Details of the SunCat drifter modification

[FireDrill]

In addition to posting in the SunCat sub-forum, a similar version has also been posted in Boat and Hardware Modifications  because the addition of a drifter, set flying, with hardware mods that provide setting and dousing control from the cockpit has wide applicability to all ComPac sailors.

As pointed out by Capt_Nemo, a simple  38 square foot nylon drifter makes sailing a SunCat (or many other boats)  in light air easy when the main sail alone results in very little or no boat speed.  (see "A drifter for light air is highly recommended"  in SunCat  Sub-forum)    I followed most of Capt_Nemo's helpful dimensions (7' x 11'x 12.5'  foot-luff-leech),  suggestions and rigging details. Sometimes during the hot summer days, the wind dies during the middle of the day so I wanted to be able to set and douse the drifter from the cockpit during a sail.  Here are some rigging details See pictures on page 2, 3 and 4(page 1-not shown -  and  2 are on my original posting about performance) :

       





The halyard is managed by a small Ronstan C-cleat on the port aft cabin top, fed through the original fairlead to a bullet block on the port side of the mast stem and then up to the top .  The halyard's top cheek block is attached to the front of the mast,  just under the forestay hound.  I keep the halyard snap shackle  attached to a short lanyard attached to the forward lazy jack eyestrap on the boom. (Note, a  cabin top mounting would prevent  tacking.)    This is switched at raising time to the head cringle.  The tack is managed by a downhaul through a block on the aft anchor roller bail. (see photo on p 4) This is secured after passing through the same fairlead to a 4 inch nylon cleat on the cabin top. The tack snap shackle is stored over the aft end of any of the cleats on the cabin top before being snapped to the tack cringle. .  I keep the sheets, rigged outside the shrouds, secured  through the midship-cleat-mounted-cam-cleat arrangements (Nemo design) ,   but also attached by a snap-shackle at its center to an eye-strap on the forward end of the port cabin top slider rail. When raising the drifter,  I switch the snap shackle to the clew cringle.
   
I hoist the halyard till the head shackle knot reaches the cheek block.  Then I tension the downhaul which can be adjusted along with the halyard to set sail height.   Finally I cleat the appropriate sheet to set the sail for the proper heading. Note that I use the original fairlead for 3 lines which Capt_Nemo had suggested as possible. (It works well!)
   
I keep the sail on the cabin top in an old small sail bag tied to the port handrail.  It is stuffed into the bag  so that the head, tack and clew  cringles are at the top,  To raise the sail I attach the three snap shackles to their respective cringles , raise the head fairly far up with the halyard, then set the downhaul, adjust the tension between them and then set the sheet to the appropriate side. Dousing it,  I release the halyard and grab the leach as it falls, stuffing it in the bag first.  Then the other lines are released and the stuffing finished.

The drifter itself  was made of  ¾ oz nylon from the top of a ripped spinnaker (which I already had)  cut down by Haarstick Sails  to Nemo's 38 sq ft drifter dimensions (foot=7',luff = 11',leech=12.5').  It cost me $180 for the sail-maker labor and about $150 for the hardware and new lines.

Three new cleats are  screwed to a teak block on the cabin top, See photos on p3.  I elected attaching the teak block to the cabin using  long horizontal  wood screws (#14), one  through the downhaul cleat opening  and two others through the teak block into the cabin top wooden slide rails. All are angled slightly downward.   While not as strong as bolting through the cabin top directly with a backing plate,  the loads on these cleats in light winds should be small, and largely horizontal,  so I believe the mounting is sufficiently strong.   As you can see, I was not able to do precise drilling with hand tools (using 12 inch bit to get a good angle with the fat hand drill) in the field where I store my boat (ugh!) A rubber pad was cut and screwed to the base of the block to prevent scratching the cabin top , reject water pooling and provide some small compression against the screws.

The various cleats are indicated by arrows on the page 3 photos.  I used Ronstan Small C-cleats for the major lines (halyard and sheets)  and 4 inch nylon West Marine cleats for the other two on the teak block.    I will Cetol the wood blocks; they are shown here unvarnished. The halyard is led, from a small single swivel bullet  turning block (recently changed to a Harken bullet block)  on the mast stub to a Ronstan series 29 cheek block below the forestay tang. The snap shackles are all small  Ronstan Keypin Locking Halyard Shackles.   The mainsail (boom) downhaul line is shifted from the original through-cabin-top cleat (now used for the anchoring rode)  to the forward 4" cleat on the teak block. Since I usually sail with the boom above the long pin, this downhaul is not heavily used and can be switched back if needed.

Thanks are in order  to Haarstick Sails – Rochester - for excellent workmanship in creating the actual sail from an old ripped spinnaker and for your design and all your help Capt_Nemo!!!   
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[capt_nemo]

FireDrill,

You're quite welcome indeed.

Very WELL DONE on the detailed post with photo diagrams.

capt_nemo