Page 1 of 2

centreboard adjustment as part of normal sailing

Posted: Fri Jul 15, 2011 11:08 am
by DaveC426913
I was just reading through the X manual. It suggests raising the cb 50% when on a beam reach, and 100% when sailing downwind.

1] Anyone do this by habit?
2] Is it even possible? I can barely move my cb when under sail.

Re: centreboard adjustment as part of normal sailing

Posted: Fri Jul 15, 2011 12:02 pm
by Chinook
I regularly follow that proceedure, and it seems to help. As far as pressure on the centerboard goes, by turning the wheel back and forth a bit, I am able to relieve pressure enough to pull the board up. Letting it down further can be another matter. Sometimes I just have to let the required amount of centerboard line out and wait a bit until the board drops.

Re: centreboard adjustment as part of normal sailing

Posted: Fri Jul 15, 2011 1:41 pm
by robbarnes1965
Yes and yes.

I sail on a lake that has a lot of shallow spots so I even do it on the fly when sailing close hauled and drop it back as soon as I am deeper.

I rigged a block like this one : http://www.macgregorsailors.com/modt/index.php?view=967
The line leading back has one end tied to the cleat with a bowline and the other is cleated just like you would normally.

Other boaters not familiar with the retractable dagger of the Mac are always yelling out in a panic at us when they see us racing through the shallows :) Don't forget to uncleat your rudders too when doing this...

Re: centreboard adjustment as part of normal sailing

Posted: Fri Jul 15, 2011 1:59 pm
by DaveC426913
Chinook wrote:I regularly follow that proceedure, and it seems to help. As far as pressure on the centerboard goes, by turning the wheel back and forth a bit, I am able to relieve pressure enough to pull the board up. Letting it down further can be another matter. Sometimes I just have to let the required amount of centerboard line out and wait a bit until the board drops.
Yeah. Familiar with that routine.

What exactly does it help? Speed?

Re: centreboard adjustment as part of normal sailing

Posted: Fri Jul 15, 2011 2:00 pm
by DaveC426913
robbarnes1965 wrote: I rigged a block like this one : http://www.macgregorsailors.com/modt/index.php?view=967
The line leading back has one end tied to the cleat with a bowline and the other is cleated just like you would normally.
Cool. 2:1. I like it.

Re: centreboard adjustment as part of normal sailing

Posted: Fri Jul 15, 2011 4:38 pm
by opie
This mod helps also to lessen friction:
Image

Re: centreboard adjustment as part of normal sailing

Posted: Fri Jul 15, 2011 5:23 pm
by c130king
I also did the 2:1 mod on the DB line...works great. Also have the same on rudders.

Jim

Re: centreboard adjustment as part of normal sailing

Posted: Fri Jul 15, 2011 6:16 pm
by hoaglandr
I also did the 2:1 mod on the DB line...works great. Also have the same on rudders.
Ditto. Now the admiral can raise the centerboard while I pull up the rudders. Much easier!

Russell

Re: centreboard adjustment as part of normal sailing

Posted: Fri Jul 15, 2011 6:31 pm
by Chinook
DaveC426913 wrote:What exactly does it help? Speed?
I can't quantify specific speed improvement. My guess is it might add a tenth or two of a knot on a reach, and maybe as much going downwind. It stands to reason that, while running with the wind, the centerboard in down position isn't helping a bit, and simply adds drag, kind of like sailing with the motor not tilted up.

Re: centreboard adjustment as part of normal sailing

Posted: Fri Jul 15, 2011 8:43 pm
by DaveC426913
c130king wrote:I also did the 2:1 mod on the DB line...works great. Also have the same on rudders.

Jim
Rudders! Huh! My rudders are almost impossible to lift. They're totally waterlogged. I've love to see how you rigged them.

Re: centreboard adjustment as part of normal sailing

Posted: Sat Jul 16, 2011 2:44 am
by Catigale
On the :macx: , moving the cb also changes the centre of lateral resistance which affect weather/lee helm.

Re: centreboard adjustment as part of normal sailing

Posted: Sat Jul 16, 2011 7:06 am
by bscott
Cat X 2
I regularly sail with my CB line pulled up 6-8" with a definate decrease in weather helm. Reduced weather helm reduces pressure and drag on the rudders = slight speed advantage. It further reduces rudder wear. Do not eliminate WH entirely as WH will come in handy if you fall over board.

The winch comes in handy for raising the board but I try not to use it because it really strains the line attachment.

Bob

Re: centreboard adjustment as part of normal sailing

Posted: Sat Jul 16, 2011 12:45 pm
by Capt Capsize
I use a 3 to 1 on the centerboard to adjust the centerboard and it is particularly useful when sailing under main sail only. Pull it about 1/3 the way up to balance the helm, otherwise it really wants to round up. When lowering I also I shift my weight side to side to allow the board to drop. Plus added a 2 to 1 on each rudder. I guess I am just lazy. I leave the centerboard part way down while I motor on the trailer, and give it a pull as the bow clears the goal posts. Out here in the wild west, docks on each side of the ramp are unheard of. :x and you have to drive it on.

Re: centreboard adjustment as part of normal sailing

Posted: Sat Jul 16, 2011 1:08 pm
by vizwhiz
I'm glad there's a post about this - my S has a swing-keel like the :macx: boats do (sure wish my S had a pretty icon like them too) :wink:
On the X, is the CB adjusted from below like the S, or is the line led above-deck like the DB line on the M?

Re: centreboard adjustment as part of normal sailing

Posted: Sat Jul 16, 2011 2:38 pm
by Sumner
vizwhiz wrote:I'm glad there's a post about this - my S has a swing-keel like the :macx: boats do (sure wish my S had a pretty icon like them too) :wink:
On the X, is the CB adjusted from below like the S, or is the line led above-deck like the DB line on the M?
I have the CB control line...

Image

...going to the cockpit....

http://purplesagetradingpost.com/sumner ... ng-19.html

.... and a number of other owners have done the same using 2-4 different ways to route the line from below the sink to the cockpit. I took the simple approach and one that has a 2:1 advantage for Ruth and has no maintenance issues as all of the lines are out in the open. Saying that I think the other guys also haven't had to mess with their more 'hidden' lines once installed.

Image

I made ours so that it just takes a couple seconds to detach it in the cabin and thought we would do that on anchor. So far in over 80 days out we never have. Ruth sits on that side at night and her head clears the line and the only time I'm on that side is when I'm on......

Image

.... the head and then I'm sitting lower as the cushion is gone.

Here is a link to Bob Hussey's mod and what others....

http://purplesagetradingpost.com/sumner ... ods-4.html

...have kind of copied one way or another,

Sum

Our Endeavour 37

Our Trips to Utah, Idaho, Canada, Florida

Our MacGregor S Pages

Mac-Venture Links