New Posts New Posts RSS Feed: V Twin
  FAQ FAQ  Forum Search   Register Register  Login Login

V Twin
 Post Reply Post Reply Page  <1 3637383940 142>
Author
  Share Topic Share Topic  Topic Search Topic Search  Topic Options Topic Options
Rupert View Drop Down
Really should get out more
Really should get out more


Joined: 11 Aug 04
Location: Whitefriars sc
Online Status: Offline
Posts: 8956 		Post Options Post Options   Quote Rupert Quote  Post ReplyReply Direct Link To This Post Topic: V Twin
    Posted: 22 May 12 at 9:34am
Originally posted by G.R.F.

Originally posted by L123456

 
When is it time to stop wasting your time with this and learn to sail one of the many many proven designs already on the market?

That time is never going to happen all the while they are old, flawed, and generally not fit for purpose imv.

I found this quote next to a post of Jimbo's on the other forum the other day, i thought it was eminently appropriate...

Ever tried, ever failed,no matter, try again, fail again, FAIL BETTER: Samuel Beckett
LOL


Quite agree. BUT, learning from the failure is pretty important, too. I should imaging your project has shown you that maybe, just maybe, there are reasons why some very clever people have designed or built things as they have?
Firefly 2324, Puffin 229, Minisail 3446 Mirror 70686
Back to Top
G.R.F. View Drop Down
Really should get out more
Really should get out more


Joined: 10 Aug 08
Location: United Kingdom
Online Status: Offline
Posts: 4028 		Post Options Post Options   Quote G.R.F. Quote  Post ReplyReply Direct Link To This Post Posted: 22 May 12 at 9:30am
Originally posted by L123456

 
When is it time to stop wasting your time with this and learn to sail one of the many many proven designs already on the market?

That time is never going to happen all the while they are old, flawed, and generally not fit for purpose imv.

I found this quote next to a post of Jimbo's on the other forum the other day, i thought it was eminently appropriate...

Ever tried, ever failed,no matter, try again, fail again, FAIL BETTER: Samuel Beckett
LOL


Edited by G.R.F. - 22 May 12 at 9:31am
https://www.ease-distribution.com/
Back to Top
L123456 View Drop Down
Really should get out more
Really should get out more


Joined: 30 Apr 12
Online Status: Offline
Posts: 500 		Post Options Post Options   Quote L123456 Quote  Post ReplyReply Direct Link To This Post Posted: 22 May 12 at 9:17am
Originally posted by G.R.F.

...probably too much going on what with a jib, main and kite to control, but there is room for someone else, so I've either got to make it lighter, or admit I've made it too big and rig it up with either an 800 or maybe a 49er rig and go see what it's really capable of.
 
Seems like a starting of acceptance that some of your design choices in the first place were poor  ... what comes next I believe is denial followed by anger ...
 
The design had a huge surface area so was ALWAYS going to be heavy ... the panel weight can only be shaved so much.
 
Plus the super stable design was ALWAYS going to be super stable upside down and as such a complete liability.
 
Throwing sail area at this project will do little to improve performance; many on here will concur that adding sail area adds little to performance. This will also make your inversion problems more likley.
 
When is it time to stop wasting your time with this and learn to sail one of the many many proven designs already on the market?
Back to Top
Presuming Ed View Drop Down
Really should get out more
Really should get out more


Joined: 26 Feb 05
Location: United Kingdom
Online Status: Offline
Posts: 641 		Post Options Post Options   Quote Presuming Ed Quote  Post ReplyReply Direct Link To This Post Posted: 22 May 12 at 8:55am
Originally posted by JimC

 
Mmm, I wonder how you'd specify a boat for bouncing off shingle... presumably it would have to be high density foam for dent resistance, and then something seriously kick ass for the outer skin on the bottom and at least past the chines... I suppose kevlar is an obvious choice for dent resistance, but I should think you'd want a few layers of glass on top of that just to give you something you could refinish readily without too much yellow fluff. The skin would have to be so ridiculously overbuilt for the beach bouncing that you wouldn't need carbon in there for strength. Its a lot of weight, that's for sure, because you'd need to run the heavy layup way past the chines in order to stop them chewing up. Probably getting close to doubling the weight of the shell I should think...

Or...
Back to Top
Daniel Holman View Drop Down
Really should get out more
Really should get out more


Joined: 17 Nov 08
Online Status: Offline
Posts: 997 		Post Options Post Options   Quote Daniel Holman Quote  Post ReplyReply Direct Link To This Post Posted: 22 May 12 at 8:55am
You'd go to monolithic glass - any sort of sandwich picks up more damage. About 4mm solid glass would be needed to match the stiffness of 8mm cored laminate.
That would be near 7kg per m2 as against 1.6ish for 200gsn carbon on 8mm 80kg foam so about a 20kg weigh delta on a cherub hull.
There would be another 8 kg for going with triple layered gelcoat for easy repair over spray paint finish.
Back to Top
G.R.F. View Drop Down
Really should get out more
Really should get out more


