F100 Ideas

Posted by: lorsail on Sep. 23 2002,14:41

Well, since I just posted this on the "old" forum and just found out about the new one today this is an update of the old posting--and a test.
 The Formula100 Class is one of the newest classes and certainly has the most up to date and progressive rules. The rules will be posted here somewhere when I find out how to and where to...In the meantime info can be found at < http://www.formula100.org >
The following is a description of a design I'm working on called "microMOTH" inspired by the full size Moth. This model has a narrow 4"(101.6mm) beam and is one meter LOA. The central design possibility in this class is that it allows movable ballast and that includes canting keels , water ballast, and a sliding rack type of on-deck Power Ballast System.
My proposed configuration is a canting keel with about 2.5lbs.(1.14kg.) of lead in a bulb
hanging on a canting keel strut and a sliding rack controlled by the same Guyatt winch that controls the keel. The rack allows the boat to
fit within the rules when the ballast is neutral but when the ballast is extended outboard the lead in the keel moves out (from zero degrees) about
1-1.17'(304-355mm) and the lead in the rack(2lbs.-.9kg) about
1.3'-1.5'(396-457mm).
 This allows a righting moment at 10 degrees angle of heel comparable to an IOM at about 45 degrees angle of heel. Which is enough to allow the F100 to carry around 1200sq.inches(.77 square meter) of sail in the same conditions an IOM carries its top suit: that is about 36% more sail area on a boat with a 6lb.(2.7kg) all up displacement. So compared to a "generic" IOM the F100 in this configuration would have 36% more sail area ,over 25%less weight and over twice(200%) the righting moment at a 10 degree angle of heel.
 So the cool thing is this would be one of the most powerful one meter models ever ;the downside is that ,like the full size Moth, it would be difficult to learn to sail especially in puffy conditions. But who said extreme speed has to be easy?
Hydrofoils, one on the rudder and one on the daggerboard (just ahead of the keel strut) would dramatically improve handling in windier conditions.
And in lite conditions, since the F100 class is specifically ditching RRS- rule 51, ballast can be removed between races so in lite air this boat could sail with 1200sq. inches of SA at an all up weight of 4lbs(1.82kg.)!! Less than half that of an IOM...
So whaddya think??
NOTE: See update(1/11/03) on microMOTH and different configuration for first boat--eliminates canting keel

Posted by: Guillaume on Oct. 08 2002,04:45

Hi Doug!
Seem very interesting, and it feets so much with the Formula100 spirit!
I think  that the boat could be very fast during "runs" with well established wind.
My only fear is that it will be hard to control in moderate/changing air conditions during a regatta, which is, on my mind, sufficient for loosing a race?
Maybe more targeted for speed runs that for real race?
Anyway, it's a very exciting project!

Posted by: lorsail on Oct. 08 2002,07:04

Hello, Guillaume! as one of the founders of this class in France it is all your fault that I have dreamed up this monster!
 I think that this boat will be very difficult to sail for someone with no  movable ballast experience especially on-deck movable ballast. But having experimented with this system a lot I know it can be mastered. Sort of like the first time you get on a Windsurfer--real difficult but practice improves performance.
 Conceptually, this is definitely on the thin edge of practicality but when it is mastered will reward it's skipper with astonishing speed...

Posted by: Guillaume on Oct. 08 2002,11:46

There is also another aspect in the "control" of the boat during a race. You have to study the whole race area for looking at the position of the others boats, and for watching  the wind evolutions. This require that your boat can be stable enough to continue going fast on its own while your eyes are not focused on it.
I am actually working on a canting keel for my next Formula100, this require a third channel, and I am still not convinced that the speed advantage is enough for winning in changing airs against a boat easier to sail without keeping the eyes on it continuously.

Some M sailors have tested a third channel for mainsail or mast control, and went back to two channels, finally more simple and efficient.

Anyway, the fun and the answers will be on the water...

Posted by: lorsail on Oct. 08 2002,13:33

Guilluame, movable ballast is easy to get used to and a whole lot more fun than sailing without it! If you design a canting keel boat with the ballast all in the keel instead of partly on deck then your boat will be very easy to sail; adding a portion of the weight to a sliding rack system on deck makes it more difficult but gives you the option to easily remove/add weight between races.
 How much ballast will you use in your boat and how far will you move it side to side? Any other details of your boat would be interesting!
Good Luck!

