it is somewhat trapezoidal shaped…but its only about an inch shorter at the head of the sail. so it’s not much. I also figured better to build the gaff and boom longer, such that I have the option for a smaller narrower or more trapezoidal shape in the future. if I went small early, then I have no way to easily go larger… without building a new rig…
will the round mast cause windage…yes… but the leading edge of the sail is in the clean air… I’m sure a few pieces of 1/64 birch and some sail tape I could make an “airfoil” sleeve to cover the mast…
the gaff cannot pivot or rotate. but it is of a lighter carbon than the mast/boom so it does have some give…
initially I might use a thin hard wire for my forestay, something that I remove easily and adjust fore and aft and also make it easy to slide on/off a new sail… so the luff will have a pocket(at least initially) for the forestay.
it you lok at the pic you’ll the red line is the forestay and i’d drill a hole in the gaff and boom and bend a hook in the upper portion of the head stay so the wire will “hang” on the gaff and pass through a second hole in the boom to keep it in place. and then use some spectra at the head to keep the sail from wanting to slide down the wire…
to prevent the bagging i had given some thought to putting a leech pocket see upper picture below for the back stay to go through., this would eliminate bagging altogether. something i noticed on Andy T’s rig while it was sailing… but it would require that the backstay be able to slide along the gaff and the boom to allow sail shape and maintaining tension…this would begin to create a nice wing shape with a “solid” trailing edge. and clean leading edge… provided both wires are firm enough to not bag out…
Yes bagging is a problem that i encountered with my Hoyt rig, however this may have been due to my inexperiebnce with panneling.
Hindsight would have allowed me a shorter luff so i could have increased the tension a trapezium with the leech and luff being parallel would have been ideal.
Rgds
AndyT
I tried to make oneof those mast sleeves. It wasn’t easy. What I did was to fold some rdafting mylar over a mast tube (6mm carbon tube) and glue the aft edge together. That doesn’t seem to be the way to do it because while it was a kind of teardrop shape, it was too tight to spin on the mast easily. I think maybe the hetter way to form the sleeve would be to just make a tube bigger than thte mast and crease what would be the trailing edge. perhaps a little heat will help there.
My offsets are 35mm the sleve is 25mm to the end; maybe just too small?
I already had that idea, but to just use heat to reshape the sleeve I have. That’s if I can get into the barn after digging out the door, for the heat gun. :scared:
I’ll try it, but It’s not that important yet because there’s no way to slip the sleeve on the mast wth the offset arms attached. I ill work on it some more.
I’m wondering what test results people have had with the Hoyt rigs? John W made one, and it sailed great on one tack, and miserably on the other. It seemed more learning was needed, or the rig was fatally flawed at such small scale.
Assuming you actually got a rig built, what would use for a bearing at the bottom? I was thinking of a metal pin (or small bolt) glued into the mast base and a steel ball at the bottom of the mast step/tube.
In rather larger boats I have used a spring loaded door catch, mainly because the housing was a neat fit into the base of the Dural mast. A single ball bearing of a size to fit the bottom of the mast tube gives an almost frictionless bearing. In footy size a dome hear screw in the base of the mast and a ball in the base of the mast tube would do the same.
At the loads a footy mast generates a free standing rig (Swing Rig, McRig, or Hoyt rig) can pivot around a s/s pin extension from the mast base into a tube in the deck. I find that 3/32" diameter is a good size for the pin. I round off the lower point of the pin to a hemisphere shape (simulating a ball bearing). My mast tubes are 1/8" o.d. brass tube with an .025 brass plate soldered at the base as a stop and bearing plate. This brass tube is just a little larger interior diameter than the pin’s width, so the rig swings easily with just a bit of slop. With my swing rigs on larger classes I allow some slop in the rig/hull interface to reduce the amount of surface contact between the bearing surfaces on the mast and mast trunk.
I also have some s/s rivets that match the inside diameter of a 3/16" pultruded carbon tube (mast stock). These were intended to be the bearing at the base of these carbon tube masts. I haven’t used them though because the s/s pin seems to work very well and the mast tubes are lower volume and lighter than the mast tubes I cast in carbon fiber to accept a carbon mast. Lower volume is important in this class, especially when you use multiple tubes to have alternate mast location options, because the mast tubes that aren’t in use can fill with water in rough weather. When every gram counts carrying water in your mast tubes adds weight so small diameter mast tubes are a plus.
Hey, for all of you about to suggest that I tape over the ones that I am not using let me just say that I’ve had “what-was-advertised-as-waterproof-tape” peel off in inclement conditions and foul my mast. I don’t trust any tape to stay put outdoors. So, go ahead and tape over any holes in your boat, I wish you better luck than mine.
I must admit that I also have not used a bearing ~ I just use a pipe cutter on the ali tubes and then slide one in the other. The way the pipe cutter indents the pipe allows one to surface to slide on the other and when the tip is treated with a small dab of silicone grease - seems to work for me but I can see some benefits so the next one will change ~ I have got some small plastic fishing beads that will do the job nicely
Having that longer forward spar should allow you to move the CE of the sails forward some; did it work? You could end up with a somewhat large gap, no?
Are you sure that the boat isn’t just rocking? Remember that it’s probably not a boat with a long heavy keel like our models. From my experience, something that size probably has a weighted swing keel, and I’ve never seen a sailboat in a slip that wasn’t rocking.
Tommo, the shaped brass rod is a nice touch, I might have to plagiarize that
I have not done anything with my 507 for ages - i was in the process of putting a new deck on it when i got a split in the hull. The plastic seems to have become very brittle. Andrew Cook was good enough to send another hull over but I have not got round to making it up yet.
I am however going to put a third position on FootyCat so that she can either have a Brent style Z wire swing rig or the Bi-McRig
