Hi Peter and Clare,
Nosediving or sailing with a nose down attitude is a model yacht trait, it is just magnified in the Footy to an extreme because Footies are,… well extreme. It is just a function of leverage and the scale effect (compared to their full size sisters Footies sail in honey and gale force winds). I have concluded that there is not much one can do to resist diving so I have been pursuing design ideas to just let the boat do what it will. With practice (and a high bow and freeboard) a skipper can minimize the handling problems associated with downwind sailing, along with the choice of the correct rig for the conditions. (see the articles section on the Official Footy Website for my discussion of different hull-in-box placements).
And yes, my sails are paneled. Although a lot of homebuilders use a plain sail and force the camber (if any) into the sail by curving the sail’s leading edge against a straight mast these sails do not have the best shape for sailing upwind. It seems that twist off is easily mistaken for camber, they are not the same thing. With paneled sails one can control twist with leach tension and the camber that is cut into the sail (or airfoil section) can be varied with outhaul and downhaul adjustments. Now I have not yet tried to cut sails like Ian’s, using a large pocket to create an airfoil section, but his method looks promising. We’ll have to see.
As far a winch servo, you need to look for one that has a +50 oz./inch torque rating. I have used Bluebird 380MG servos the last couple of seasons. One did fail, but on inspection there was a small crack in the housing. I have now switched to the Bluebird 380MAX which has a higher torque rating for about the same gram weight. GWS and Raiden are two other companies (among many) that make servos with high torque ratings.
I also now employ a brake line for my rig. My winch servo failed when it was trying to hold the sail position on a run in high wind/gusty conditions. I now have my servo let out a bit more sheet than I need for the “all out” run and use a separate line from the deck to hold the correct position, thus taking the strain off the winch.
For a competitive boat, choosing and matching your electronics for performance and weight is important and can be confusing. Internet searches can turn up all sorts of intriguing components and the only way to know if they are appropriate for your boat is to try them or search the various r/c boat websites for commentary. For example, it is self defeating to use the lightest weight battery you can find coupled with servos that you have just lying around that are too heavy and underpowered. The weight loss provided by the battery is eaten up by the weight gain of the servo, giving you no advantage.
One strategy would be to use a removable r/c tray system with all your electronics aboard. You could have one board with a winch servo with lower torque for light winds and swap in a different (heavier/higher torque) one when the conditions warrant.
Keel depth and canting a bulb nose up are all topics that have been discussed at length on this forum. There are no concrete answers to the best way to set up a Footy, and that is what makes messing around with these little boats fun. It is pretty much impossible to design solutions to the vastly different pitch attitudes that these boats take sailing in just one direction, much less upwind, downwind, and reaches. Everything that one builds into their boat involves tradeoffs, and those tradeoffs are influenced by the particular environment that the designer sails in.
For example, for sailing in a location that experiences a short, steep chop one might opt for a shorter than maximum keel depth to reduce the tendency to hobbyhorse. This would not be helpful in a location that experiences wind that is higher off the water where a tall rig is the required, and hence a maximum depth keel for maximum righting moment. If a location has both these conditions then,… That is what makes it a boat race.
These boats, because of their size, are more prone to be influenced by different environmental factors like wind gradient and shear, as well as current and waves than the larger classes of r/c sailboats. And right now this class is still in its infancy so no one can really be deemed an expert. But if the spirit of cooperation that is key to the quick growth of the class so far prevails, and all of you out there reading these posts keep contributing your experiences and insights then the class and these little boats will continue to evolve in the most exciting ways.
