Mini Freesail Cat board thing
Printed From: Yachts and Yachting Online
Category: Multihulls
Forum Name: Dinghy multihulls
Forum Discription: For those who prefer two (or more) hulls to one!
URL: http://www.yachtsandyachting.com/forum/forum_posts.asp?TID=4693
Printed Date: 09 Aug 25 at 2:21am
Software Version: Web Wiz Forums 9.665y - http://www.webwizforums.com
Topic: Mini Freesail Cat board thing
Posted By: G.R.F.
Subject: Mini Freesail Cat board thing
Date Posted: 27 Sep 08 at 7:54pm
|
Not sure where to put this, it's a cat in as much as it has two defined
hulls, it's to be powered by a windsurf rig in a hope to make me feel a bit safer putting the hammer down in 25 knots plus. Launched it today, we had no wind, so it was just a float test, see how it rides in the water and i shoved it about to check it would lift onto the plane. It's made of ply, glued, screwed and nailed together from bits costing less than £100. It's been an idea that's been kicking around my head for some years, loads of sketched and doodles but everytime i asked someone to build it they thought I'd lost the plot, which clearly i have, but if I get proof of concept out of it, and it gets through the speed course at anything approaching a respectable speed (anything over 30 knots) and I'll be happy. It's way too heavy, I daren't even weigh it. It's got a three stage rocker, final planing wetted surface a minimal 2.4 sq mtrs, inside two kite bladders should ensure even if it leaks, not too much water ingress will occur, now it's finished you'll notice the winds gone. Ayway i just thought y'all might be interested. 
|
Replies:
Posted By: Ross
Date Posted: 27 Sep 08 at 7:58pm
|
From sailing Cherubs, I know looks can be deceiving. But I don't think this is going to work very well. Hats of for building it though! ------------- Ross If you can't carry it, don't sail it! |
Posted By: G.R.F.
Date Posted: 27 Sep 08 at 8:15pm
|
Here's a bet, and I've genuinely no idea, it hasn't had a rig on it.
But I bet i can get that to go a lot faster than Flat Stanley. Shall we say a tenner? |
Posted By: Splosh
Date Posted: 27 Sep 08 at 8:21pm
|
Hi GRF. Well done, she does look like a fast bit of kit Also whats the idea of the angled fin? is it just a anti-weed one or does it give it a boost of performance? And finally could we see a piccy from the top? Looking good though! Mark. ------------- RS300 - 346 :D |
...but how would u steer it? Surely it would be a complete nightmare to carve with no obvious rails etc.
, is there staps and all... or would that be telling 
Posted By: Ross
Date Posted: 27 Sep 08 at 8:33pm
|
G.R.F, your on! As long as you tow me there an back! Angled fin, bow up trim? ------------- Ross If you can't carry it, don't sail it! |
Posted By: G.R.F.
Date Posted: 27 Sep 08 at 8:41pm
|
The weed fin was an idea I'd had a while back to reduce drag, I was going
originally without a fin, then I had this idea for a fin'wheel' then given so much experimentation best to prove one thing at a time. Weed fins are foiled at that angle so you're not dragging the foil by sweeping it back. Straps and pads not in place yet, wanted to sail it first, get a feel for where I'll need to put them.. No need to steer it really, speed sailors just blast down a straight course, get off the other end, turn their board around and sail back, no need to even gybe. 
|
Posted By: Ross
Date Posted: 27 Sep 08 at 8:48pm
|
How much sail is it going to be carrying? ------------- Ross If you can't carry it, don't sail it! |
Posted By: ratface
Date Posted: 27 Sep 08 at 9:06pm
|
looks like it would be quite interesting to watch good luck with it Graeme, remember to get some video of it moving. Ross: seeing as it will take a windsurf rig im sure it will be able to carry a silly amount of sail area, right down to the damn right small in a blow ------------- http://www.blym.org.uk/ - BLYM http://www.blym.org.uk/hydrs/index.htm - Hertfordshire Sailing team Uk-Cherub 2644 Laser 4000 -4089 |
Posted By: G.R.F.
Date Posted: 27 Sep 08 at 9:35pm
|
I have a very light 9.5 mtr rig, which is bigger than a moth.
I will also use my variable luff curve invention from a couple of years back, a 7 mtr I managed to get through the course in a 48 knot wind, but the board I was using back then was slow. There's a bit about it http://www.surf-sales.com/vbulletin/vbulletin/upload/showthread.php?t=96 - here it's good for 31.5 knots on an old dog of a board. Anyway we can talk all we like, the proofs in the pudding, but it'll be fun using stuff I've built myself, I'm usually totally useless at making things, i can design them, but make them happen.. no chance. |
Posted By: Chew my RS
Date Posted: 27 Sep 08 at 9:52pm
|
GRF - what's the thinking behind why it should be quicker than a single hulled board? It reminds me a bit of a pair of waterskis held rigidly together, with a fin poking down... ------------- http://www.sailns14.org - http://www.sailns14.org - The ultimate family raceboat now available in the UK |
Posted By: G.R.F.
Date Posted: 27 Sep 08 at 10:47pm
|
A pair of waterskis held rigidly together is exactly what it is.
Way back, I used to waterski race. At one time from a limited power source, and we always found that a pair of skis were always faster than one mono, and the mono always had more drag, widening the footprint spreads the load I guess. Unforunately at 50 mph+ a pair of skis were uncontrollable in chop, no-one could stay up on a pair at very high speed, the stance on a mono is more stable. So that and the fact cat powerboats were always faster than mono, we all know cats are faster than mono dinghies and no-ones ever built a fast cat windsurf board and there you go.. |
Posted By: mike ellis
Date Posted: 28 Sep 08 at 6:14pm
|
so is speed week next week? or is it some other date? next week looks pretty good for wind, especially tuesday onwards. ------------- 600 732, will call it Sticks and Stones when i get round to it. Also International 14, 1318 |
Posted By: G.R.F.
Date Posted: 08 Oct 08 at 11:23pm
|
In case anyone wondered, it sank, at least the forward compartments of the
nose section filled with water while i was trying to get it on the plane in what was the best part of thirty knots.. I kind of skimped on the kite bladders in the tow forward sections, had sort of figured they'd be planing out of the water for the most part anyhow.. Whatever, back to the drawing board, just further proof Cat's are useless.. |
Posted By: Ross
Date Posted: 08 Oct 08 at 11:57pm
|
You owe me a 10er.
------------- Ross If you can't carry it, don't sail it! |
Posted By: ellistine
Date Posted: 09 Oct 08 at 9:02am
|
I saw it on the WPNSA slip last weekend and wondered if it was anything to do with you Grumpf. Still, well done for getting it out there. It was a little bit breezy. ------------- |