Rules driving design - inspired by Niel

Footy Class Rules and Helpful Hints
1

Just so you know, I’m new to this whole sailing business so I may make some strange statements sometimes. You can see the extent of my model sailing experience here.

Niel asked us to question the restrictions in the rules and how it might drive the future of the class. I also have some rules questions I’ve been saving. I don’t have enough experience to ponder the future of the class based on reading the rules.

  1. Niel, do you have a copy or link to the rules you built your Bantams for?

  2. Rule C3© - if the smaller set of sails cannot be more than 305mm above the box, does that mean that boats with short keels have a shorter limit than boats with long keels since thay will sit lower in the box? Assume vertical orientation in the box.

  3. Mast height - do I understand that there is not limit to the size of one set of sails used during a race?

  4. Rule G3© makes no sense to me. If sails #s 01,08,10,18,80 and 81 shall display a prefix ‘1’ and become 101,108,110,118,180 and 181, what happens to folks with those numbers?

Comments to Niel’s original post.

  1. Units don’t matter to me and should not be an issue. 305mm = 1 foot Use metric or convert to what you’re comfortable using. If you’re concerned about rounding errors affecting legality of your boat, err on the safe side.

  2. Now that the class is in the AMYA we have a mechanism to modify the rules. Before that, it was a few interested folks discussing things through whatever channels they chose. Propose a change and we’ll see where it goes.

2

Answered my own first question, I think. Is this the old Footy class rules that you used Niel? http://homepages.ihug.co.nz/~bsmack/rules.html

Both sets of rules seem to allow additional propulsion systems though. Or am I missing something that says “wind powered only”? Now where would I put the rocket assist pack? :wink:

3

With regard to your point 4 - sail numbers - the logic is as follows:

  1. You need large sail numbers on the sails if they are to be seen from any distance. Thus two large digits are better than three small digits.

  2. In most situations, the chance of a conflict between two digit numbers (eg 101 and 201 - both of whom show only “01” on their sails), is minimal at the same sailing location/event.

  3. When conflicts do arise, they can be solved by adding a temporary “1” as the first digit on one of the two boats. (I’m yet to see a three way conflict, but of course it could happen). Depending on the sail material, the “1” can be self-adhesive and removable, or applied with marking pen and removed with rubbing alcohol.

I hope this helps.

4

Thanks, Muzza. I just noticed something else. Those numbers are symetric and can be confused with each other when you don’t know if you looking normally or reversed (through the sail). The 3rd digit solves that problem. Hah, this sailing stuff makes more sense all the time.

5

Hi Tallastro, perfectly fine questions…as the old saying goes, the only stupid question is the one not asked!

To answer the questions that haven’t been yet:

Your item #2…Since the restriction is 305mm above the box, a boat with a shorter keel could have a longer mast. Of course that introduces the classic tradeoff between size of rig and righting moment generated by the length of the keel and bulb weight, so designers will have to figure out their optimal compromise. Although I hadn’t anticipated it, I suppose a boat that fits on a downward angle in the box could have a longer mast, also, but again the tradeoffs would come into play.

Your item #3…yes, you are correct that one of the two rigs is unrestricted.

Our thinking on this point was that we didn’t want to restrict innovation with regard to rigs, but we didn’t want the number of rigs to get out of hand, potentially forcing people to have multiple rigs to be competitive. By limiting the number of rigs to 2, and severely limiting the size of the storm rig, we think that designers will have to be reasonable about rig size decisions. If they go too big, and the boat is overpowered during the regatta, their only choice will be the small storm rig.

I’d also like to point out, as Brett has done previously, that the box rule is the first Footy rule officially recognized by any organization. The rules Niel refers to were posted by Brett a few years ago as a suggestion for creating international consistency for Footys, but they were never sanctioned by any organization.