Posted by: lorsail on Jan. 11 2003,11:47

I am building a 37.5" (including outboard rudder) boat that for now will be called the microMoth( see initial posting or thereabouts on this thread: 1st incarnation of microMoth was to have a canting keel as well).
It is designed to test the premise that a high performance rc monohull can be built utilizing hydrofoils in all conditions (emphasizing winds from 5mph up)-one on the fin and one on the rudder with absolutely no ballast in a bulb on the fin.
Stability would be created by utilizing a sliding rack type of Power Ballast System that is much less expensive than a canting keel. The rack itself has small rectangular buoyancy pods on it so the boat won't just roll over when it is put in the water. This initial model is using a single Wing Tip main that is reefable and is designed to get up on foils in as little as 4- 5mph of wind.
 This thing is highly experimental and will be difficult to master. Once on foils, theoretically, the boat should be relatively easy to keep balanced since the guys that sail full size Moths on foils  and David Lugg who sails an I14 on just two foils all say that balance is not a problem.
This hull is 36" loa with  a 1.5" outboard rudder and has a 4" beam. The sliding rack is 26" long and the whole rack slides side to side. All up weight will be around 6lbs though the boat should be able to sail with as little as 1.5lb.'s on board for a 4.5 lb displacement in lighter air.
 The real difficulty with this boat will probably be in getting started--just prior to rising up on the foils and I will experiment with a rc helicopter heading hold gyro to help smooth out the balance early in the take off process. Initially ,the flap on the main foil will control altitude thru input from the skipper but an easier to fly version might use an altitude control system similar to Dr. Sam Bradfield's that I use on the F3.
If this concept works at this size it can possibly be  scaled up to the F100 class though because of beam restrictions  the buoyancy pods would have to be changed and the rack shortened substantially. One step at a time...

Posted by: lorsail on Feb. 06 2003,07:55

In working on the boat in the previous post and on the aeroSKIFF I've found a simple solution for those that might be interested in sailing in the F100 Class-the most advanced rc monohull development class ever!
 Using a sliding rack system made of carbon tubes with a weight sliding across the boat and powered by a single Guyatt winch is a simple way anybody can convert a 36/600 or US One Meter to an effective movable ballast boat. This allows a significant portion of the weight in the bulb to be removed (over half) and replaced in a ballast cart on deck sliding on the rack. This allows weight to be varied between races easily and allows the boat to be configured for the conditions it is sailing in. You don't have to carry around excess weight in lite conditions and you can easily add weight in stronger conditions.
 Having a small amount of weight in the bulb allows the boat to be easy to get used to but still challenging ; almost nothing beats the feeling of having fingertip control of your boats' stability!
 A system like this can be added with no modifications at all to a hull and minor mods to the deck. So take a look at the rules and give it a shot...

Posted by: lorsail on Feb. 07 2003,09:04

microMOTH first testing should be within two weeks of now--God willing and the creek don't rise.
This boat uses a longer rack than the inexpensive F100 in the last post but the system works on the same general principle except that the microMOTH has zero ballast in a  bulb and will probably be very difficult to sail...

Posted by: lorsail on Feb. 07 2003,10:06

The priority for the next few weeks is the 16'Dancer but along with that the microMOTH/ 36/600 spin  boat mold is complete with the mast step mold and boom mold plugs just completed. While I'm waiting on some technical problems to be resolved on the aeroSKIFF I'm gong to test sail the microMOTH using the aeroSKIFF foils which are interchangeable. The microMOTH uses a longer version of the same exact sliding rack system that will be used to make an inexpensive F100 so when it is tested it will be the same as testing the F100 system. The 36/600 and X3 F48 multihull are next in line after the microMOTH but the tooling is mostly interrelated for all the small boats and the F48 tooling is 100% complete so there will be a "blossoming" of boats coming out of here for the next while......
The 16' Dancer is three quarters complete and will free up a lot of time until something breaks!
This is full time effort to develop a series of small high tech boats from 42" down and I'm making excellent progress in solving problems and getting the electro mechanical parts right.
Many pictures to come!

Posted by: lorsail on Feb. 07 2003,18:09

The F100 class will be home to many ideas but see my 2/6/03 post for one of the simplest and least expensive ideas I've yet come up with to convert an existing hull or a new one, for that matter, to a powerful and fast movable ballast boat.
The 2/6/03 post is a description of an idea that has grown out of other recent work I've done. It allows the conversion of almost ANY boat simply and relatively inexpensively to a movable ballast boat. It allows anyone with intermediate building skills to do this on their own without buying one of the few existing production boats of this type--and this section of the forum provides all the info on the Formula 100 class that you could need to build or convert a boat to race within that class.
Putting the speed aside for a minute: I haven't talked enough about the fun of sailing these boats. I've sailed and raced quite a few of the existing classes and have had fun doing it. But no other monohull experience compares to the feeling of having the stability of your boat at your finger tips! Man, this is really serious blast out fun and is available to anybody at the cost of one winch and a few small parts. I can tell you that sailing and especially racing these boats  is the most fun you can have in rc sailing! (without a spinnaker or more than one hull!)
And movable ballast sailing especially within the F100 class is something you can do yourself without having to purchase a boat from anybody--just a Guyatt winch from Great Basin or direct from Guyatt, a couple of small carbon tubes  and you are in for one of the great rc sailing experiences.
I've experimented with these types of boats for years but recently I have been privileged to test sail two different types of movable ballast boats and that has really jacked up my enthusiasm level. I'm willing to consult for free or help in any way I can if you're interested in this new way to race and sail......

Posted by: lorsail on Feb. 23 2003,16:46

For those looking at the Formula 100 for the first time  please note that there is a 13" beam restriction but that does NOT apply to the Power Ballast System as long as a canting keel or sliding on deck rack is within 13" when in neutral (centered).