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8:1 downhaul for old 18
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Author:  John Eaton [ Fri Jul 29, 2005 8:37 pm ]
Post subject:  8:1 downhaul for old 18

I've had a look at the downhaul system on one SX. I have no clue if it was factory or not.

I have not seen anything in Hobie illustrated parts list (unless I'm looking in the wrong place).

What are the recommendations for retrofitting an '82 mast with the 8:1 downhaul?

Author:  flumpmaster [ Sun Jul 31, 2005 4:38 pm ]
Post subject: 

I would recommend you fit a 4:1 with 2:1 cascade. This gives 8:1 mechanical advantage with fewer blocks than a straight 8:1 system. A lot of Hobie 20's use this system in my area (Texas),

Stick with me here 'cause I don't have a camera handy and this can be hard to describe in words...

Fit a double block (e.g. Harken micro 226) to the grommet on the main using a shackle.

Tie some thin line (3/16") to the end of a single block (e.g. harken micro 224). A couple of feet should be ample. Repeat this on a second block. So you now have two blocks, each with a piece of line 2ft long tied to then (bowlines work well).

Thread each line from the back of the boat through one of the pulleys on the double block on the bottom of the main. Pull the lines until the single blocks are up against the double.

Then thread the lines inside the mast rotator to a likely looking spot about 6-8" up from the base of the mast on each side. No magic in choosing the spot - just make sure the angle on the line from the double block looks good and it isn't rubbing on anything. Once you have marked your spot on each side fit a suitable jam cleat (I used self tapping screws and drilled a pilot hole first).

Jam the lines through the cam cleats on each side and tie the tails together at the front of the mast (just in case the cleats were to slip). Trim the excess line to suit.

Now mount your self a couple of pivoting exit cams (e.g. Harken 291) on either side of the mast a few inches up from the base. Fit a single block (e.g. harken micro 224) on the back of the mast down low. I think I rigged some kind of bracket off the pin that secures the pulley for the mast halyard at the base and then tied my single block off to it.

Now thread your down haul line through your pivoting exit cam, up to the single block which is jammed up against the double on the main, down to the single block at the base of the mast, back up to the other single block at the main and down the the other pivoting exit cam. Viola - a kick ass down haul with very little friction. You can leave the down haul lined long enough to tie it to your trap wire or to the end of the cross bar - letting the crew play the down haul while out on the wire.

If you want to cut down on the cost then just use jam cleats instead of the pivoting exit cams (you may have jam cleats in this position already).

If I get time I'll take some pictures of this set-up.

Chris.[/url]

Author:  John Eaton [ Wed Aug 03, 2005 8:00 am ]
Post subject: 

Chris,

Awesome. No pic's necessary, I've got a visual, great verbal description.

I'm always concerned about spending more than I have to, and/or is an "extra" expense worth the gained advantage, and is another doodad going to be in the way more than it's used (my general philosophy is cleaner is better).

So let's talk about a pivoting exit cam vs. a jam cleat and "letting the crew play the down haul while out on the wire."

Are we going to do more than setting changes at the marks?

My 18 experience is limited, but if the wind is puffy is it worth "playing" with in this situation? I mean even if you bear off in a lull you're going to rapidly loose speed. Is this the magic missing link?

Comments welcome.

Author:  Jcraig [ Fri Aug 05, 2005 8:42 am ]
Post subject:  Downhual

Murarys sells a nice 5:1 downhual for the H18. Its worth it if you want to shell out the $150.00. No drilling required :D .

Live Slow and Sail Fast!

Jason

Author:  flumpmaster [ Wed Aug 24, 2005 7:16 pm ]
Post subject: 

Quote:
So let's talk about a pivoting exit cam vs. a jam cleat and "letting the crew play the down haul while out on the wire."

Are we going to do more than setting changes at the marks?

My 18 experience is limited, but if the wind is puffy is it worth "playing" with in this situation? I mean even if you bear off in a lull you're going to rapidly loose speed. Is this the magic missing link?


I like to be able to play the down haul when going to weather - which is why I favor the pivoting exit cam. I would only start pulling on the down haul once double trapped, but in those conditions it can be nice to ease it a little and get a bit of power back if the wind eases up.

On some very powerful boats I've sailed like the Nacra 6.0NA the crew can play the down haul to weather. On a Hobie 18 it doesn't seem as responsive but I still like the option.

Chris.

Author:  John Eaton [ Sun Aug 28, 2005 5:17 pm ]
Post subject: 

Let me preface this by stating the stock cheek block was broken when we got our boat, so our downhaul to date has been a makeshift 2:1.

WOW! :shock: Night and Day! :D

Sooooo glad I spent the time to scope out a deal on some pivoting exit cams, this cascading system is literally amazing, the main is fahreaky tight! Paul thumped the main and said it sounds just like the marching band bass drum. I spent right at $105 including shipping by being patient. We finished install today. The wind is dead here cause of that nasty hurricane, cannot wait till this weekend. You know how some mods or tweaks made you've got to prove out on the water? This is like, OHHH MAN, you just know it's right on!

Praying for the folks on the Gulf Coast.

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