T.R | Title | User | Personal Name | Date | Lines |
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777.1 | Whistle a Happy Tune!! | CSSE::GARDINER | No more Monkeys! | Wed Mar 23 1988 16:51 | 50 |
| See note #8 for a little different discussion, but worthwhile.
A couple of things you need to watch out for: First, make sure
that if your mast is stepped on deck that you won't put too much
pressure on the cabin top by cranking down on the shrouds. They
can create a lot of tension if not properly tightened.
Second, set up your mast and then use the Main halyard to judge
the mast center. To do this tie off the halyard so that the shackle
can be brought tightly to one rail in line with the mast. Then
move to the other mast and see if the shackle touches the rail with
the same pressure on the halyard. When you have this even the top
of the mast is in the center of the boat. The shrouds should be
tight at this point, but not tight enough to make a ringing sound
when hit with a wrench or screwdriver.
Third, sight up the mast to see if it is straight from bottom to
top. Adjust lower shrouds until it is.
You now have a straight mast that is in the center of the boat.
The next thing you do is go for a sail. When on a close reach,
the leeward shroads should be just loose. The test I use is to
try to move the turnbuckle back-and-forth on its lower clevis pin.
If you can easily then tension is OK. If not, it is too tight.
If the shrouds need to be tightened OR loosened stay on the same
tack and adjust the upper and lower shroud turnbuckles (counting
the turns) until the shrouds "feel" good. Then back off 1/2 the
number of turns.
Then take the opposite tack and adjust the opposite shrouds the
same "effective" number of turns from the previous test.
This should set you up coorectly.
Adjustment of your fore and aft stays will depend on how your boat
handles. Moving the top of the mast back and forth to balance the
helm. The upper shrouds should have no effect on this, but the
lower shrouds will need to redone or a "hook" will result from the
center of the mast being held in place by the double lowers (if
you have them, of course). If you only have single lowers that
attached at the same chainplate location as the uppers then no change
is needed.
Good luck and happy sailing!
Jeff
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777.2 | | GRAMPS::WCLARK | Walt Clark | Wed Mar 23 1988 18:17 | 24 |
| I agree with Jeff that there should be some slack in the leward
shrouds with 1x19 wire. The wire stretches temporarly under load
which is what causes the slack. Naturally larger wire would stretch
less and rod rigging even less in a give application. If you tension
things too much by doing the tighten-the-lee-shroud, you will only
cause permanent stretching (and again loose shrouds), overload the
chainplates (possibly oilcanning the hull - depending on where the
chainplates tie in), compressing the deck (maybe distorting how
things fit below) and accelerating wearout of the wire, if not outright
failure of a fitting.
I wouldnt expect much slack on lower shrouds underway, since the
wire is shorter and generally under lighter load.
A rule of thumb I heard once is that you can tighten upper shrouds
as much as you are able to (with ordinary tools) dockside, but
if they are too slack for your tastes underway, dont tighten them,
you need larger shrouds (or lower stretch types). For those of you
who dont like rules of thumb, there are tension gauges which give
you repeatability and a sense for how close to the limit you are
tensioning a given wire.
Walt
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777.3 | | DELNI::FACHON | | Thu Mar 24 1988 13:45 | 15 |
| Jeff's method for centering the mast is fine if you have
a center-pull halyard. Double check to be sure. If not,
you'd need to compensate for the difference.
About slack, the lee upper-shrouds should definitely have play --
They should not slop around, but neither should they be under
significant load -- enough to keep them straight. When adjusting
lowers, as long as the turnbuckles are well lubricated and you're
sailing in moderate wind -- 10 to 14 knots -- adjust the weather
side. Saves a lot of tacks and you'll loose fewer cotter pins.
Once you've got your rig set up the way you want, use electric
tape to mark the turnbuckles. Saves a lot of time come next
season.
|
777.4 | Tension Guages make me tense! | CSSE::GARDINER | No more Monkeys! | Thu Mar 24 1988 13:48 | 29 |
| Re: Walt's comments on tension guages;
I bought one of these overpriced locker-liners and found it of
absolutely no use. When sailing becomes a science it takes away
from the objective.
Seriously, the tension guage gives a good indication of tension,
but does not locate the mast. Depending on the location of the
mast the loading on the shrouds will change underway. So the tension
guage must be used when on each tack with identical wind conditons.
This is not practical. In port it works fine, but when the keel
hits the water they will let you down.
