Builder's Open - Any Thoughts?

[tmark]

The guantlet has been thrown ... a friend and I have challenged each other to design, build and race a boat against each other and all other comers. Target date is May of next year. Class rules are dead simple and apply to hull, appendages, rig and sails. Boat must be:

Owner designed.
Owner built.
Owner driven.

Monohull.
75cm LOA.

Why 75cm?
Anything bigger doesn't fit on my desk. Size requires a big dose of creativity and engineering. Less temptation to crib IOM and Marblehead pieces.

Why the owner restrictions?
They will reward what's in your head and not your mailbox.

I'd love to hear this group's input.
Any thoughts? Any comments? Anyone else want to have a go?

[Figgy]

Dump the mono restriction and I'll be there!

[Crag Cay]

It always seems that completely open rules make for the best races, but this is not always true. Sometimes simple 'box rules' at least keep everyone playing the same sort of game. It's a pisser when you spend all year honing your cricket skills to turn up and find everyone is wearing football kit.

You might want to take a look at the 'Strathclyde 70 class rules' (Google) which have a simple but interesting trade-off in them. (Draft and Depth measured from the mast hounds).

You could go through the rules and strike out those bits you don't like. For instance I think they are over prescriptive about the rig. However things like the restrictions on RC control channels make you prioritise the bits that make you go fast and not waste money on having multiple channels for things like a jib luff cunningham.

I am mentoring some youngsters going for next year's Strathclyde races, and they realise their campaign is going to need them to build a minimum of 3 hulls and 2 rigs.

[tmark]

If the project was about the race itself, I'd happily embrace an existing class, Strathclyde included. The idea, however, of not knowing who is going to show up with what is a big part of the appeal.

If someone can design, build and jam a canting keel mechanism into the envelope, wow, I'd love to see it and I'd happily lose against them. Likewise a ULDB with fixed wing. Or what if someone could figure out how to fly a kite off the front (...hmmm).

Creativity and imagination are a big part of any succesful design, whether it's within a box rule or not. In this case it will be really cool to give them free reign and see what shakes out.

As for cost, I'm guessing it will be limited by a builder's (my limited ones for instance) aspirations and ability. As nothing can be outsourced or bought, dollars are limited to the cost of materials, electronics notwithstanding ... not necessarily cheap granted, but not necessarily outrageous.

Cheers, Trevor

[marshmat]

Something like this? http://engsoc.queensu.ca/sailboat/Photos.htm A few of my colleagues at Queen's built and raced this earlier this summer; amazing little boat (it's sailed by its onboard computer, the crewman on shore just gives the rudder angle). It's about twice your target size, but a good source of inspiration....

[Crag Cay]

I think Marshmat has just illustrated my point. I was quite excited for a while, but my budgets just been blown out the water.

So long and enjoy!

[tmark]

Originally Posted by Crag Cay

I think Marshmat has just illustrated my point. I was quite excited for a while, but my budgets just been blown out the water.

So long and enjoy!

Point taken, Crag! Impressive project but holy smokes, what a way to up the ante ... thus, new rule ... no Canadian engineering students allowed ...

Seriously, if you were to limit electronics and at the same time allow for as much "boat" as opposed to "software" innovation as possible, what would your first instinct be?

Regards, Trevor

[marshmat]

Seriously, if you were to limit electronics and at the same time allow for as much "boat" as opposed to "software" innovation as possible, what would your first instinct be?

Huge rig, insanely long keel, low-drag monohull shape.
There were a couple of cats at that SailBot race; they were both insanely fast but had a tendency to pitchpole or capsize in gusts. In a little boat like this there's no time for the guy with the RC transmitter to react if there's a gust, the boat just goes over in half a second, so self-righting is really good.

[Figgy]

Originally Posted by marshmat

Huge rig, insanely long keel, low-drag monohull shape.

Exactly. I'd Probably show up with a few different sails/rigs too. Personally I wouldnt break the bank on the elctronics. Just a cheap radio with most the (electronic) budget spent on the small hi-power servos ..so when and where?

[tmark]

Originally Posted by Figgy

..so when and where?

Right on, Figgy ... !

Provided I can talk the sailing committee into it (and even if I can't) how about the dinghy docks at RCYC in Toronto. I'll sponsor. Late May, early June 2007.

