[Rhodes22-list] IMF - Art you forgot to say

Sat Feb 17 08:55:34 EST 2007

Art:

You forgot to say 'award winning':

http://www.manus.igus.com/testimonials.htm (scroll down until you see 9.9
motor)

Ed K
Greenville, SC, USA
Addendum:        “It ain't what you don't know that gets you into trouble.
It's what you know for sure that just ain't so.”  Mark Twain 

Arthur H. Czerwonky wrote:
> 
> Joe,
> 
> Why does a problem normally occur with the headsail furler?  I have
> usually found the problem at the fastening point on the mast.  I am going
> to help Luis with his this week.  
> 
> On the IMF it is better to reef on a port tack - look at potential
> friction with the sail slot and you see why.  Any other hangups I am aware
> of are based on preventative maintenance.  The internal workings of Stan's
> IMF are beautifully simple.
> 
> Art
> 
> -----Original Message-----
>>From: Joseph Hadzima <josef508 at yahoo.com>
>>Sent: Feb 17, 2007 11:08 AM
>>To: The Rhodes 22 mail list <rhodes22-list at rhodes22.org>
>>Subject: RE: [Rhodes22-list] IMF "Reefing"
>>
>>Hi Gang:
>>
>>I assume no one on this list has ever had any major
>>problems with their Rhodes IMF. Is there any special
>>maintence required?  I was on a boat where the furling on
>>the head sail failed as the 160 was fully out.  I recall it
>>was a little dicey going foward and fixing the problem,
>>under the no so calm conditions.
>>
>>the down side any time you add complexity to something, you
>>introduce another point of possible failure (plus
>>maintenance issues, cost, etc.).  I'm assuming Stan's
>>choice of materials, and his teams' workmanship minumize
>>risks, but I'd still like to know of any sea stories
>>involving IMF systems.
>>
>>
>>
>>
>>--- Jim Connolly <jbconnolly at comcast.net> wrote:
>>
>>> It seems to me that the difference between IMF and
>>> conventional from a
>>> weight distribution standpoint is two fold:
>>> 
>>> 1.  The furling tube which is negligible and the weight
>>> of the mast
>>> extrusion, heavier than standard.  Both of these are
>>> fixed weights (fixed
>>> height above deck with the mast raised in sailing
>>> position) and can be
>>> approximated by a weight "x" at the midpoint of the mast
>>> (i.e., center of
>>> gravity or CG).
>>> 
>>> 2.  The weight of the sail (less than conventional,
>>> because it is smaller).
>>> Since it reefs and furls on a vertical roller, the CG of
>>> the sail also stays
>>> at the same height above the deck.  The center of effort
>>> (CE) of the furling
>>> sail will move down and forward as the sail rolls into
>>> the mast.
>>> 
>>> Net effect, furling the IMF lowers the center of effort
>>> and not the center
>>> of gravity of the mast and sail combination, while
>>> furling the conventional
>>> sail lowers both the CG and CE.  The CG of the
>>> conventional mast/sail
>>> assembly is lowered by the weight of the sail, which is
>>> not likely a
>>> significant part of the whole.  
>>> 
>>> It seems then to come down to the additional weight of
>>> the IMF assembly with
>>> sail vs. the conventional mast and sail.  I don't know
>>> this, but I am sure
>>> somebody here does.  Likely windage of the thicker mast
>>> extrusion might be a
>>> factor in some wind conditions.
>>> 
>>> For me, convenience trumps all.
>>> 
>>> Jim Connolly
>>> s/v Inisheer
>>> '85 recycled '03 
>>> 
>>> -----Original Message-----
>>> From: rhodes22-list-bounces at rhodes22.org
>>> [mailto:rhodes22-list-bounces at rhodes22.org] On Behalf Of
>>> Bill Effros
>>> Sent: Saturday, February 17, 2007 9:55 AM
>>> To: The Rhodes 22 mail list
>>> Subject: [Rhodes22-list] IMF "Reefing"
>>> 
>>> Wally,
>>> 
>>> Comparing "reefing" on standard sails vs. IMF sails is
>>> very hard to do when
>>> discussing among sailors some of whom have never even
>>> seen an IMF.
>>> 
>>> "Reef Points" result in noticeable changes in sail size.
>>> The IMF is
>>> infinitely adjustable. I often adjust my sail in
>>> increments of 5% of total
>>> sail size. I suspect most IMF sailors change the size of
>>> their sails instead
>>> of using the traveler. We don't think of it as "reefing" 
>>> -- it is an adjustment the sailor can quickly make in
>>> response to changing
>>> conditions.
>>> 
>>> The extra weight of the mast is insignificant. Remember
>>> that your sail is
>>> larger, adding weight aloft compared to the smaller IMF
>>> sail. But, since the
>>> boat is designed to be sailed upright, and can easily be