Whne you have balanced the boat and KNOW that you stick is in the
right place, the tension guage would help set the tension on shrouds
for next season. Just before taking the boat out check your shroud
tension then back off eachturnbuckle the same number of turns to
get out the clevis pins. Don't forget to write all of this in the
log! When Spring comes around the sgrouds will have changed slightly
and the use of the tension guage will let get sailing faster.
I still suspect that sailors are victums of a conspiracy that makes
us buy everything marked MARINE! Regardless of its value.
Good luck,
Jeff
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777.5 | an effective lubricant | MSCSSE::BERENS | Alan Berens | Thu Mar 24 1988 14:27 | 32 |
| re .3:
>>> ... as long as the turnbuckles are well lubricated and you're
>>> sailing in moderate wind -- 10 to 14 knots -- adjust the weather
>>> side.
I beg to differ. This may be acceptable on a small daysailor, but
adjusting the windward turnbuckles, even if well lubricated, on a larger
boat is very likely to result in galled and damaged threads. I just
bought some new Navtec turnbuckles (for other reasons), and the price
was immoderate.
By the way, Navtec recommends a high-tech, high-price (something over
$15 for a large spray can), dry lubricant. Rod Stephens and I recommend
anhydrous lanolin, available at your local pharmacy (you may have to
special order) for under $10 for a one pound jar (which is a lifetime
supply). This stuff is extremely effective in preventing corrosion, is a
good lubricant, and is nice to your hands (it is normally used as a
cosmetic base). I've had no trouble with thread galling or corrosion,
and since our boat has rod rigging we can carry substantial tension in
the shrouds and stays. The stuff is also quite effective in preventing
corrosion between stainless steel screws or bolts threaded into
aluminum. It doesn't wash off, is biodegradeable, and is available from
natural renewable resources (sheep). What more could you ask?
Another easy way to readjust the rigging in the spring is to use an
inexpensive dial caliper (under $20) to measure the turnbuckle gaps once
you get the rig tuned to your satisfaction. The last two or three years
this has gotten the rig right with no fiddling.
Alan
|
777.6 | warning | CLT::FANEUF | | Thu Mar 24 1988 17:21 | 18 |
| A warning. Many builders specifically recommend you NOT use the
'tighten leeward' technique for tightening up your shrouds, because
of the great potential for seriously overtensioning them. I understand
some builders void the warranty on the mast and mast step (if any)
when this is done. This is particularly true of deck-stepped masts.
It might be prudent to check with the builder (if still extant)
if you want to use this technique. I'm sure you'd find lots of
variation between builders, but you just might ask what they recommend.
Note that Alan's micrometer technique can be used in 'leeward
tensioning' as well. You measure the amount you take up, tack, then
take up the new leeward side the same amount. Save adjusting a weather
turnbuckle.
Ross Faneuf
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777.7 | | GRAMPS::WCLARK | Walt Clark | Fri Mar 25 1988 16:58 | 21 |
| By the way I did not mean to suggest that tuning is limited to dockside
or must be done with tension gauges.
I always reset my rig to the place it was set the previous year
and tune from there by eye. I look for the things mentioned
previously (straightness, rake, bend) and tune accordingly (on
the leward side after tacking). I also lube my turnbuckles with
a dab of lanolin in the spring, I still cannot budge the weather
turnbuckle on the upper shroud under sail.
I think the tension gauges are useful for resetting a rig to a
predetermined (previously measured) setting, checking the more
complicated rigs (like whatever thay call that rig on Hunter's)
for even setup, and for determining that you either are or are not
tensioning a rig too close to the wire maximum. Most of these
things are pretty easy to do by feel if you have spent some time
doing them, but they can make someone unfamiliar with a new boat
more comfortable. I dont own one.
Walt
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777.8 | But what about the intermediates? ;) | DELNI::FACHON | | Mon Mar 28 1988 14:25 | 24 |
| re. "weather tuning"
Warning: If you've got such tension in your lower shrouds -- weather
or lee rail -- as to damage the threads on well maintained buckles,
then your rig is seriously overtensioned and the compression load
greatly increases your risk of rig failure. With that much
load on the lowers, just imagine how tight the uppers need be to
keep the mast in column -- even allowing for a little healthy fall-off.
Under most conditions, the tension in your windward lowers
should still be less than the tension in the uppers when the boat
is at rest.
Incidentally, nothing about rod rigging requires additional
tension over and above wire -- just the oposite. For a givien
tension, rod gives your rig better stability, and that's its beauty.
If your application requires uncompromised performance, you
might use added tension to better control your rig, but we're
talking about control that you won't even notice unless your flying
composites. For cruising, there's no reason to set rod up
any tighter than wire shrouds.
