[Rhodes22-list] Jammed IMF:(

[Theodore Boender]

Stan, I am sure it is operator error, my fault. I'll chalk it up to my rookie status. I will ensure the boom is low as possible with a slight angle to starboard. I'll investigate further this week and report back. 

Good to see you back on the list. I truly appreciate your support and passion. 

Take care,
Ted

 





On May 12, 2013, at 10:39 AM, Stan Spitzer <stan at rhodes22.com> wrote:

> 
> OK, I suppose I have to run aground more often to have the time to 
> respond to some of your occasional S.O.S. signals.
> 
> The IMF never jams at boat shows, where it gets more use in less than a 
> week than most of you give it in a lifetime.  It does not jam on 
> demonstrations or rentals or even when//*I* go sailing which admittedly 
> has not been for several months now.  And there are owners out there who 
> have never figured out how to jam their IMFs.
> 
> Why is that.
> 
> It is absolutely a fool proof piece of equipment because it has no 
> springs or gears and merely floats freely in a chamber.  (Well, maybe 
> "fool" proof is a poor choice of words since I know that most of you who 
> jammed your IMF are normally brilliant,)
> 
> There are only three reasons for an IMF system to refuse your bidding:  
> Mechanical.  Human.  And all others.
> 
> Mechanical failure:  The sail may have ripped.  Or the sail may have 
> come loose from its connection at the top of its furling tube and 
> partially slid down its tube.  Or a bearing like the one atop the tube 
> may have come off.  That sort of rare stuff.
> 
> Human failure:  You may have caused a mechanical failure like putting a 
> curve in the mast by incorrect rigging or trailing with the mast up and 
> everyone understands how hard it would be to roll up a carpet on a "C" 
> shaped core. Or you may have forgotten to undue a cleat.  (This idiot 
> almost always forgets the vertical locking cam cleat on the aft 
> underside of the boom.)  Or you may be standing on the line on the 
> cockpit floor.  Or you may have turned emotional; a hammer or lots of 
> extra force only makes your Rhodes fight back.  Be kind and thoughtful.
> 
> What makes an IMF sail go inside its mast in a bunched up fashion:  
> Either your putting it away with the boom so high above horizontal that 
> more material than normal tries to wrap around the furling tube at the 
> same location;  visualize that carpet on the floor where you fold over 
> part of one side before staring to roll it up.  Or putting your IMF sail 
> away with the boat not pointed into the wind. Now you can put your IMF 
> main away in light airs with the boat in any direction relative to the 
> wind but in heavy winds, with the sail taking just the right beating as 
> it is being wrapped around the tube, it could be in a folded position at 
> that instant.   So, whenever you can, follow the prescribed way to put 
> away an IMF sail:  Boat pointed into the wind with the topping lift 
> supported horizontal boom having naturally moved itself slightly to 
> starboard of the boat's center line.  Sounds complicated but actually it 
> all can be automatic.  If you are not one who likes continual fussing 
> with sail shape, always sail with the topping lift supporting the boom 
> horizontally.  Then, when you want to put your sail away, do it as you 
> come about, just at that moment when the boom has moved itself to 
> starboard of the cockpit center line.  With all these stars in alignment 
> automatically, a pull on the furling line puts the main sail away in an 
> effortless instant.  Try it.  You will like it once you get your body 
> coordinated.
> 
> Reason for having the boom setting itself to be slightly to starboard:  
> The furling tube die (a proprietary GB extrusion for all you out there 
> who scoff at the Certificate of Support program) is designed for the 
> sail to wrap around it in a prescribed direction that both makes the 
> sail come out and go in easier because its wrapping direction is already 
> started by the tube's design and because that angle with the wind that 
> is established with the boom having moved to slightly starboard of 
> center, takes sail cloth pressure off the mast slot while it is emerging 
> from the mast, and conversely, when the cloth is going into the mast. 
> With the boat not into the wind, when in heavy winds, the cloth pressure 
> against the edge of the 26 foot long mast slot can get so huge as to 
> make it unreasonable to expect the sail to want to go back inside the 
> mast without complaining - or, for that matter, come out to sail ..
> 
> The Others:
> 
> Those weak on spacial relations might not consider that trying to pull 
> out a sail of cloth made not to stretch, cannot work if the boom is held 
> fast _below_ horizontal by the main sheet cleat. The explanation is so 
> simple that I can explain it.  The length of the back side of the sail 
> triangle cannot change. Lowering the aft end of the boom and holding it 
> there so it cannot rise means the sail length would have to increase to 
> fill this increasing space and that is impossible so the sail simply 
> stops coming out of the mast.  A good practice is for the boom to be 
> free and not locked down by the main sheet when taking out the IMF main.
> 
> If by chance a guest not attuned to all of the above common sense does 
> cause a sail jam it is easily corrected.  Not having had this problem I 
> learned its solution by seeing what the big boys with big In mast 
> furling did at boat shows.  They approached the mast, put two hands on 
> the sail cloth as close to the mast slot as reasonable and pulled the 
> sail material not out but /*straight down - */ The one place where force 
> is apparently not a no, no.
> 
> In conclusion a huckster remark:  If along the way of various owners, 
> someone has re-mounted the IMF main too high or too low on its IMF 
> furling tube, it will not work properly.  I will not go into explaining 
> this here but think of two fat ladies (or governors) trying to get 
> through a doorway at the same time.  If mounted too low the sail bottom 
> will be rubbing on the top of the boom slider and causing bunching - if 
> mounted too high the designed pulling out angle gets beyond its working 
> boundary causing the problem of the two fatties trying to go thru a 
> doorway.   As the sail comes out of the mast it should stay fairly 
> parallel to the boom with about an inch of continuous clearance. The cut 
> of the sail and its mounting on its furling tube are important to the 
> easy operation the IMF can provide under all conditions.
> 
> While early outhaul car systems will let you sail, the newer outhaul car 
> design (price C of S dependent) not only allows for better sail shape 
> through superior draft control, but keeps the sail bottom continuously 
> parallel to the boom and the boom much better in alignment with sail 
> direction, all of this allowing a broader range of orientation to put 
> the IMF sail in or out with greater grace.
> 
> there is probably something I forgot but have to get to my physical therapy.
> 
> ss
> 
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