Playing the mainsheet with the stock block

Moderator: GreenLake

Playing the mainsheet with the stock block

Postby KingsTransom » Tue Oct 18, 2016 12:16 am

The stock mainsheet block on my DS II has the cam cleat on top and the keeper strap (or whatever it's called) on the bottom. Both are attached to the sides of the block, giving no other route for the line to go other than through the cam cleat or keeper strap. Since one normally sits higher than the block, it seems like one would constantly need to use one's foot to push the mainsheet down and out of the cam cleat - not the best way I can think of to sail the boat, especially when conditions require you to actively play the mainsheet. How best to do this?
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Re: Playing the mainsheet with the stock block

Postby GreenLake » Tue Oct 18, 2016 12:21 am

This is a known issue; I regard this as a defect -- I would replace the setup with one that releases by pulling up.

Read some of the older posts; we've discussed this not so long ago.
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Re: Playing the mainsheet with the stock block

Postby K.C. Walker » Tue Oct 18, 2016 8:18 pm

I agree with Greenlake about the OEM main sheet set up. I thought it was a capsize waiting to happen. It is one of the first things that I replaced. I watched eBay during the off-season and found some great new/old stock Harken ratchet blocks and a Ronstan swivel cleat. Not being in a hurry, I was able to get some really good prices.
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Re: Playing the mainsheet with the stock block

Postby TIM WEBB » Tue Oct 18, 2016 9:42 pm

The Red Witch originally had an "up to release" cleat, which I eventually replaced with a stand up block (Garhauer) that just happened to have a "down to release" cleat, and I found I liked it much better. Why? Think about it: rarely is the block standing straight up, only when sheeted in as tight as possible, and even then the cleat has somewhat of an up angle to it. When the angle of the boom to boat C/L is higher, the block/cleat leans over towards it, following the mainsheet, and the cleat angles even further up. Therefore a tug on the sheet in the direction of the gunwale results in a release, not a set. I found myself using my foot to set, rather than release.

Now of course I realize that setups differ, and if it was the kind where the cleat is at a fixed angle, and rotates independently of the block, I'd have definitely gone with the up to release setup.
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Re: Playing the mainsheet with the stock block

Postby GreenLake » Tue Oct 18, 2016 10:57 pm

TIM WEBB wrote:Now of course I realize that setups differ, and if it was the kind where the cleat is at a fixed angle, and rotates independently of the block, I'd have definitely gone with the up to release setup.


Fixed angle is what I have (and what, apparently was stock in some of the early DS1s).

Now, there's one more variant; some brands/designs limit the swivel to 270 degrees (not full 360). I don't understand the reason for that, I always end up bringing the main sheet across without paying attention whether I do it in front of or behind the swivel. With full 360 rotation I can make the swivel follow the sheet no matter how I do it. I have the other setup on another boat and it can get really awkward if the only way to straighten things out is to bring the sheet around the swivel.
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Re: Playing the mainsheet with the stock block

Postby TIM WEBB » Wed Oct 19, 2016 12:22 am

Hmmm ... interesting! In our previous "debates" on this issue, I had not considered that the fixed cleat swivel did not swivel 360. My only beef w/ TRW's mainsheet setup was that the boom block would not follow the CB trunk block through a tack, and after a couple of tacks I'd have to reach up/over and "untwist" the mainsheet, no matter whether I brought the sheet over in front of or behind the CB trunk block.
Tim Webb
1979 DS2 10099 The Red Witch
(I used to be Her "staff", in the way dogs have owners and cats have staff, but alas no longer ... <pout>)
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Re: Playing the mainsheet with the stock block

Postby MookaCB » Wed Oct 19, 2016 11:59 am

I use up to release on my main sheet. I tried both ways, but when racing (or sailing hard) it is easier to pull up to dump the main sheet especially when you are hiked out. Sometimes I will have to use a foot to secure the cleat when sailing close hauled, but I don't often cleat it when close hauled anyways.
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Re: Playing the mainsheet with the stock block

Postby GreenLake » Wed Oct 19, 2016 12:10 pm

TIM WEBB wrote: My only beef w/ TRW's mainsheet setup was that the boom block would not follow the CB trunk block through a tack, and after a couple of tacks I'd have to reach up/over and "untwist" the mainsheet, no matter whether I brought the sheet over in front of or behind the CB trunk block.


You must have had mid-boom sheeting on TRW, then. My setup has the mainsheet continuing aft along the boom, and that means the block on the boom doesn't swivel at all. And, before you ask, I've never noticed that the main sheet would get slowly twisted over time - as you might naively expect.
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Re: Playing the mainsheet with the stock block

Postby Alan » Wed Oct 19, 2016 12:16 pm

I have a Ronstan RF7 swiveling cam cleat in my box of shiny stuff:

http://www.ronstan.us/marine5/product.asp?prodno=RF7.

Here's what Ronstan has to say about it:

"Twin rows of ball bearings support the cleat arm, and stops are provided to limit rotation to 260°. The rotation stop on the cleat arm moulded cleat arm cradle part can be cut off to allow full 360° rotation."

No mention of the advantages of either approach, though. And to really confuse the undecided, the angle of the cam cleat can be changed, and the cleat can be mounted to allow upward or downward uncleating.
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Re: Playing the mainsheet with the stock block

Postby TIM WEBB » Wed Oct 19, 2016 12:33 pm

GreenLake wrote:You must have had mid-boom sheeting on TRW, then. My setup has the mainsheet continuing aft along the boom, and that means the block on the boom doesn't swivel at all. And, before you ask, I've never noticed that the main sheet would get slowly twisted over time - as you might naively expect.