FYI Barient Barlube is also a terrific lubricant.
|
777.9 | Day Sailer Tuning | CSSE32::BLAISDELL | | Tue Mar 29 1988 09:57 | 53 |
| I owned and raced a Day Sailer I for years. Without knowing more about your
rig, the most I can say is that the Day Sailer rig is usually fairly loose,
the leeward shroud is always very slack underweigh, and the mast is usually
straight-up.
Some questions:
1. What kind of mast do you have? The Day Sailer was designed to have a
flexible mast (eg. Proctor Epsilon, Proctor Beta Minus), but O'Day and other
manufacturers switched to untapered Alspar and Dwyer sections to make the boat
less expensive. The new manufacturer (Precision) has gone back to tapered
sections and a lot of Day Sailer owners have upgraded their spars. The
flexible mast permits you to adjust sail shape with the boom vang and spreader
adjustments. The tapered top section falls off in gusts, help to keep the boat
level and going.
I suggest you adjust your shrouds at the dock. If you have a stock mast
you probably have pin adjusters and you certainly don't want to be
disconnecting them underweigh. It's also a good idea to do the adjustments
while tied up next to another (known to be fast) Day Sailer. Only at rest with
no one in the boat can you tell if the mast is straight up. Tied next to
another boat, you can compare mast rake (of course this may vary with
conditions).
2. Can you vary the rake of your mast? If you have rake ajustments, experiment
with it. If not, you mention that you have a tabernacle, and you can
experiment with rake by sailing with only the aft pin installed. Before I
upgraded masts, I sailed this way all the time, because the lower section of
the mast was not perfectly located?
3. Are your spreaders adjustable? Fore and aft, and length? These ajustments
have a major effect on sail shape and the stiffness of the rig. It is the
spreaders that control stiffness and mast bend more than anything else.
4. Do you have any kind of mechanical assist on your jib luff tension? Unless
you do, your jib luff sag will be too great. I suggest a Harken Magic box.
5. What kind of Day Sailer do you have? A DS I or DS II? The DS II had
undersized chainplates and you may wish to upgrade them. I don't know if
they're still in the business, but call Waggoner Industries, East Brunswick,
NJ about these.
6. What kind of boom vang to you have? Some kind of vang is essential, a high
mechanical advantage wire lever vang is better.
Most of the previous replies are interesting; but they apply to cruising and
offshore boats, not dinghies. I suspect the same about the article you read
and I suggest you may do better look at a dinghy racing and tuning book, like
SAIL's "Boat Tuning for Speed." The book focuses on 420s and FDs, but a lot of
the info is transferable to less sophisticated dinghies like the Day Sailer.
- Bob
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777.10 | | STUD::HEUSS | Forward into the past | Tue Mar 29 1988 14:30 | 50 |
| .-1 Thanks for the reply. I appreciate all of the other input,
but .9's right about the simplicity of the Daysailer rig vs. cruising
boats. My boat has only one shroud on each side of the mast and
no back stay, so tuning upper and lower shrouds is out of the question
:^)
>1. What kind of mast do you have?
I don't remember who the manufacturer of the spars is, but its in my
owner's manual. The boat is a Daysailer III (which I understand is not
really a Daysailer) and so it's whoever O'Day is using as a source.
The mast is aluminum with a mailsail luff rope track and is definately
tapered.
>2. Can you vary the rake of your mast? If you have rake ajustments, experiment
>with it. If not, you mention that you have a tabernacle, and you can
>experiment with rake by sailing with only the aft pin installed. Before I
>upgraded masts, I sailed this way all the time, because the lower section of
>the mast was not perfectly located?
The mast has a headstay, and single port and starboard shrouds.
The chainplates are mounted somewhat aft of the mast, so that gives
a three point support. About the only way to adjust the rake would
be to tighten up on the headstay, but that won't do much if I need
to rake the mast backwards. I would never have thought about not
installing the fore pin on the tabernacle. I'd be a bit worried
about insufficient support for the base of the mast, but I suppose
if its the only way to get the mast to rake back a bit...
>3. Are your spreaders adjustable?
No. They rotate about 45 degrees fore and aft, but once the mast
is stepped, they maintain only one position. They are also a fixed
length.
>4. Do you have any kind of mechanical assist on your jib luff tension?
The jib is on a roller furling rig. Luff tension can be adjusted by
hauling on the jib halyard, but that's it.
>6. What kind of boom vang to you have?
I don't, but the boom vang's offered as an option, and I may look
into one this year.
Thanks for all your help and suggestions.
|