I just finished the sails on my first footy, and as soon as the ice melts around here , she will be in the water for sea trials.I copied a Mccormick style rig, but the jib seams to bind in its swing when it crosses over center. any help would be appreciated.
Welcome, Jim, to Footydom.
Brett’s original design for that rig was intended as a conventional rig that was easy to change. The front spar was pinned to the bow so that the rig did not swing.
Your jib pivot is clever, but I would replace it with line, which would allow the jib to pivot freely and lift a bit if necessary as it swings. It looks like your pivot is rigid, and keeps the jib boom in a horizontal plane. I think that might be prone to binding because the force of the wind will put some upward pressure on the boom. I’m guessing, I admit, but it would be a simple change to try.
Hi Jim K - You have a nicely crafted hull there. You obviously have the chops to construct a top notch Footy.
My input would be that you have chosen spars that are way over spec. You should take a look at the equilibrium rig down under thread to get an idea of the spar size that is more appropriate to Footy size loads. The rigging should be as light as possible to do the job. I would think that the hefty metal fitting on your main boom would weigh about a third of the weight of a McRig.
Bill’s suggestion of substituting a string for your nicely machined jib pivot is a good one, and may help to get you on your way right off. It may be just for photography but your rig looks pretty tight. Getting the various tensions in the sails in balance is an art that takes quite a long time to master. Generally speaking it is better to start out with the sail’s controls fairly loose and gradually tighten up on individual controls until everything is looking right and pulling well.
The sails look nicely made but in the photographs look like they are pretty stiff. Sail material for Footies needs to be lightweight and responsive with limited amount of stretch. Folding over the sail material on the leach is really unnecessary at this scale and will interfere with the sail’s reaction time and it’s ability to twist. Twist in Footy sails is important to attach flow to the sails because Footies operate entirely in the boundary between disturbed wind off the water surface and the wind that is above that is trying to straighten out.
Please don’t take these critiques as criticism, they are meant to advance you along the learning curve. Judging from the photographs I don’t think you should have any problems constructing a new rig. If you do build a new one don’t scrap the old one, it would probably be helpful to you to be able to compare the two later.
Thanks guys for your input, the string pivot is an excellent idea and will be corrected , the sail plan that was copied , it showed a metal rod that slipped into the leach of the jib. I will build a new sail that eliminates the fold and look for a smaller spar & boom material.the sail material is .003" drafting mylar that is waterproof , but seems quite flexible without stretching . I admit that after reading about swing rigs, I may have mistakenly intermixed the swing rig into a standard sloop boom on the main sail.
Hi Jim - I kind of guessed that you used drafting mylar for sails. This film is way too stiff for Footy sails, except maybe for storm sails. A lot of guys use TriSpi 25 from Hang-Em-High Fabrics (a kite materials supplier).
Mylar for sails should be 1.5 mil or 2 mil at most. It is out there, its usually used in the printing trade so it is mostly available in industrial rolls, way too much for a hobbyist. You might be able to get small amounts from a commercial printer if you ask nicely.
Tetra’s first float, with servo installed, standard Spektrum receiver and 4 AA drycell batteries, 185gram bulb. I was surprised with how little wetted surface there was and I can still move batteries fore and aft 2" for better trim. the light air sail rig was made from a light weight rain poncho and solid and tube aluminum. flexible boom mount is small bungee cord glued top and bottom.I wish that this was adjustable some how.