Hunter 170 Tunning Guide
I have been in contact with JY about a tuning guide for the h-170. As it turns out, there is none. So, I talked to the lead tech, and they do not use any gages on the shrouds. They just guess. I know, I know. Not a very good plan. I am working on some figures that seem to be promising. I am not done yet because I need to try them out under various conditions. However, I feel the following is pretty close. Alan is right of a 1.5% mast rake, but generally for a masthead rigs. The Hunter 170 is a fractional rig, so it will be closer to 1%. Also, 15% tension on the upper shrouds are great for a masthead rig, but for the h-170, 20% would be maximum. I am finding that 15% is good for light wind, 18% for all around sailing conditions, and 19% for stronger winds. Remember, within reasson, too tight is safer and easier on your boat than too little tension. Also, the higher the tension, the better you point because of the tighter forestay. And with lower tension, the better your down wind performance in light wind. There is a trade-off. Mast Bend: 1% of mast height from head to boom. Example: h-170 mast = 24’1” (289”) Mast head to boom = 19.75’ (237”) 237” x 1% = 2.37” 1/8” cable breaking strength = 2100 * 1/8 “ @ 2100 lbs. x 15 % = 315 lbs. -------- Masthead rig, to prevent to excessive mast bend use only 15 %. * 1/8 “ @ 2100 lbs. x 19 % = 399 lbs. -------- Fractional rig w/swept back spreaders, tangs even with forestay. The lower shrouds are much more variable. I am finding that if you have upgraded to a Boom-Kicker and an 8:1 vang, then you can have a very light tension on the lowers. I like about 50 lbs., (measured with vang off). When you put on a lot of vang with an 8:1 and the B&R rig, that adds a lot of tension on the lowers. When I am completely satisfied with my figures, I will forward them onto Hunter. Hopefully, they will add the information as an amendment to the h-170 manual. Danny