When Brett (New Zealand) was approached by the MYA (England) to collaborate on a rule for their sanctioning, he suggested that I (USA) be included in the discussion. The result of the collaboration, which included feedback from a number of interested people, is the box rule that has now been sanctioned by the Footy Class Owners Association (established by the collaboration) the MYA, and now the AMYA. As part of the process of developing the rule, we published it on this forum, requesting feedback. Since there was minimal discussion, the rule was adopted.

Anyone interested, I suppose, can trace back the threads here and follow the discussion that occured, although a lot of discussion took place off the forum, as well. Looking back at Brett’s original suggestions, I think it may be worth noting that:

  • length is no longer restricted to 12 inches, depending on beam decisions and other design tradeoffs.
  • beam is now restricted, where Brett’s original concept had no restriction.
  • bowsprit length is no longer restricted.
  • although only 2 rigs (rather than 3) are allowed, the primary rig is no longer restricted.
  • keel depth, though restricted, can be greater than the original 8 inches, depending on hull draft.
  • standard servos are no longer required, allowing the use of mini/micro servos…or 1/4 scale, if you prefer.

All in all, my view is that the box rule allows greater freedom, not more restriction, than the original “rules”…but that’s only an opinion.

Bill H

6

Okay, the storm rig limitations may make sense if you build a boat that needs a diminutive rig to sail in real wind. But it does nothing to deter a guy from showing up at a regatta with a dozen rigs of various sizes and choosing the appropriate one based on the weather forecasts and local conditions. Serious competitors do that. There is no way to stop it or fashion a rule to prevent it. So as a strategy to keep costs down this concept will not help and may actually hurt the new-be that reads the rule and takes it literally. Unfortunately money wins races, just compete in a few International Championships in the M’s or IOMs and you’ll know what I mean. Example, technically the M class has only three suits measured, but you can bring any number of sails you want to a race (and sail with any one of them during a given heat) as long as the additional sails do not exceed the dimensions of the measured ones. I used to travel with a mere 7 rigs to out of town M class regattas. That was considered unprepared.

The idea that a diminutive storm rig will have any restraining influence on the other rig makes no sense for most of the US. Most racing sites on this continent would not see conditions that would warrant making this size rig. The original “proposed” rule allowed three rigs for use in a race. This makes more sense to me because the sizes would be tailored to the boat not to the expected conditions at a particular event.

Another restriction that does not make sense for the US is requiring the use of 4 AA batteries. Rechargeable individual AA batteries are being phased out. NiCads in this size are no longer available in commercial outlets here in New York like Radio Shack or Circuit City. You can only get them from online battery suppliers or catalog hobby outlets. Rechargeable individual AAs will soon be past tense though. They are being obsoleted by smaller more powerful AAA cells and battery packs like those that power cell phones (or my other model yachts). Now, I’ve read in previous threads that one of the reasons for the AA spec in the rules was because some older sailors don’t want to bother with rechargeables and the charging regimens that they require, but use alkaline cells instead and discard them after use. In the US non-rechargeable batteries have to be recycled which is a hassle and when you consider that a rechargeable NiCad or Ni-MH can be charged 100 to 150 times on average that adds up to the equivalent of a lot of alkaline cells per season, a lot of expense and waste in our landfills.

Technology will continue to march forward regardless of our wants or desires. The Footy class, being on the cutting edge of small, should embrace the trend towards miniaturization of electronics. If there is to be a restriction on our power source then I suggest that it should be defined in voltage (like 4.8 volts or the metric equivalent for example) rather than by battery type.

One last note. My comment about which measuring system Graham used to measure his boats was to illustrate that his statement regarding adherence to International Standards was not consistent with our national preference for the English measurement units. It was meant as a metaphor for the Footy rule. Not to be taken literally as a point of contention.

7

Which just goes to show how dangerous assumptions can be I guess :slight_smile:
Oh I wish that the US did prefer English measurements, then I could get a
decent amount of beer when I asked for a pint and a decent amount of petrol when I bought a gallon…

Yes I am pulling your leg Neil :slight_smile:

Graham (English expat.)

