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constantly rounding up in fresh winds

Posted: Fri May 23, 2014 6:54 am
by DaveC426913
I went out last night single-handing to try out my new EZcleats.

Image

http://www.macgregorsailors.com/forum/v ... f=8&t=7257

(They work fantastic BTW, I don't even have to leave the helm bench and I have full control over all my sheets.)

Wind was about 15 knots, gusting to 22.

I reefed my main, and tweaked my genny between 40% and 70%.

This put me on a heel of maybe 15 degrees if I was lucky. But I found the same problem as always when in these conditions. The moment the boat gets up some speed (about 5 knots), it blows over to 25 degrees, then rounds up, and I lose it all, even with the wheel all the way to lee. No matter how much I try to stay on a straight course I find myself following a "scalloped" path.

I only have one reef in the main, so my options are to adjust the jenny. But I couldn't find a happy medium. If I'd switched out the furling jenny for a straight 100% (or less) jib, I'd be worried about not being able to douse it if as the winds picked up over the evening.

The gusts are one thing, I understand they throw a wrench into the works, but even in a steady wind this still happens. What can I do to keep a straight course in 15 knot winds?

Re: constantly rounding up in fresh winds

Posted: Fri May 23, 2014 8:40 am
by Loala
When I had my :macx: I had the same problem. I had to experiment for a while to make it better, First thing I did was rake the mast forward a little. Then I played with sheeting the main in more and spilling wind off the genao until I found something that felt good.

Try it next time & see if you notice a difference.

Re: constantly rounding up in fresh winds

Posted: Fri May 23, 2014 8:53 am
by DaveC426913
Loala wrote:When I had my :macx: I had the same problem. I had to experiment for a while to make it better, First thing I did was rake the mast forward a little. Then I played with sheeting the main in more and spilling wind off the genao until I found something that felt good.

Try it next time & see if you notice a difference.
Yeah. Mast rake is a bit of a mystery to me. guess I should actually measure it some day. It's certainly raked back more than other, larger boats on my dock. And it has a significant bow (forward in the middle). The bow is desirable, but maybe it's raked a little too much. After the turnbuckle under the furler drum, what's the next best way to reduce rake?

Re: constantly rounding up in fresh winds

Posted: Fri May 23, 2014 9:03 am
by Tomfoolery
Manuals for various vintages of the :macx: are under the 'Resources' link at the top of the page. Mast adjustment, including rake, is in there. http://www.macgregorsailors.com/manuals ... l_1996.pdf

Re: constantly rounding up in fresh winds

Posted: Fri May 23, 2014 9:18 am
by Loala
Good question. You need to take a look at your RF system and see where adjustment can be made to shorten the distance up. Could be something as simple as adjusting the headstay or unfortunately the RF length may need to be trimmed if it wasn't fitted to the correct length in the first place. Lots of variables. I'd ask around this forum and check the spec length to see where it should be and where others with the same boat are running it.

http://www.cncphotoalbum.com/doityourse ... reefer.htm

One other thing, take the mast off the boat and remove the RF and lay across 4 saw horses and look down it to see if it is bent. I had to put the mast on strategically places blocks of wood and have a friend sit on one side while I stood and bounced on the other side to get it straight. Once that is done we stepped the mast once again and re-tensioned all the stays. I found they were too tight. I loosened them one hole on the chainplates and the boat sailed much much better.

Re: constantly rounding up in fresh winds

Posted: Fri May 23, 2014 1:09 pm
by gabid
I would add to what has been mentioned here, reduce slightly the centerboard. In this way the board will be move aft together with the center of lateral resistance.

Re: constantly rounding up in fresh winds

Posted: Fri May 23, 2014 6:17 pm
by ronacarme
Mac X since 2001. Mac D since '88. Venture 17 since ' 80. Various since 1970.
In 15 kn (17+ mph) steady wind (and gusts to 20 kn (23 mph)) with factory reefed main and that much genoa out, my X would be overpowered.
I would run factory reefed main alone with CB line only about 3/8 to 1/2 out to balance the above and below water foils. Not more than reefed main plus 25 sq. ft. storm jib and 7 /8 CB line out.
Your heading up, with wind generated healing of 25 degrees, is a designed-in safety feature....better you head up than than put the mast tip and crew in the water.
Remember, doubling wind speed quadruples wind force on sails (hence heeling force), so reduce sail area early. You can more easily add sail area as the wind abates than reduce sail area as wind engendered violence increasingly destabilizes the boat.
Ron

Re: constantly rounding up in fresh winds

Posted: Fri May 23, 2014 6:38 pm
by beene
"The moment the boat gets up some speed (about 5 knots), it blows over to 25 degrees, then rounds up, and I lose it all, even with the wheel all the way to lee. No matter how much I try to stay on a straight course I find myself following a "scalloped" path."

1. you need to be on the main sheet 100% of the time, sheet out when the gust starts, stay ahead of the heel, anticipate by feeling the wind force change, you must not allow the heel to get accessive if you want to maintain a heading without rounding up

2. you mentioned turning the helm all the way to lee, don't do that, beyond 10-15 deg of rudder to your heading in these conditions, you will just stall out the rudders and they become a brake more than anything else

G

Re: constantly rounding up in fresh winds

Posted: Fri May 23, 2014 6:45 pm
by Wind Chime
My experience:

Best wind speed for our X is about: 10-16 knots (then we start to get overpowered)
Best heel angle for our X is about: 15-20 degrees. (lose steerage with less windward rudder in the water. Also, wind just starts to spill off the top anyway)

If the boat is balance well, 15 knots of wind and gusting, with a reefed main, and a 100% headsail, should spell perfect Mac Sailing. Should be maybe 20 degrees heel and running 5 knots over ground. You should be able to let go of the wheel and she should run a straight course and eventually turn upwind in time for lunch.

