[Public-List] Mast Rake

Sun Feb 14 07:59:33 PST 2016

Hi all, 
1) I have tuned rigs on several boats using the cockpit seats as the reference point.  I place a level on the seats and then load the boat fore and aft to level. Getting off the boat after each trial.  This is a bit easier on the hard. Once level, I rake the mast back so that an adjustable wrench hanging from the main halyard is 10" to 12" aft of the mast sail track on an Alberg 30 just above the boom. 
The fore stay and aft stay then get their preliminary tension adjustments. I then check the port/starboard alignment by adjusting the cap shrouds. The lowers come after that. Then the final tensioning. 

2) This is what I consider my "origin" of rig adjustment. You can always go back to the seat level "origin". That is always the same. While not absolutely perfect it is accurate enough to begin with every time the rig is tuned. 

3) An aside; generally, I prefer a slight rake. I believe it improves pointing ability, especially in a dinghy.  Down wind performance is affected negatively, but as a racer, think about it, 2/3rds of the "time" on the race course you are going upwind and 1/3rd downwind. I would rather error toward the up wind performance side of things. 

4) After number 2) above you measure the back stay length by hauling a tape measure up until it stops at the mast head sheave and use a known reference point on the aft stay chain plate. Use the same tape and references so that you can easily duplicate anytime.  Then "sail the boat".  Using different sail combinations under different wind and sea conditions you look for that "Golden Mean".  If you can't trim out excessive weather helm then go back and make some rake adjustments using the back stay measurement. 
I have been using this procedure for the past twenty years with consistent and good results. If followed, it is easy to get back "close" to your satisfying rig tune every time you re-step your mast. Again, a sea trial provides you with the final answer on rig tune. 

Hope this is helpful, 
Michael #133 
----- Original Message -----

From: "Lawrence Morris via Public-List" <public-list at lists.alberg30.org> 
To: "John Birch" <Sunstone at cogeco.ca>, "Alberg 30 Public List -- open to all" <public-list at lists.alberg30.org> 
Sent: Sunday, February 14, 2016 10:22:12 AM 
Subject: Re: [Public-List] Mast Rake 

The plumb bob is a reference.  Just be careful that big uncle frank is not standing in the cockpit at the time or on the bow. 

The best method is to measure the back stay with the measuring tape hoisted with main halyard.  I don't remember the measurement, but I am sure it is on the website somewhere.  George, help!!!! 

Larry 

Sent from my iPad 

> On Feb 14, 2016, at 10:01 AM, John Birch via Public-List <public-list at lists.alberg30.org> wrote: 
> 
> 90 degrees to the water. Hang the loose main halyard down, sometimes a light weight is required to get it to act like a plumb bob. It should not be hanging aft of the mast. If it is, that is rake. The more it hangs aft of the mast, the more rake. The more rake, the more load being put on the aft part of the mast step which is not particularly well supported as it is not over the mast beam. 
> 
> Cheers, 
> 
> JB 
> 
> Re: 
> 
> I remember our A-30 had this problem (KC-544) until we started tuning our rig like the Chesapeake racers. Mast vertical, no rake, or virtually no rake. That took the loading off the deck at the back of the mast foot, which is not supported particularly well by the Aluminium deck beam, putting most of the downward force under the front of the mast step directly over the deck beam. 
> 
> Problem solved. Our decks were dry with no delam. It was a simple compression issue on the back of the step. 
> 
> Hope that is a help. 
> 
> Cheers from Western Lake Ontario, y'all 
> 
> JB 
> 
> 
> ----- Original Message ----- From: "Anders Bro via Public-List" <public-list at lists.alberg30.org> 
> To: "Greg Bover" <gregbover at cbfisk.com>; "Alberg 30 Public List -- open to all" <public-list at lists.alberg30.org> 
> Sent: Sunday, February 14, 2016 8:46 AM 
> Subject: Re: [Public-List] Mast Rake 
> 
> 
>> Now why didn't I think of that? (I guess I just don't think?) 
>> Thanks, 
>> Anders 
>> 
>> Sent from my iPhone 
>> 
>>> On Feb 14, 2016, at 8:31 AM, Greg Bover via Public-List <public-list at lists.alberg30.org> wrote: 
>>> 
>>> Use your main halyard as a plumb bob. 
>>> 
>>>> I was wondering if someone would clarify for me what "vertical" means on a 
>>> sailboat which doesn't have any reference lines (except perhaps the vague 
>>> plane of the waterline). If you are setting the mast rake wrt the waterline, 
>>> how do you assess this angle (since it is difficult to see the waterline 
>>> from the deck where a person is making the adjustments). Maybe Instead you 
>>> establish this angle wrt the lowers? (splitting the angle?) Or maybe on a 
>>> calm day afar with a level while the boat is afloat? Or maybe just trial and 
>>> error??? 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> Greg Bover 
>>> A-30 #114 
>>> PENSIVE FLYER 
>>> Gloucester 
>>> 
>>> 
>>> 
>>> 
>>> --- 
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