Re: [Bulk] Re: [FootyUSA] Re: ideal footy displacement
- BernieI am returing to Vero on dec 1st,II will be brining Footy soling Micro magic, vic When are you sailing?I will likley not be on line this year, Last years bill was over 5ooo.$.I will likley go to cell. Save me awee bit offwarm weatherCharlieI ----- Original Message -----From: Bernie ceilleySent: Friday, September 25, 2009 10:43 PMSubject: [Bulk] Re: [FootyUSA] Re: ideal footy displacement
I agree with you, Bill. The HS-55 seems to be adequate for the rudder
but more power is definitely needed for the sail. I use an HS-82mg
for the sail. What do you use?
The HS-55, at 15-18 inch ounces of torque, barely can handle working a rudder, the size of sail that it could haul in reliably in any kind of breeze would likely be the size of a postage stamp. Saving weight is fine, but you still need to have the muscle to get the job done.
--- In FootyUSA@yahoogroup s.com, "LR" <lincolnr@.. .> wrote:
> I may be missing something, but it seems to me that footies as they exist are very heavy. If I understand correctly, the battery restriction is now gone, so it ought to be possible, with care, to build a very light footie. There is a ratio generally called the DL ratio, even though D/Lcubed would be more accurate. There's a neat calculator here:
> http://www.sailingu sa.info/cal_ _dl_ratio. htm
> Seems like most footies are close to a pound, or even heavier. One of the neat properties is that, for a footy with a one foot waterline, this ratio is very close to the weight in grams. So a typical footy might be 450. Now, we'd like fast boats, right? A J24 is around 180. A light US1M might be around 130 or so, although I guess some heavier boats are somewhat competitive at 150 or higher. To get a footy in that range you need to get it less than a third the displacement of a typical footy.
> I think this could be done if you used one of the new 2.4 gHz radios from an indoor flyer, and maybe an HS-55 (!) for the sheet, while using the built in linear servo for steering. It would be radically different, but I bet it could sail a LOT faster in many conditions.
> Maybe it would be worth it to go even lighter. I dunno.
> This probably wouldn't require any exotic materials, just thinking and care. At one foot I think the weight is probably going to be determined often by the lightest gauge materials available, rather than strength or even stiffness. (Ok, this is intuition as I haven't built one yet.) And those indoor planes are pretty cheap. The receiver is only $60 by itself, or you can get the whole thing with tx for $120 if you don't mind throwing the plane away. If you're really sneaky use the motor to make a hidden auxiliary, but don't tell anyone.
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- I have upgraded from the futaba 3115 to the futaba 3102 as well. metal gears enough torque...it is also the rudder servo for my footy, s1m, victoria, and odom. and I run a 2 cell lipo with no regulator with no burnouts yet...
I run a sloop rig