No, I wouldn't expect the sheet to get twisted, even if you brought it around in the same direction all the time, because it would have the tendency to "self untwist" as it is played out/sheeted in? Yes, TRW has the standard DS2 midboom sheeting.
Tim Webb
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(I used to be Her "staff", in the way dogs have owners and cats have staff, but alas no longer ... <pout>)
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Re: Playing the mainsheet with the stock block

Postby GreenLake » Wed Oct 19, 2016 12:55 pm

That one looks like a well-thought out product.

The thing with cleating up or down: the idea about pulling up to cleat could have been that, when uncleated, the mainsheet falls down and gravity keeps it from accidentally re-cleating, if you throw it off completely. However, if the angle of the cleat is too low, you can't play the mainsheet without coming into contact with the cleat and it can grab the sheet when you don't want it. (When playing the mainsheet it is under tension, so there's no effect on gravity).

The idea about pulling up to uncleat is that there's usually nothing to restrict your ability to pull a little higher, but, in the opposite case, if the angle is wrong, you can end up not being able to go low enough and still clear your seat or thighs or whatever else is in the way.

In the end, what matters, is that the angle is such that you can play the mainsheet (from all seating positions) without the cleat grabbing it by accident; and such that you can quickly and positively uncleat the sheet and "throw it off" in an emergency, without it re-cleating itself or needing a foot or other special effort.

So, with the Ronstan swivel having three angles to choose from, it might be possible to set it up at a steep enough angle where "release down" works. The OEM fittings on the DSII did not work for me in that orientation when I tried them, while the OEM fitting from the early DS1s has always worked.

I am curious about one of its features, though: "Adjustable ratchet system prevents the arm from falling to leeward." How precisely is that supposed to work? Presumably, the ball bearings in the base cut friction to the extent that the swivel arm could move in response to gravity and not just pull. Still can't figure out how they work a ratchet, when you need to pull the arm to the other side on the opposite tack. The '60s era fitting on my boat has enough friction that it won't "fall to leeward", so I'm good, I think.
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Re: Playing the mainsheet with the stock block

Postby Alan » Wed Oct 19, 2016 6:58 pm

Mainsheet swivel cleat bottom view.jpg
Mainsheet swivel cleat bottom view.jpg (144.91 KiB) Viewed 10588 times


Above is a bottom view of the Ronstan RF7. The ratchet consists of a cogged disc and ball (A). Tension on the ratchet is supplied by a flat spring (B) and adjusted with a screw (C). Access to the screw is through a hole in the side of the base (D).

Mainsheet swivel cleat ratchet adjusting screw.jpg
Mainsheet swivel cleat ratchet adjusting screw.jpg (166.57 KiB) Viewed 10588 times


The second photo is another view of the tension adjusting screw (D). The Ronstan website shows an Allen wrench (I have a slotted adjusting screw, not an Allen). The adjusting hole is also shown in a slightly different location in the base than what I've got.
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Re: Playing the mainsheet with the stock block

Postby GreenLake » Thu Oct 20, 2016 12:47 am

Wow. What service!

Seems weird somehow to have ball bearings to reduce friction and then to reintroduce it via this "ratchet" mechanism.

The pictures make clear that it's not a one-directional ratchet. (In fact, it appears that the term "ratchet" may not be entirely accurate if it's not one-directional, but I'm no mechanical engineer, nor do I know what alternative term would apply).
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Re: Playing the mainsheet with the stock block

Postby Alan » Thu Oct 20, 2016 1:17 pm

Haven't had a chance to play with Photoshop in a while. :)

I'm not a mechanical engineer either, but it might qualify as a cam wheel, since the rotary motion of the disc causes reciprocating motion of the ball.

I finally figured out why there's a ratchet/cam wheel/noisemaker. Ronstan says this: "Adjustable ratchet system prevents the arm from falling to leeward." I tried it with a jury-rigged mainsheet, holding it up in the air and tilting it to simulate heeling. With the tension released, the swivel arm does fall to leeward if there's any slack between the mainsheet blocks while the bitter end is held loosely by the crew. The mainsheet twists as it happens. Presumably, the mainsheet crew is sitting to windward at the time. Whether that would be a nuisance, or maybe a real problem, I can't tell without installing the setup and sailing with it, which ain't gonna happen soon, unfortunately.
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Re: Playing the mainsheet with the stock block

Postby K.C. Walker » Thu Oct 27, 2016 2:08 pm

The RF 7 is what I have on my boat. It's a great piece of equipment! After eight seasons of use it still seems brand-new. It's one of those pieces of hardware that I really don't think about anymore because it's never in the way and always does what it's supposed to. With that and a good ratchet block, playing the main sheet feels very natural.

The other really nice upgrade is actually the line itself, that is, using a single braid line that is designed for sheet rope. I use New England Ropes Bzzz line and it has been excellent. This line never gets twisted up and stays nice and relaxed… and almost tangle free. I use it on my main at 8 mm and my jib at 7 mm and I also use the 7 mm for my UPS which is like 70 feet of line. It's really important when you have that much line that it does not tend to tangle.
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