Alternate Rigs.

Today I tried out a couple of sailplans I have been thinking about for some time. You can see photos because “one picture is worth a thousand words”

Both seemed to work OK. The hull is glass over balsa, just something I knocked up out of my head.
Forget the micky mouse waterproofing it was simply to try the rigs for balance today.

Two most interesting rigs Ian - that seem to more to address the core issues of Footy rig and hull design. Looking at it I am (almost) convinceed of the superiority of your Finn type rig over our Freedom type.

How well does the crab-claw sail on the other tack? Would a bifurcated A-frame mast be an improvement? Given that the rig does not have to be very tall, the CG penalty is not large.

Your thoughts?

Angus, the "crab- claw " sail does in fact have a “bifurcated A - frame” mast.

The attached photo may give a better view of that.

The original was with an ajustable tension top section, but I added some lightness and made it simpler by adopting a “preset optimum tension system.”:graduate:

The “Finn” type rig looks cool but getting the luff the right shape and attaching it to the mast is a difficult task.
I did have a pocket luff arrangment at one stage but that was even more difficult.
The full lenght battens pop through nicely and the sail has some shape built in.
We shall see if the theory works when I install some sail control and sail it properly.

I fitted the “Finn” rig to my trusty workhorse Bobabout design, “MuckingAbout” yesterday and went for a sail.
It sailed OK. :zbeer:
The winds were very light and shifty on the small pond which is my "other " venue.

There is more work to do before I am completely happy with the unarig concept, but it sure is easy to rig and sheet.:cool:

That look extremely nice!

looks good, how bendy is the rig?

I thought I might resurrect this thread to use for describing the making of the sails for the McCormack rigs.

These sails are so quick and easy to construct and require no fancy dohickies for broadseams or fancy corners or complicated luff curves or anything.

I have made them from Mylar, (old plan sheets) Ripstop spinnaker cloth, (offcuts from my friends at Linton Sails) Tyvek, ( paper like synthetic material ) Very lightweight spinnaker cloth (that I have forgotten the name of (oldtimers disease)) and even started to make them using composite construction ( fancy term for mixed materials.)

Having the correct sailmakers tape is a huge advantage as it is so quick and easy to use, sticks like crazy and is adheasive only without any carrier material making for finer joins.
Kikusui Tape is the brand I am using, purchased from Linton Sails.
I suggest you visit and make friends with your local sailmaker and purchase a roll of 10mm or 1/2 inch wide tape.
That will be enough to make sails for the next ten years.

Let`s make a sail.

  1. Lay your material on a flat surface with one straight edge facing you.
    Apply a strip of tape along that straight edge about 500mm long.

  2. Peel off the backing and carefully fold that edge over to form the pocket luff. Around 60mm at the bottom tapering to 30mm at the top.

  3. Place your mast section of 460mm length on to the boom and slide inside the luff pocket.
    Eyeball the angle of the boom over the sail material and mark the cutting line for the sail foot.

  4. Measure the foot length from the front edge of the sail (Luff )
    I am using 300mm.
    Cut the foot using a straight edge and a scalpel or razor blade or your favorite very sharp tool. (Domestic Warning: do not cut on the dining table or kitchen bench )

  5. Measure the luff length and mark, (450mm)
    Cut the head at the same angle as the foot.

  6. Choose a curve for your leech (trailing edge) which goes from the outer corner of the foot (clew) to the rear of the head. A 60mm head looks good
    That rear position is variable depending on your desire to have your sailplan looking like an ACC boat or not.
    Remember it is more difficult to have a large roach (rear curve ) set properly without some sort of battens fitted.

Thats it your done, let`s go sailing.

There is still plenty of room for experiments and improvements in this concept.
Full length battens, wing masts, double layer, multi panel and composite construction.
All will eventually be tried and reported on. In the mean time happy building. :zbeer:

I bought some bicycle spokes yesterday after a little research.

Seems they come in stainless in two thickness`s.
I purchased the thicker which was 14 gauge (wire gauge)

As mentioned elsewhere some thought is being put to developing the McCormack rig for larger craft.
Watch this space but don`t hold your breath.:lol:

I4 gauge is supposed to be 2.0 mm, whereas 13 gauge is 2.3 mm (the two most usual thicknesses) 15 and 16 gauge are 1.8 mm and 1.6 mm respectively.