Ancor and jib questions

[AndreiT]

This is my first season on mac97x.
I sail it on lakes Ontario and Simcoe.
For last week i lived on the boat in marina and sailed it duiring the day.

While i was sailing i noticed, that my jib's trailing edge does not looks stright.
It is like a scoop. I tried all positions for the rollers, different jib sheet tention,
but i was not able to make trailing edge stright.
What do i do wrong? Why trailing edge looks like scoop? My Jib made by Doley.
I think that scoop on trailing edge slows down boat and affects main sail too.

Second question is about ancor.
During the day i ancor my boat at 6' deep bay to swim, snorcle and do other fun staff. I make ancor line arond 30' long.
I have noticed, that boat swings on ancor line left and right almost +/- 45° to the wind.
What do i do wrong? I tried to retract keel and rudders. It helped a little bit, but not much.
All powerboats around me always stady and point to the wind without swinging. Could you advice me what do i do wrong and how to ancor properly to eliminate swinging.
Thank you

[JustSail]

AndreiT,

Do you have a jib or a genoa. Which tracks are you using for this sail? The ones on the cabin top or the ones back on the cockpit coamings? It sounds like you've tried all the stops on the track you are using, I'm just not sure which one you are using.

The Mac sails at anchor. It 's a common issue. Some of suggested using a bridle, some use a stern anchor, some just put up with it. Search the forum and you will find several ideas for a solution to this. You probably have to just try a few and see what works.

[victore]

The Mac is a sailboat & will swing differently than a power boat at anchor & mooring. I am at a mooring in a small marina & am surprised at how the next to me swings in relation to my . The trimarons go in other directions. I wish I listened more in physics.
Is the jib or jenny the right size for your boat Did you adjust the sliders on the tracks
Good Luck.
Vic

[puggsy]

I partly solved the swinging problem by fitting an extra off-centre bollard...the swing now is only to the off side of the bollard.


Puggsy

[Love MACs]

Puggsy, it looks as if that bollard is merely glued/epoxied on???? Surely that can't be the case. And how exactly does that attached to the rode? I can't figure how it is used, at least from the pic.


Allan

[Frank C]

For anchoring in mild conditions only ... rather than cleating your anchor line at the bow cleat, try tying the anchor line to the aft pulpit stanchion. You may tie-off to the aft stanchion of the pulpit on either side, port or starboard.

The physics:
The natural curvature of your hull, itself, is repeatedly "tacking" through the eye of the wind.
Snubbing the hull at either forequarter prevents the bow from passing across the wind.
This reduces the swing angles from 120 degrees to about 40 degrees.
The pulpit stanchion isn't the best choice of an anchor snub, but it will work for anchoring in mild winds.

[Scott]

While i was sailing i noticed, that my jib's trailing edge does not looks stright.
It is like a scoop. I tried all positions for the rollers, different jib sheet tention,
but i was not able to make trailing edge stright.

Do you mean like this??



This is a pretty good set. (very light winds though) If you get the trailing edge of you sail "straight", I doubt your boat would sail forward. You would choke it out and stall any lift generation.

OK set "stiff winds" (and reefed)

[AndreiT]

Thank you for pictures. Your jib is perfect.

My jib looks different. If you imagine horizontal section of your jip. It would looks like perfect airfoil or airplane wing upper serface.
But if i would make same crossection on my jib, it would looks like airplane wing with flaps extended. So trailing edge have a scoop.

I have to make a picture to make it clear.

Andrei

[johnnyonspot]

Regarding the jib, sounds to me like maybe you have a leech line in your jib and its too tight, causing the very trailing edge to be cupped, or have a curved lip. Am I right? The leechline is a small diameter line sewn into the leech of the sail and is used to keep the leech from fluttering. If you have this cupping or curved lip, again, sounds like your leech line may be too tight.

[c130king]

I fly a 150 Genoa but....

would sliding the jib car on the cabin top back towards the cockpit help to pull the leech a little flatter and allow less "curve"? Seems like it would.

FWIW,
Jim

[AndreiT]

My jib shape is the best, when jib car is at the end of track on the cabin top back towards the cockpit.
Johnnyonspot point that leech line in my jib is too tight. It looks like the best explanation for scoop on trailing edge. Thank you.

Is it possible to fix leech line or i have to buy another jib? If fix is complicated i whould rather buy new jib.
If i would decide to install roller furler, whould i be able to use my current jib or i will have to buy new one anyway?

Andrei

[Hamin' X]

As a general rule-of-thumb, the higher your point of sail, the further back you want the jib car. Close-hauled, all the way back. Running, all the way forward. There are many variables involved. Condition of sail, wind speed, traveler position, etc. Part of the fun in sailing is experimenting with sail trim.

On a recent trip in the San Juans, I chartered a Pacific Seacraft/Crelock 34.
Osprey Moored in Blind Bay, Shaw Island
This is a blue-water, passage-maker, with heavy offshore sails. It is a mast head cutter (sloop rigged for chartering), with a 120% genoa. In light air, e.g. <4kts, I was having trouble filling the genny while running without using the whisker pole (too much of a pain for short runs). I finally came up with a system of sailing about 5º windward of ddw, sails set wing-on-wing and sheeting in the main farther than normal. This allowed the wind to flow off the back side of the main and fill the genny, while minimizing the chance of an accidental gybe. Worked great. The only problem that I had was when gybing, I had to reach up and jerk the boom to get the mainsail to snap the full battens to the lee side, as the air was too light to force the battens to reverse camber.

Schedule play days, with no destination in mind and get out and experiment. You will be amazed at how rapidly your skill level improves and that the Mac turns out to sail better than the naysayers think. ~Rich

I fly a 150 Genoa but....

would sliding the jib car on the cabin top back towards the cockpit help to pull the leech a little flatter and allow less "curve"? Seems like it would.

FWIW,
Jim