8

I like the 4.8 volt rule suggestion. I’m pretty entrenched in AA NiMH batteries for my electronics but a voltage rule might be more lasting and allow smaller power packs. We could even run a solar cell if the race site is sunny.

I’m not sure I understand the rig suggestion. The rule says you can have 2 rigs for an event. How does allowing for 3 rigs lower the number of possible rigs a skipper might have on hand? As it is, I have to pick my large rig based on forecast and course conditions with the storm rig as fallback. If I guess wrong and use too big a rig, I’m done for unless everyone needs their storm rigs. I don’t think we’ll see large numbers of different rigs hurting the class. Another thing these boats have in their favor is small cheap rigs. I could make up dozens and not break the bank.

Here’s a crazy idea. I could use a moderate size main rig and having a huge but short second rig if the winds are very light. If the wind gets too strong for my tall rig, I’m SOL. That’s racing, no?

9

There are “development” classes and “one-design” classes - everything in between is going to cause issues. It is difficult to maintain a “sort-of” type class, becuase you are going to need pages of rules/examples/dimensions and it will threaten to scare away a new sailor.

At the cost of these things (and their size) I wonder out-loud will cost escalation really be an issue? Will performance increase significantly when a hull is built from carbon versus fiberglass? Will two inches in mast height provide a dramatic and serious performance difference? Will AA batteries or AAA batteries, or “button” batteries, or solar panels impact the performance of the boat?

We (in the F-48 Class which is MUCH bigger physically than the Footy) went to great lengths to allow development of ideas and use of technology. Overall length, overall beam, maximum sail area is what is limited. Also kite sails - but that’s a different story altogether. We tried to stay away from rules that didn’t have a major effect on performance - and suggest the same for the Footy. If it - a rule - doesn’t affect speed - why deal with it - and why is it there? Do radio control classes REALLY need a rule saying an anchor isn’t necessary (an example) and PFD’s don’t have to be worn?

Just an observation and offered as a different point of view - you have a simple boat, with some good qualities - I suggest you don’t muck up the class with too many rules that require a day of measuring at a regatta to verify compliance. Just an opinion, I could be wrong.

10

Sticking the boat in a box seems simpler than even your multihull class Dick,not a tape mearsure in sight!!

To answer some of your other questions.
There is not a significant performance increase from moulding the hull in carbon as apposed to fiberglass.
I can build a 30-40gram bare hull shell in glass cloth and epoxy.I will stuggle to find carbon cloths light enough to do this,and even if I do find such cloths the extra stiffness of the hull won’t lead to a performance increase as the glass hulls do not deflect with slamming loads at all from what I can tell.

Batteries,the weight of the batteries plays a very important part of the Footy design contraints.4 AA cells come in at around 100g,you can find other batteries to do the job for as little as 30g.
since the batteries are fairly high up and the typical overall weight of a Footy is around 500g then you will see that battery weight plays a very important role in the ballast ratio and other design decisions.

11

“…battery weight plays a very important role in the ballast ratios and other design decisions.”, needlessly as far as the AA cells that are specified in the rule. Why are we required to carry an admitted extra 60 to 70 grams of weight to achieve 4.8 volts of power? Considering that Footies are already tender to begin with this is idea is particularly ill advised. These threads have been touting an ideal weight for a Footy to be in the 450 gram to 500 gram range all up. Carting about 70 grams of destabilizing ballast plays very important role in depriving a Footy of optimum righting moment and therefore upwind performance.
So. are we talking about batteries here or are we discovering a backdoor means of implementing a minimum weight rule for Footies? Obviously, the lighter that someone can build a boat (isn’t that why everyone out there seems to be using balsa and foam) to achieve the lighter displacement target numbers, the more that extra battery weight will become counter productive to the effort, needlessly.

12

So what do you propose? Changing the rule to 4.8V with no weight restriction on power pack? I’d like to know the cost of alternate 4.8V solutions. Any info on mAh or running time would be cool too.