>>> trimmed to sail
>>> upright, the difference in performance due to weight is
>>> probably no greater
>>> in an IMF boat than the difference of carrying an extra
>>> bottle of rum. Or
>>> not.
>>> 
>>> I carry my extra sail on the Genoa instead of the main
>>> sail. Both are
>>> infinitely adjustable while single handing. When
>>> conditions change, I change
>>> the set of my sails, all by myself, so easily that even a
>>> lazy sailor will
>>> do it.
>>> 
>>> I think the biggest surprise about the IMF is how well it
>>> works
>>> mechanically. The sail and mast are made for each other.
>>> There is no
>>> compromise here, and it is easy to extend and retract the
>>> sail under any
>>> conditions. My wife enjoys doing it.
>>> 
>>> Our harbor is busy on weekends with a very narrow neck,
>>> rocks all over the
>>> place, and a 10 foot tidal variation every 6 hours. It is
>>> irresponsible to
>>> sail into the harbor if you've got a motor, and most
>>> experienced larger boat
>>> sailors take their sails down just outside the neck, and
>>> motor to their
>>> moorings. We turn on the motor and don't even stop while
>>> we retract our
>>> sails. When my wife sees other wives trying to control
>>> flopping sails inside
>>> lazy jacks she shakes her head in disbelief. When other
>>> wives see my wife
>>> roll up our sail they ask their husbands why they don't
>>> have sails like
>>> ours.
>>> 
>>> Bill Effros
>>> 
>>> 
>>> 
>>> 
>>> 
>>> TN Rhodey wrote:
>>> > Bill,
>>> >
>>> > Well I may be wrong here .....I guess it would depend
>>> upon how much 
>>> > smaller the sail is verses the extra weight of mast.
>>> Way back when (on 
>>> > the sailnet list) there was discussion about this. In
>>> my opinion even 
>>> > if the mast weighed the same you still might need to
>>> reef sooner with 
>>> > IMF. Pure speculation on my part and I will admit I may
>>> be totally wrong.
>>> >
>>> > The R22 is small enough to be quite sensitive to subtle
>>> changes in 
>>> > weight and trim adjustments. You pay a price with IMF
>>> in mast weight, 
>>> > sail cut, no downhaul, no cunnungham, no battens
>>> (except for the new 
>>> > rev). If you know how to use all these controls you can
>>> create a much 
>>> > flatter sail. You would be surprised at the difference
>>> adding a vang 
>>> > made even with IMF. I could still flatten the sail
>>> enough to make a 
>>> > big difference ...sailing much flatter, fast, and
>>> higher into the wind.
>>> >
>>> > Everything is a trade off and for me the pros for IMF
>>> are well worth 
>>> > any cons.
>>> >
>>> >
>>> > Wally
>>> >
>>> >
>>> >> From: Bill Effros <bill at effros.com>
>>> >> Reply-To: The Rhodes 22 mail list
>>> <rhodes22-list at rhodes22.org>
>>> >> To: The Rhodes 22 mail list
>>> <rhodes22-list at rhodes22.org>
>>> >> Subject: Re: [Rhodes22-list] Harken Lazy Jack
>>> >> Date: Fri, 16 Feb 2007 09:02:30 -0500
>>> >>
>>> >> Wally,
>>> >>
>>> >> Why would a smaller sail need to reef sooner?
>>> >>
>>> >> Bill Effros
>>> >>
>>> >> TN Rhodey wrote:
>>> >>> Joe, There are some performance trade offs with IMF.
>>> The sail is 
>>> >>> smaller and I would think an IMF R22 would need to
>>> reef sooner but I 
>>> >>> am just guessing. That extra weight aloft must have
>>> some effect on 
>>> >>> balance.
>>> >>>
>>> >>> Wally
>>> >>>
>>> >>>> From: Joseph Hadzima <josef508 at yahoo.com>
>>> >>>> Reply-To: The Rhodes 22 mail list
>>> <rhodes22-list at rhodes22.org>
>>> >>>> To: The Rhodes 22 mail list
>>> <rhodes22-list at rhodes22.org>
>>> >>>> Subject: Re: [Rhodes22-list] Harken Lazy Jack
>>> >>>> Date: Thu, 15 Feb 2007 16:45:37 -0800 (PST)
>>> >>>>
>>> >>>> I've seen some other cool sail systems, some with
>>> sail covers so 
>>> >>>> you only need to zip it closed. Several replace the
>>> slot in the 
>>> >>>> main with a track system so even a kid could hoist
>>> the main, and it 
>>> 
>>=== message truncated ===
>>
>>
>>HADZ (a.k.a. joe)
>>
>>"That's what a ship is, you know. It's not just a keel and hull and a deck
and sails. That's what a ship needs. But what a ship is... is freedom." 
>>-- Captain Jack Sparrow
>>__________________________________________________
>>Use Rhodes22-list at rhodes22.org, Help? www.rhodes22.org/list
> 
> __________________________________________________
> Use Rhodes22-list at rhodes22.org, Help? www.rhodes22.org/list
> 
> 

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