Measuring Mast Rake

[JMonda]

Hi Folks,
I want to tune my Mac 26S. I think the mast is too far forward. I calculated that it should be roughly 16 inches from a hanging halyard to the mast at about 2 1/2 feet above the bottom of the mast. Does this seem reasonable?

I measured it today on the water. I tried earlier on the trailer but I couldn't get comfortable with any sort of measurement. On the water the wrench I tied to the halyard was running off to starboard and I couldn't get a decent measurement.

Any advice?

Thanks much,

Jerry

 

[timebandit]

I use the water line as a fore-aft reference line.

With the boat on the trailer and using a carpenter level---

Level stb-port with a 2x4 across the coclpit seats by jacking and blocking the trailer.

Level fore-aft with the level hung from the stantions and parallel to the water line, adjust by jacking the trailer.

Now go on board and adjust the mast left and right using the level.

Next adjust the the rake to 1/2 bubble aft and see how the boat sails.

1/2 bubble is where my boat sails the best but yours may differ.

Remember that this assumes that you boat sits on it's water line.

 

[Mike B1026]

The Macgregor manual specifies 3degree tilt aft.

If memory serves me, the mast should actually be tilted aft about six inches. Someone might want to double check that.
http://www.macgregorsailors.com/manuals/Mac26S_Manual_xxxx.pdf

 

[Erik V]

Try using an angle locator that is designed to be held up against a pipe or wall, most have a magnet in the base to hold it in place. Obviously it won’t hold to aluminum but you can hold it up against the mast with double back tape. The cost is minimal I picked on up at Home Depot. With the boat in the water you can check the mast’s actual fore/aft and port/starboard position. When I did mine everything was out of the boat except the battery and anchor with the motor mounted. I used 1.0-1.5 degrees, this setting took some of the weather helm out of her. It was quick to do and seem to work well. Mast rake angle to floating water line depends a lot on how the boat is loaded but I found this to be a good starting point. I hope this helps.

Erik

 

[tkanzler]

The manual says about 3 degrees aft, which is about .628 inches per foot of mast. The mast is, I believe, 28 ft, so that's a hair over 17-1/2" at the foot of the mast, or 16 inches at 30 inches up (same as you got). At least that's what comes out using 3 degrees and 28 ft. Whether or not that sails well I couldn't say.