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Re: Weak links in the macgregor

Posted: Thu Jan 25, 2018 4:34 pm
by Tomfoolery
whgoffrn wrote:And as far as weather helm.... I thought that the pressure applied to the boat was in between the mast and where the main sheet is connected .... being the only two connection points the main has ..... adding a 3rd reef not only brings the main down but in closer to the mast ........ unless I'm misunderstood in the physics of this pressure and the location pushes or pulls the boat I thought moving the farthest aft attachment point up moves this force up a few feet also reducing the weather helm which is caused by pressure applied to far aft and past the point of center pivot of the boat
Moving the center of pressure down and forward certainly should reduce weather helm, in broad terms. For for a given sail size (CoP in the same place), moving the main sheet only rearranges the forces and moments within the system, but doesn't change where that CoP is within the system.

Sure, the main sheet (all else being equal), when terminated closer to the mast, exerts it force vector closer to the mast, but it also unloads the forces at the boom/mast connection. If you have a 10 ft boom, pinned at the mast with the main sheet at the opposite end, and you pushed exactly the middle of the boom, horizontally (only) perpendicular to the boom with some force, the boom end and the main sheet end would both be carrying the same horizontal component (along with some vertical component, of course).

Move the main sheet to the middle of the boom and push again, all the horizontal force would be taken by the main sheet, which is closer to the boom, but the boom connection would react exactly nothing. So the horizontal component, though closer to the mast, would also be larger, and the main sheet system would be taking a lot more load (higher tension - actually double in this example). And you'd end up not changing anything other than what the boom, mast, main sheet, and standing rigging handle, but the location of the CoP to the CoLR wouldn't change.

I'd have to draw sketches to illustrate it as it's hard to describe.

Re: Weak links in the macgregor

Posted: Thu Jan 25, 2018 4:47 pm
by whgoffrn
https://youtu.be/0UlLHiKF6to

Is the drogue I have and I had fiorentino go over the specs of a macgregor in regards to weight size freeboard winches attachment points to try to find a perfect size drogue that could work for our boats in the event of rudder failure....naturaly our boats use the smallest size they have but he assured me it would work .... if you skip to around 27 mins you can see how they use it for steering

Re: Weak links in the macgregor

Posted: Thu Jan 25, 2018 4:55 pm
by whgoffrn
And yes i can see mentally see how that would play out and be a pointless effort on moving the main sheet attachment.....if the boom was 10 feet longer and attached to the very stern of the boat while indeed the force is moved back it's much less force .....and vice versa move the attachment point up its not as far aft but the force goes up....so yeah I get it now..... I haven't had it out yet with the 3rd reef main yet but that should help some though as the entire sail area now is lower and closer to the mast bringing that center closer to mid pivot point ...also heeling the boat less should help

Re: Weak links in the macgregor

Posted: Thu Jan 25, 2018 9:59 pm
by kadet
whgoffrn wrote:https://youtu.be/0UlLHiKF6to

Is the drogue I have and I had fiorentino go over the specs of a macgregor in regards to weight size freeboard winches attachment points to try to find a perfect size drogue that could work for our boats in the event of rudder failure....naturaly our boats use the smallest size they have but he assured me it would work .... if you skip to around 27 mins you can see how they use it for steering
Our boats are light, keeless, squirrely and not sailed day after day in trade winds. I doubt effective steering could be achieved with a drogue. But I have been wrong before so am looking forward to your report on how it goes when you test it. 8)

Re: Weak links in the macgregor

Posted: Fri Jan 26, 2018 11:29 am
by Ixneigh
If even one rudder goes, you can hang up trying to sail the M model. She might certainly drift down wind in a crooked manner and be VERY uncomfortable. But so far as sailing like to be somewhere. No. Not with a drogue. Maybe a jury rudder that done well enough to allow the boat to reach decent speed. Now those brackets look pretty gimpy to me but apparently they hold up. Such that bwy refused to help me make stronger ones. But if I bend those suckers on a Bahamas trip you can be sure I will redo them so it won't happen again. 3/8 plate ought to do it.

Yes I know the M sails with one rudder in ideal conditions
Ix

Re: Weak links in the macgregor

Posted: Fri Jan 26, 2018 2:32 pm
by whgoffrn
Well I hope this drogue wasn't a waste of cash cause it was quite expensive at $600ish ....were going back to islamorada in March so I will test it out then.... I will attempt to motor and also sail with it and use it to steer and report back

Re: Weak links in the macgregor

Posted: Fri Jan 26, 2018 3:07 pm
by NiceAft
BOAT wrote:I looked up the main cause of shipwreck and after holes in the hull it seems to be "loss of steering" - There seems to be a million ways for it to happen, one story was about getting turtled in a storm and breaking rudders - a lot of stories about breaking rudders or bent rudder shafts after collision or grounding or hitting objects - I guess you can carry spare sails and fashion all kinds of jury rigs to get underway but without a rudder it seems to be a moot point. (By the way "moot" is the Hebrew word for DEAD) Granted most of the rudder failures I saw in the stats were big boats and cargo ships - military and so forth, - but if the rudders really are a "weak Link" it might be a good idea to address that considering the statistics.

