New Posts New Posts RSS Feed: Adjustable raking systems
  FAQ FAQ  Forum Search   Register Register  Login Login

Adjustable raking systems

 Post Reply Post Reply Page  123>
Author
iGRF View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 07 Mar 11
Location: Hythe
Online Status: Offline
Posts: 6028
Post Options Post Options   Quote iGRF Quote  Post ReplyReply Direct Link To This Post Topic: Adjustable raking systems
    Posted: 17 Nov 20 at 9:56am
One for the technically minded this.

I'd like a single string raking system that adjusts the lowers simultaneously.

I'm sure I've seen it in Merlin World and wonder if anyone has some sketches as to how the pulleys line up.


My second question is, insteaad of raking the mast back top down has anyone ever come across anyone sliding the bottom of the mast back and forth windsrf longboard racing style, pivoting around the top spreader shrouds? (Obviously the lowers would have to adjust in concert also)

Edited by iGRF - 17 Nov 20 at 9:57am
Back to Top
davidyacht View Drop Down
Really should get out more
Really should get out more


Joined: 29 Mar 05
Online Status: Offline
Posts: 1085
Post Options Post Options   Quote davidyacht Quote  Post ReplyReply Direct Link To This Post Posted: 17 Nov 20 at 10:50am
You probably should delve in the various Merlin Rocket forums, since I believe that there are two types of Merlin one string systems.  Look on the main website and also the Merlin Revival Facebook pages.

Unless you are a consummate boat bimbler you might look to get one of the Merlin gurus sort it for you.

Dick Batt had a ramp system for the mast foot, I think on Danger Bat.  This might be less complex.

I suspect that you could achieve 90% of this by having a decent forestay tensioning system and a decent and powerful shroud tensioning system, and ensuring that these are carefully calibrated.  In National 12s we simply dumped the shroud tension at the windward mark to allow the main to square off, and pulled it back on at the leeward mark.  We had three windward rake settings marked off on he control line ... light, medium and windy.

Happily living in the past
Back to Top
Gordon 1430 View Drop Down
Far too distracted from work
Far too distracted from work


Joined: 27 Jun 17
Location: Lee on Solent
Online Status: Offline
Posts: 254
Post Options Post Options   Quote Gordon 1430 Quote  Post ReplyReply Direct Link To This Post Posted: 17 Nov 20 at 10:53am
HI Grf
I had a 505 which had tracks on the shrouds so you could adjust them fore and aft in conjunction with raking the rig.
You have a short length of tack on each gunnel with a car on top which the shrouds attach to and the cars have a control line to pull forward or aft.  Mr Henshall might have some images of Grace which may have been one of the first with this system.
Good Luck
Gordon

Gordon
Phantom 1430
Back to Top
davidyacht View Drop Down
Really should get out more
Really should get out more


Joined: 29 Mar 05
Online Status: Offline
Posts: 1085
Post Options Post Options   Quote davidyacht Quote  Post ReplyReply Direct Link To This Post Posted: 17 Nov 20 at 10:56am
Grace ... special boat
Happily living in the past
Back to Top
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: 8761
Post Options Post Options   Quote Rupert Quote  Post ReplyReply Direct Link To This Post Posted: 17 Nov 20 at 11:36am
A moving mast foot pivoting round the hounds will rake the mast but affect CofE rather differently. Good or bad I don't know.
Firefly 2324, Lightning 130, Puffin 229, Minisail 3446
Back to Top
H2 View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 26 Jul 17
Online Status: Offline
Posts: 610
Post Options Post Options   Quote H2 Quote  Post ReplyReply Direct Link To This Post Posted: 17 Nov 20 at 11:51am
Originally posted by Gordon 1430

HI Grf
I had a 505 which had tracks on the shrouds so you could adjust them fore and aft in conjunction with raking the rig.
You have a short length of tack on each gunnel with a car on top which the shrouds attach to and the cars have a control line to pull forward or aft.  Mr Henshall might have some images of Grace which may have been one of the first with this system.
Good Luck
Gordon


I think Tasar use a track at the shrouds too?
H2 #115
Back to Top
Dougaldog View Drop Down
Far too distracted from work
Far too distracted from work


Joined: 05 Nov 10
Location: hamble
Online Status: Offline
Posts: 326
Post Options Post Options   Quote Dougaldog Quote  Post ReplyReply Direct Link To This Post Posted: 17 Nov 20 at 12:05pm
Mr Henshall has indeed pictures of the tracks and of the hydraulic  shroud tensioners that were fitted at the time.  In the end, Chris Haworth did this best...Merlins and 5o5s! However, with the ready availability of modern, low friction/high load blocks, the complication that the system introduced could be best handled with a merlin style one string. What is really needed here is the Jon Turner 'big wheel of love' but my gut feel is that the cost of doing this will drive the man of Kent into another rage - even a fairly bog-standard one-string system on a Merlin can gobble up a cool £1000+ in hardware and cordage. Sadly, the OP won't accept that this has been done before, albeit somewhat differently - who can forget that Jon Turner (one of our great innovators of things that work) had a system on Dark Star that allowed the rig to be heavily canted to windward. 
The $64,000 question though.... all that knowledge and expertise in one boat (Turner and Richard Parslow) and a fully functional system - get they didn't proceed to develop it further - which must beg the question...why not!
Dougal
Dougal H
Back to Top
A2Z View Drop Down
Really should get out more
Really should get out more


Joined: 10 Oct 16
Online Status: Offline
Posts: 501
Post Options Post Options   Quote A2Z Quote  Post ReplyReply Direct Link To This Post Posted: 17 Nov 20 at 12:21pm
Does your Fireblade need lowers, spreaders or even shrouds? Stick an OK or D Zero rig on it and have a sliding mast foot. Much easier, tidier and cheaper than a Merlin one string system. 
Back to Top
iGRF View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 07 Mar 11
Location: Hythe
Online Status: Offline
Posts: 6028
Post Options Post Options   Quote iGRF Quote  Post ReplyReply Direct Link To This Post Posted: 17 Nov 20 at 12:47pm
Originally posted by Dougaldog

Mr Henshall has indeed pictures of the tracks and of the hydraulic  shroud tensioners that were fitted at the time.  In the end, Chris Haworth did this best...Merlins and 5o5s! However, with the ready availability of modern,


Well, let's see them then?

Why didn't they continue? Easy obvious answer to that.

I came across this Supernova, it was allegedly the 2014 Nationals winner on display at some show or other, but it had some sort of system, wish I'd paid more attention and taken more pics.

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

Joined: 07 Mar 11
Location: Hythe
Online Status: Offline
Posts: 6028
Post Options Post Options   Quote iGRF Quote  Post ReplyReply Direct Link To This Post Posted: 17 Nov 20 at 12:49pm
Originally posted by A2Z

Does your Fireblade need lowers, spreaders or even shrouds? Stick an OK or D Zero rig on it and have a sliding mast foot. Much easier, tidier and cheaper than a Merlin one string system. 


Well I assumed because I want to trapeze from it, it would need additional support, has anyone ever trap'd off an unstayed rig? Is it do-able? I agree getting rid of all that dross would be great but....
Back to Top
 Post Reply Post Reply Page  123>

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