Com-Pac Yacht Owners Association

Com-Pac Model Specific Discussions => CP-16's => Topic started by: Urban Hermit on April 20, 2025, 10:48:37 AM

Title: How much mast rake?
Post by: Urban Hermit on April 20, 2025, 10:48:37 AM
The first sail of Tilling Time showed a pronounced tendency to fall off the wind.  I'm under the impression that raking the mast may reduce or eliminate that.  Question:  How much to rake the mast, if at all?  I"m going to have a quick-release put on the forestay and that's a perfect time to allow for mast rake. 
Title: Re: How much mast rake?
Post by: soilgod on April 20, 2025, 07:16:02 PM
Raking the top of mast to aft will increase weather helm.  Raking aft moves the center of effort of sail plan aft.  Rake in a moderate wind say 10-12 knots till you have say 5 degrees of weather helm. 
Title: Re: How much mast rake?
Post by: Cpy23ecl on April 21, 2025, 06:32:45 AM
I can't say I know what the proper amount is, but my eclipse arrived from the factory with a forward rake.  I asked about that and was told that it was to compensate for the mast rake moving aft in the water due to the weight of people in the cockpit.

What I found was that the boat would go into irons while tacking in light to moderate wind.  This behavior was eliminated when I rake the mast aft a fair amount from the factory setting.
Title: Re: How much mast rake?
Post by: Urban Hermit on May 18, 2025, 08:02:15 AM
I'm having a rigging shop put a quick-release on the forestay with instructions to add an inch overall with the turnbuckle(s) adjusted to mid-point.  I'm hoping the turnbuckles on the side stays have enough adjustment to take full advantage of the inch.

And thank you, soilgod and Cpy.
Title: Re: How much mast rake?
Post by: Urban Hermit on June 02, 2025, 04:07:16 PM
I had a new forestay with a quick release attached, one inch longer than the original, which can be shortened to the original length.  Any guesses how much rake the extra inch will create, assuming perfect vertical to start with?  I could knock deep scaly rust off my math and figure it out but one of you is probably a math whiz or just knows.
Title: Re: How much mast rake?
Post by: soilgod on June 03, 2025, 03:47:06 PM
see how it sails and handles.  Refer to previous comments.  never mind the exact math.
Title: Re: How much mast rake?
Post by: Urban Hermit on October 22, 2025, 07:37:00 PM
The Executive Department and I had a very nice sail today, main and jib, on Bayou St. John, inland waters southwest of Pensacola.  About 8 knots varying from N to NE.  I set the quick release on it's middle attachment hole, which, when I dry-stepped the mast a couple days ago at a nearby parking lot (trees at home), seemed to give a slight rake.  Tilling Time handled just right -- a couple to five pounds of force on the tiller to weather.  She was against the transom, I was half-way back.  She's dainty; I'm 187 or so dressed.  I think I hit the sweet spot.