My option would be to fashion a rudder that can attach to the outboard in a time of need. The outboard could be a great rudder if everything else is busted - it would just be better if there was a way to mount a board on the OB so it would be more effective as a rudder. It's a cheap insurance policy for rudder failure that should be easy to store on board. You could also store one spare stock rudder in case one breaks.

What about the dagger board? any chance of those getting broken off or lost? (I never sailed the gulf but I hear about shallow reefs and so forth).
BOAT,

As usual, your experience is valuable, but you did make a mistake. The Hebrew for "dead" is not "moot"
Image

It is pronounced like another nautical term, MATE :D
Image

You are close though. Moot, means "to die"
Image

There is a difference. Not much, but different. Maybe the point is moot :wink: :D

Re: Weak links in the macgregor

Posted: Fri Jan 26, 2018 3:20 pm
by BOAT
What is "he died" ?

Re: Weak links in the macgregor

Posted: Fri Jan 26, 2018 4:39 pm
by NiceAft
Brother, you’re really testing me now. :o

Re: Weak links in the macgregor

Posted: Fri Jan 26, 2018 4:47 pm
by BOAT
My confusion I think is the pronunciation of the original Hebrew verses the way people in Israel talk today - I think that's where I'm getting messed up - today I hear people there say mute! or "moot" - but I may be just listening to too many old people. Not sure how a younger person says it. So in the old Hebrew it's "mate"? or "mete"?

Re: Weak links in the macgregor

Posted: Fri Jan 26, 2018 4:55 pm
by NiceAft
He died is phonetically pronounced "who mate."

We are off topic now, but I will answer to the best of my ability.

In Israel they speak Sephardi, as apposed to Ashkenazi. Their pronunciations are different in the vowels of "Ah" and "Aw". I don't see this affecting what these words are.

I won't proceed any farther with this because we are far off topic. That is my fault for pointing out a small error.

I apologize to the Mac site.

Re: Weak links in the macgregor

Posted: Fri Jan 26, 2018 5:43 pm
by Bill at BOATS 4 SAIL
By far, I think the weakest link in the MacGregor, is the way the water from the motor well goes inside the boat and then out thru a thru-hull.
I had gotten a new Mac in, it had rained some, I went inside and there was water on the floor. So, I started bailing the water into the cockpit, and then realized the water level was not going down, as the water was coming right into the boat again thru the motor well. The tubing was not caulked correctly, so I did that.
What I've done on both my Mac 19 and 26 is plug the hole in the motor well so water can't enter the boat that way, and drilled a drain hole thru the transom so that water in the motor well can get out that way.
With some of the Macs well into their teens, and older, I think everyone should check the tubing that goes into the aft berth from the motor well.
I seriously suggest everyone plug the hole in the motor well.
Bill at BOATS 4 SAIL :mac19: :macx:

Re: Weak links in the macgregor

Posted: Fri Jan 26, 2018 8:00 pm
by whgoffrn
You may have just solved another problem I've had with water getting in my boat from an unknown location .... I've sawed my hatch door in half to make it easier to store and I assumed rain was leaking in through the line where I sawed it in half and they meet sometimes when it rains there's a foot of water other times there's nothing there just as sometimes leaves or debris plug the hole ....hmmmmm will have to investigate that further

Re: Weak links in the macgregor

Posted: Sat Jan 27, 2018 9:58 am
by whgoffrn
I can't help but wonder if I'm worrying about the rudder design or weakness too much ... Sure to be labeled a traitor I've had my eye on a corsair f27 for a bit and wonder if it's worth the extra $$$ ..... I feel in every way experienced enough and prepared enough for a 2 month trip to the exumas and my desire to go to the exumas is more than a desire now and borders on an obsession that i feel i must do at some point before I get cancer or life throws me some curveball preventing me from ever going but I worry about the boat not being up to the task.... I've now gotten to where I aim for squalls and storms to give me more practice and honestly the boat has never scared me too much besides the occasional round up and stuff crashing down below
I have no desires to go farther than thunderball grotto ....a corsair is a MUCH more proven offshore boat that can be sailed to Hawaii Bermuda and long ocean passages and still trailered and still floats shallow... but at the expense of 20k dollars more than I have in my macgregor ..... So being a tightwad by nature I can't help wonder if it would be 20 grand spent that wasn't necessary and if I overexaggerate in my head the weaknesses of the platform I currently have ....any info would be appreciated

Re: Weak links in the macgregor

Posted: Sat Jan 27, 2018 10:55 am
by NiceAft
For starters, I have to state that I have never taken the trip you desire, or any other trip of that duration. I have though, for many years, been reading the posts of those who have used their :macm: :macx: To go to far off places. The overwhelming consensus of those who have, is that the Mac is built much tougher than given credit for.

Jaime Alonzo sails his from Puerto Rico to BVI, regularly.

The weak points in that sort of sailing (in my view) are the rudders.

You obliviously are taking this seriously, and doing your due diligence.

Here is a You Tube video by cruisers who did the Exuma’s

https://youtu.be/WH0MeDHN-qQ

Ray