Keep in mind that depending on lake levels, a draught deeper than 1.5 metres could get you into weed troubles.

Regards, Trevor

[sharpii2]

Originally Posted by tmark

The guantlet has been thrown ... a friend and I have challenged each other to design, build and race a boat against each other and all other comers. Target date is May of next year. Class rules are dead simple and apply to hull, appendages, rig and sails. Boat must be:

Owner designed.
Owner built.
Owner driven.

Monohull.
75cm LOA.

Why 75cm?
Anything bigger doesn't fit on my desk. Size requires a big dose of creativity and engineering. Less temptation to crib IOM and Marblehead pieces.

Why the owner restrictions?
They will reward what's in your head and not your mailbox.

I'd love to hear this group's input.
Any thoughts? Any comments? Anyone else want to have a go?

Dear tmark:

Three suggestions:

1.) Remove the mono restriction. It seems to have no pratical purpose other than ratcheting up the cost up to that of a manned racing dinghy. The guy with the carbon fibre hull, the canting ballast, and the Kevlar sails is gonna get the silver in any mono only race. Mono's make excellent crusing boats, but, when not restricted by some really complex rule, very e$pen$ive race boats.

2.) State race course conditions. Is this a triangular course? A cross wind course? Or a dead down wind course? What are the draft limits of this course? Are there any wind speed limits, minimum or maximum?

3.) Better state the boat limitations. Are these dumb pond sailors? RC boats?
If they are RC boats that should be stated in the rules. And, also, if they are, are there any limits on how many channels they can have? Can they have computer chips on board?

The fundamental question I think you should be asking yourself is this: Is this a contest of creativity or of who has the most money and or access to expetise. If it's a contest of creativity, you are going to need a lot more restriction than you now have.

The trouble with anarchy is that, although it looks very good on paper, it almost always ends up becoming a shooting contest.

Bob

The problem with an effective canting keel on a model is that it gives you great power to carry sail. That, of course ,is also the advantage until you round the windward mark. Then you may have trouble because most models have poor pitch resistance and canting keel models are the worst of the lot. Downwind the canting keel does very little for you yet now you have this big sail area making the boat even more prone to nose dive. I've spent many hours building and testing canting keel prototypes and what I've finally decided is that there needs to be on-deck sliding ballast along with the canting keel so some ballast can slide aft. More complexity but great speed. 5ch radio ideal....
Take a look at www.microsail.com just for the hell of it. Mostly boats that are too complicated(costly ) for your purpose but you may find them interesting. In multihulls, I found that by using hydrofoils the boat would develop it's own righing moment and be rock steady in 0-22mph of wind but without retractable foils dog slow in light air. By light air I mean under 5 knots since it would fly in 5-6. See the F3.
There is a simple way to use a spinnaker on a small boat like you propose but it needs a $230 winch for set/douse and the spin itself will cost over $80 plus a minimum 4 channel radio. The advantage, if installed properly, is that the spin will lift the bow ,absolutely preventing nosedives. You can figure on gaining only about 40% more SA.
I'd suggest going for a narrow mono with thin foils(6-7% t/c ratio).Keep it simple the first time . Look around on the AMYA site for references to the US one Meter class and, of course, check out Lester Gilbert's site.

[frosh]

Really good idea Doug. Stick to small RC yachts; it suits you better!

Frosh, many people have loads of fun racing and sailing rc models and learn a lot about rules, design, building, sails ,balance etc. And a few use rc test models as part of their design and development process in exploring new ideas. You should consider it as well -might help with your understanding of some modern technology.

[frosh]

Doug, my last post had no sarcasm at all (honest). I have built a model powered hydroplane many years ago. Did a "Howard Hughes" with it, and after two test runs, it went extremely quick in a straight line but flipped on every corner, it has been sitting in the garage gathering dust for what seems like an eternity. I couln't get excited about model boats to ever modify it, or build a second version.
I don't need to test my experimental sailing theories with models as I believe that the reality of scaling up that much loses the reality of valid comparisons.
And my comment to you is the same; do what you will with models, and have fun, but then don't espouse the results of this experimentation to the real thing. There may be some relevance to a real boat only 11 foot long, but the bigger you go the less likely that what works for a RC model will actually be a success, or even be sailable at all.