Tabernacles - Mast Hinge

[jdoorly]

Hi Scott, glad to see everything is working out, but sorry you circumsized you mast- check your spam email, they have pills for that.

A shorter mast will cause more rake. I suggest putting temporary shims or wedges under the mast until the shrouds (sidestays) are tight, assuming you haven't changed their adjustment. Then your rake should be the same as before. Replace the wedges with something the same height but sturdy.

Also, let the main halyard hang free. It should hang some distance abaft the mast. Make a mark on the boom where the halyard contacts it.

There is some ambiguity in measuring mast rake so I suggest a new standard: Just mark the boom at 1 foot from mast with "3 degrees", at 2.1 feet with 6 degrees, at 3.2 feet with "9 degrees", then optionally interpolate to your hearts content. I used the formula A=B(tan a) where "A" is the distance along the boom (1, 2.1, 3.2 feet), "B" is the distance B2 to B3 (20.5 ft), and "a" is the angle at the masthead, i.e. 3, 6, 9 degrees. Then see where the main halyard touches the boom when it hangs free. Normal mast rake is in the center of this range.

To evaluate mast rake you need to sail on a beat (as close to the wind as you can [about 45 to 50 degrees true off the wind]) in an 8 to 10 knot breeze. The indicator of balance is the tiller, in this breeze the tiller should be centered on average. If the tiller needs to be constantly pulled towards the high side that's weather helm; a bit is good (it makes the boat act like a foil and pulls it toward the wind) but too much will cause the boat to slow due to friction, will put unnecessary and potentially destructive side loads on the tiller and rudder, and will tire the helmsman's arm. The solution to regain balance is to tighten the jib sheet and/or loosen the mainsheet and/or raise the centerboard halfway.

[hectoretc]

Thanks Jay,

I did adjust the side stays to see if I could get the slack out, but this time I had the foresight to mark their original settings so I can put them back.

Thanks again for the suggestions...

[hectoretc]

You essentially made a locking pin out of a bolt by drilling the hole in the removable bolt. Is that because you couldn't find a 1/2 inch clevis pin or other hardware to fit that hole, or is there something else in play at that point where you wanted a real bolt in there?
A clevis would work fine, but I wanted to minimize play. Also True Value is 5 minutes away but only has a zinc clevis, and West Marine is 60 minutes away and has a stainless clevis.

Hi Jay, This is revisiting a pretty old topic but about 2-3 weeks ago (time flies) I was walking through a Northern Hardware store looking for something else, and found a perfect clevis pin for my mast hinge.



It fits "exactly" right and the cotter pin is snug against the mast hinge. It could not be a better fit. Hmmm... I was just looking at these pictures again and realize that for what-ever reason I'd pulled a couple screws out of the stop plate on the hinge, not the 3" x 5" structural support plate, but the smaller stop plate that prevents the mast from going beyond vertical when raising it. I guess I should make a note to replace them next time I'm at the boat. Wonder why I took them out... oh well...
Also, you can't see it here, but I ended up using the mast step base plate that I removed to fabricate the adjustable step, and inserted it (upside down) into the top of the lower mast stub. Just had to grind a tiny bit off so the upper mast section would clear when raising and lowering.
Thanks again for all of your support on this particular portion of the project. It works fantastic...