Joined: 10 Aug 08
Location: United Kingdom
Online Status: Offline
Posts: 4028 		Post Options Post Options   Quote G.R.F. Quote  Post ReplyReply Direct Link To This Post Posted: 22 May 12 at 8:45am
Well as I might have said previously I built an all kevlar boat once, a powered race boat for water ski racing where weight was important since we were racing in a restricted power class, it was too flexy and it literally fell in half as we nosed over the first wave (We were both in our work suits at the time we'd taken it out for a quick try out during our lunch break)
That was forty years ago, things have moved on apace since then, there have been all manner of composite constructions, ally honey comb, nomex honeycomb, styrofoam core, epoxy sandwich over styrofoam, abs over epoxy over styro foam, there are still 4 mtr craft that are thirty years old weigh under 18 kilos and quite capable of being run up the beach, it's just a sad fact that your/our market will never support the volume that would justify the production expense to produce what we're looking for.

Then again unless there is a culture, that demands it, why bother? All the time everyone is perfectly happy to think 40 kgs is light, then it's game on for these pathetic 'garage' construction systems to continue. I've not weighed this twin, but i nearly bust a gut hauling it up onto its side part of the reason it's holed and scarred is due to its sheer weight (and probably the additional water on board from what looks like a previous hole).

I'm not sure what to do with it now, what I'd like to do is take it to someone professional with the instruction cut it about and lighten it up, so if it did ever go over again I'd have a half decent chance of righting it and it might get on the plane with less than 14 sq mtr of sail area.

As I see it, there is way too much deck material, which was obviously an expedient way of getting it built, but is superfluous to making it go, if the two side tanks were able to flood, it wouldn't be such a problem and less likely to turtle. It needs a jib track and a few other changes to make it easier to actually get on with the job of sailing without niggling stupid things going wrong, the last time I actually sailed it, I got off at the gun and was making half decent progress against the fleet until I got the wrong side of a shift and then the kite just candled and failed to open then one of the sheets that had been mangled by the rescue boat on a previous recovery just fell off, so rightly it is back for a thorough overhaul and refit.

I really enjoy sailing it, it's such a challenge, probably too much going on what with a jib, main and kite to control, but there is room for someone else, so I've either got to make it lighter, or admit I've made it too big and rig it up with either an 800 or maybe a 49er rig and go see what it's really capable of.


Edited by G.R.F. - 22 May 12 at 8:47am
https://www.ease-distribution.com/
Back to Top
winging it View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 22 Mar 07
Online Status: Offline
Posts: 3958 		Post Options Post Options   Quote winging it Quote  Post ReplyReply Direct Link To This Post Posted: 22 May 12 at 8:32am
oh, now who do I know who has a single trap kevlar hull in her back garden.  reputedfly weighs 58kg..

http://www.ebay.co.uk/itm/120889664190?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
the same, but different...

Back to Top
JimC View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 17 May 04
Location: United Kingdom
Online Status: Offline
Posts: 6662 		Post Options Post Options   Quote JimC Quote  Post ReplyReply Direct Link To This Post Posted: 22 May 12 at 7:42am
Originally posted by I luv Wight

but I don't think it would survive being  run up the beach.

Mmm, I wonder how you'd specify a boat for bouncing off shingle... presumably it would have to be high density foam for dent resistance, and then something seriously kick ass for the outer skin on the bottom and at least past the chines... I suppose kevlar is an obvious choice for dent resistance, but I should think you'd want a few layers of glass on top of that just to give you something you could refinish readily without too much yellow fluff. The skin would have to be so ridiculously overbuilt for the beach bouncing that you wouldn't need carbon in there for strength. Its a lot of weight, that's for sure, because you'd need to run the heavy layup way past the chines in order to stop them chewing up. Probably getting close to doubling the weight of the shell I should think...

Better just to sail somewhere with decent launching I reckon!
Back to Top
I luv Wight View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 28 Jan 05
Location: United Kingdom
Online Status: Offline
Posts: 628 		Post Options Post Options   Quote I luv Wight Quote  Post ReplyReply Direct Link To This Post Posted: 21 May 12 at 10:37pm


Relatively easy for weight, ( 32kg for the Cherub above ), but I don't think it would survive being  run up the beach.

http://www.bloodaxeboats.co.uk
Andy P
foiling Int Moth GBR3467
Freedom 21 Codling
Back to Top
Jack Sparrow View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 08 Feb 05
Location: United Kingdom
Online Status: Offline
Posts: 2965 		Post Options Post Options   Quote Jack Sparrow Quote  Post ReplyReply Direct Link To This Post Posted: 21 May 12 at 7:29pm
last seen here: FORUM

Farr 3.7 Class Website
Farr 3.7 Building - Facebook Group
Back to Top
 Post Reply Post Reply Page  <1 3637383940 142>

Forum Jump Forum Permissions View Drop Down

Bulletin Board Software by Web Wiz Forums® version 9.665y
Copyright ©2001-2010 Web Wiz
Change your personal settings, or read our privacy policy