If you already have a reef in your single reef main, then your only choice is to reef the genoa, or play with centerboard. But in higher wind, you increase your leeway slippage with less centerboard down.

It’s about boat balance. Both lateral and horizontal.
- IF your center of effort is too far aft, the stern will push your bow into the wind. (weather helm)
- IF your heel is at 25-30 degrees or more, the shape of the hull will want to round you into the wind. (broach)

We have a double reef main and 150% genoa. In winds 16 up to 20 knots a single reef and a furled genoa to about 110% balances the boat. We also twist off a fair bit of wind in the top of the main, and may still need to ride the mainsheet a touch in the big puffs. Fully ballasted at about 5000 lbs, we are still a light boat for a 22 knot gust.

Re: constantly rounding up in fresh winds

Posted: Fri May 23, 2014 7:47 pm
by NiceAft
Dave,

There is a lot of good advise here, but as Beene suggested, be attentive to the main sheet. Be ready to release some sheet to bleed some wind.

One of the advantages of sailing a dingy, like a Sunfish, or a Phantom, is you develops quick reflexes. I found this useful in strong wind situations when in my Mac.

Ray

Re: constantly rounding up in fresh winds

Posted: Sat May 24, 2014 8:28 am
by DaveC426913
NiceAft wrote:Dave,

There is a lot of good advise here, but as Beene suggested, be attentive to the main sheet. Be ready to release some sheet to bleed some wind.

One of the advantages of sailing a dingy, like a Sunfish, or a Phantom, is you develops quick reflexes. I found this useful in strong wind situations when in my Mac.

Ray
To be clear though, the issue here is not about the puffs, this happens in a steady wind.

Re: constantly rounding up in fresh winds

Posted: Sat May 24, 2014 8:58 am
by NiceAft
DaveC426913 wrote:
NiceAft wrote:Dave,

There is a lot of good advise here, but as Beene suggested, be attentive to the main sheet. Be ready to release some sheet to bleed some wind.

One of the advantages of sailing a dingy, like a Sunfish, or a Phantom, is you develops quick reflexes. I found this useful in strong wind situations when in my Mac.

Ray
To be clear though, the issue here is not about the puffs, this happens in a steady wind.
Yes. If in the conditions you described, your boat has a tendency to be over powered, then keep the main sheet in hand and ready to release.

I have the same problem with Nice Aft, and since I have a muscle head main, maybe even a greater problem with with keeping the sails well balanced to stop the wind from overpowering my :macm: . I have two reef points, but as people with young children learn, SPIT HAPPENS :!: :)

Ray

Re: constantly rounding up in fresh winds

Posted: Sat May 24, 2014 10:38 pm
by bscott
In addition to all of the above, since the X does not have a traveler it is important to have a strong boom vang to keep the boom from rising and creating too much bag in the main as you dump the main sheet-thus over powering the main.
If you are still equipped with the original oem Doyle sails you will not be able to sail a straight course-period.

Check to make sure your rudders are fully down and parallel.

Bob

Re: constantly rounding up in fresh winds

Posted: Sat May 24, 2014 11:40 pm
by Steve K
Hold on fellows.............
Wouldn't it seem that in steady wind, as speed increases, the apparent wind moves forward? I think I am usually able to sheet in as boat speed increases....... (could be wrong comments welcome). Haven't had a X boat in awhile, but never found the centerboard position to be real critical where this issue is concerned. (it can be used in this way, but something else is going on here).

I would agree with the mast rake idea. I've seen many X boats that have way too much rake in the mast. This will cause premature round ups for sure. When my X boat preformed it's best, was when I had almost no rake in the mast. I had to shorten the forestay a few inches to do this.

Another thought........ I've also seen many Macs (particularly those with furlers) sporting a very loose forestay. This should not be and could be part of this very problem. In fact, all the stays and shrouds should be fairly tight, except for the backstay. It just needs to be snug. In the features section is the article about tuning the fractional rig. Read it over.

mho
SK

Re: constantly rounding up in fresh winds

Posted: Sun May 25, 2014 10:06 am
by ronacarme
Bob...The original Doyle sails are not the most expensive or best, by any test, but my X can still sail a straight course with its 14 year old original factory sails, if not overcanvassed and with CB positioned to balance the sailplan. I mention it because it is less expensive, and thus perhaps better for someone new to an X, to experiment with reducing sail area and adjusting CB position for a while, rather than to pay big bucks for new sails.
Actually, the X has adjusted quite easily to sailing in winds from a whisper up to the high teens (in mph). Tacking is not thru 90 degrees in high wind mode (factory reefed main, no headsail, CB line about 3/8 out) but with heel angle less than maybe 20-25 degrees, the X will close reach and pretty reliably hold an average course thru the waves.
When the winds get higher than that, we try to avoid the discomfort and stay in port.
Ron