The 4AA rule could level the field in an area that might be expensive or unavailable to some skippers, like kids. It also keeps the power pack simple. Some of us, like me, just plain like AAs so I guess I “need” them. :rolleyes: I remember your post about AAs being retired, do you have sources for that news? I use AA NiMH because they hold a charge well, provide ample voltage till discharged and, best of all, if I don’t have any charged, I can buy alkalines to tide me over. Proprietary rechargables are often expensive and cannot be purchased at the local corner store. And even if you can find that oddball battery at a store, it’s not charged. Rechargables also like to be charged regularly. A battery that doesn’t get used much will have poor performance. How often will a Footy get used?

As far a materials, I used balsa because it’s cheap, available, and easy to work. I’m new to scratch model building but it can’t get much easier than paper thin balsa and super glue. I’d like to get better at finishing the hull. I’m not very good with putty, sandpaper and paint yet. Mine’s lumpier than I’d like but I’m pushing production to get it in the water. The next will be more relaxed and have better fit & finish. Depending on what my final costs and performance are for this first build, I may buy a Hang Ten next time too.

Since I’m thinking of performance, had anyone raced Footies head to head yet? Some of these design questions could be answered real quick if a certain design is real slow.

13

I?m not a footy sailor, but it?s pretty obvious to me, that this rule is designed to keep costs down. If a rule of this type was not in place, People could use 25-45g lipo packs, and put an extra 60-70g of lead in the bulb.

14

OK, but how much does a LiPo system (battery & charger) cost to somebody like a cub scout?

15

Tom,

I said most likely this rule is in place to keep costs down. So having this rule is keeping people from using Lipo?s, thus keeping the class within reach of cub scouts. This is a good thing in my opinion.

16

Exactly, Niel. Balsa is great for kids, so I advocate that. I’m always looking for alternatives, like the foam plates you get your steak/meat on (at least in the U.S.) but it looks like only the supermarkets ge that in quantity, and you probably won’t see any in the local hobby/craft store or DIY. I’m there doing some “shoping,” so…:rolleyes:

I’ll bet there’s some Cub Scout outs there that are flying with LiPo batteries, but I’ll also bet Dad is doing the battery maintenence, until our little fella gets handy with the equipment.

17

Since I’m thinking of performance, had anyone raced Footies head to head yet?

You bet we have,been racing them for some years now,as well as some friends of mine in the UK of who have been having regular weekly racing for some years now.
I personally have tried about 10 hull designs,varying the parameters of beam /draft and displacment.
I think I have a pretty good handle on what is going on design wise with these little boats.

18

Remember that the Footy has been around for many years now, not just thte last one or two that we’ve been discussing it here.

Brett–

Do you find that the area around a mark seems as crowded as the bigger boats, like 1M?

cheers,

19

Since we are looking for 4.8v I would like to mention that LiPo cells cannot give you 4.8v. Also there are some safety issues with LiPo cells as most of us will have read in the electric aircraft forums or elsewhere. If I remember rightly LiPo’s are actively discouraged if not banned at some UK boating events/venues?

I use alkalines, usually Duracell and so far this summer, sailing twice a week for at least two hours at a time I haven’t had to change my batteries yet… I really like not having to charge for every session. I believe I saw figures that show that alkalines are typically lighter than NiCads and NiMH’s.

Considering the boy scout scenario then it must be an advantage to use the battery holder which came with his/her 2 channel surface dry cell radio without any extra expanse. Me too actually :slight_smile:

However, if a change were made to a lighter battery then would it not be a good idea to simply go from ‘AA’ to ‘AAA’. In that case we could still use a battery holder, recargeable NiCad or NiMH or dry alkalines as we do now.

Graham

20

I usually advocate the use of dry cells for about a year, so a sailor can get used to the boat & sailing first, then maybe change over to rechargeables after that. If a person has stuck with it for at least a year, then I would conclude that this person has what it takes to go the extra measure for rechargeables.

So for rookies, stay with AA alkalines. after about a year (one season) then go with your choice of power (AAA cells or rechargeables.) In fact, why not have that attitude for and new sailor?

thx