sails and broken steering. Slapping the mast around, rigging for staysail, stormjib or stunsail, converting to a cutter rig etc As I keep increasing the replacing of parts.
I am very particular on failure modes I do not like hanging off the transom....lol
Now, not to belittle the racing contingent I personally have no interest in racing sailboats.I find it similar to observing folks argue religion, choosing paint colors (purple is faster), speed mountain climbing, arguing Ford vs. Chevy vs. Toyota etc..While I am sure there is camaraderie afterwards, and many new techniques and improvements stem from those that race sailboats.. but not all, Fine for others just not for meThere are uncontrolled variables..throughout any racebut I will try and stick to testing performance of items with repeatable metrics. ( I already know that I am not the best sailor in the world, why prove it every week, ?? or try to get lucky??I dont have enough time or money to sail enough as it is) .. the racing focus is not my focus. So you can understand why my focus is on ruggedness, not necessarily that last fraction of a knot of speed.. Which is why I my interest is on modifications on making the boat stronger and perform better, not just speed. Same reason I am willing to work on 90 hp E-tec mods on my boat seems suited to the intrinsic strength of the boat with the least modification I dont need 37 mph. but I do need 25 mph.
This forum focuses on the macss not the racing therefore I note most people are into the equipment aspect not are not as heavily not the racing, winning, competition elements. Racers seem to have the predilection against macs for the most part anyway...
So. I also have several items from pulpit to rudders that I wish to improve. I would like to modify my rudder pivot plane closer to the cp of the rudders, giving lighter trim, but the existing mounts and brackets do not have the required strength for an extension. So since I am modifying the transom anyway, that will be picked up in that mod for the stronger outboard.
I have looked at the stainless brackets (While designing my own) .. while better than the aluminum , I dislike the mounts still, . So there is still room for reinforcement and improvement. and this forum has noted breakage of both kinds of brackets.
And I am all for improving things..!!!! just not singly and I always prefer to discuss the tradeoffs with any change as well as identify any additional reinforcements required to make any change acceptable. So I am glad you noted that I am not against change..; I just think it is important to identify the caveats and tradeoffs.
So I commend those wining and trying racers on their performance and changes. But I will continue with toughening up the boatlol And since I have not seen any of Murvs changes to the mounts I will not comment on that. (suffice to say that information about mounting bracket and post improvements were not mentioned with the rudder changes in the quote, and I look forward to finding out more.
Btw, And some of us trail very safely and comfortably singlehandedly..there is plenty of joy and relief weathering/surviving the weather that rolls in from the north pacific for me, greater than racing.
You know better that I would never dream of telling people not to modify macslolthat would definitely be a pot calling the kettle black.
However I do have some experience breaking parts in heavy seas.sometimes repeatedly, for example torn sails and broken steering. Slapping the mast around, rigging for staysail, stormjib or stunsail, converting to a cutter rig etc As I keep increasing the replacing of parts.
I am very particular on failure modes I do not like hanging off the transom....lol
Now, not to belittle the racing contingent I personally have no interest in racing sailboats.I find it similar to observing folks argue religion, choosing paint colors (purple is faster), speed mountain climbing, arguing Ford vs. Chevy vs. Toyota etc..While I am sure there is camaraderie afterwards, and many new techniques and improvements stem from those that race sailboats.. but not all, Fine for others just not for meThere are uncontrolled variables..throughout any racebut I will try and stick to testing performance of items with repeatable metrics. ( I already know that I am not the best sailor in the world, why prove it every week, ?? or try to get lucky??I dont have enough time or money to sail enough as it is) .. the racing focus is not my focus. So you can understand why my focus is on ruggedness, not necessarily that last fraction of a knot of speed.. Which is why I my interest is on modifications on making the boat stronger and perform better, not just speed. Same reason I am willing to work on 90 hp E-tec mods on my boat seems suited to the intrinsic strength of the boat with the least modification I dont need 37 mph. but I do need 25 mph.
This forum focuses on the macss not the racing therefore I note most people are into the equipment aspect not are not as heavily not the racing, winning, competition elements. Racers seem to have the predilection against macs for the most part anyway...
So. I also have several items from pulpit to rudders that I wish to improve. I would like to modify my rudder pivot plane closer to the cp of the rudders, giving lighter trim, but the existing mounts and brackets do not have the required strength for an extension. So since I am modifying the transom anyway, that will be picked up in that mod for the stronger outboard.
I have looked at the stainless brackets (While designing my own) .. while better than the aluminum , I dislike the mounts still, . So there is still room for reinforcement and improvement. and this forum has noted breakage of both kinds of brackets.
And I am all for improving things..!!!! just not singly and I always prefer to discuss the tradeoffs with any change as well as identify any additional reinforcements required to make any change acceptable. So I am glad you noted that I am not against change..; I just think it is important to identify the caveats and tradeoffs.
So I commend those wining and trying racers on their performance and changes. But I will continue with toughening up the boatlol And since I have not seen any of Murvs changes to the mounts I will not comment on that. (suffice to say that information about mounting bracket and post improvements were not mentioned with the rudder changes in the quote, and I look forward to finding out more.
Btw, And some of us trail very safely and comfortably singlehandedly..there is plenty of joy and relief weathering/surviving the weather that rolls in from the north pacific for me, greater than racing.
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Randy Smith
- First Officer
- Posts: 254
- Joined: Mon Oct 11, 2004 11:31 am
- Location: "Breezy" 26X Boardman,Or
mods
waternwaves:
again, I tip my cap to you as you said perfectly the way I feel about my Mac and modifications to it. Who wrote that song with the line, "...one thing leads to another...."? That is why I try and be careful with mods, money, time, further breakage, and time with a broken boat...make me choose carefully what I do to Breezy. I want the old girl ready on Saturday and Sunday each week.
Those more adventurous than I, keep up the good work...just understand that for a new swing keel at 495$(blue or white), I can buy "alota" gas, beer, picinic baskets and many smaller mods which I will enjoy more.
And hey, not trying to insult or inflame an argument, just laying down some Oregonian frankness. Again, I do respect the people on this site, doesn't mean we have to agree....I love to check daily and see what is going on and if I can learn, as well as contribute. Randy
again, I tip my cap to you as you said perfectly the way I feel about my Mac and modifications to it. Who wrote that song with the line, "...one thing leads to another...."? That is why I try and be careful with mods, money, time, further breakage, and time with a broken boat...make me choose carefully what I do to Breezy. I want the old girl ready on Saturday and Sunday each week.
Those more adventurous than I, keep up the good work...just understand that for a new swing keel at 495$(blue or white), I can buy "alota" gas, beer, picinic baskets and many smaller mods which I will enjoy more.
And hey, not trying to insult or inflame an argument, just laying down some Oregonian frankness. Again, I do respect the people on this site, doesn't mean we have to agree....I love to check daily and see what is going on and if I can learn, as well as contribute.
Randy