mast rake settings.. a few questions

[simon ballantine]

The Tuning Guide suggests a mast rake of 200mm to 400mm for a Design 8 with a Kappa mast.  Am I correct in assuming it should stay set at about of 200mm right through the wind range until we start to get overpowered, or should we be making gradual adjustments in intermediate wind strengths?

Is the suggested 200mm to 400mm rake an up-wind setting or applicable to all points of sailing?  Should I be letting the shrouds off to let the mast go all the way up to vertical when sailing down wind?

[RogerBrisley]

Simon,

I would have said yes,  unless it is survival conditions,  down wind  a design 8 needs a lot of" urge" to get up 'n go .  In my experience down wind is our slowest point of sailing.  I have contemplated using the Kappa which came with the boat (2nd hand) though the original mast was (and which remains in use) is a Proctor C, to improve the down wind performance though I have followed the advice of others and stuck with the C.

If its not a personal thing (?) what is your weight and that of your crew?  I' m anywhere between 12 and 13+ St which can restrict my choice of crew(daughter now at Uni was a good fit at 8 wringing wet).

Roger

3334 (D8)

ps watched you swimming early October though the gazette posted good results the week before

[simon ballantine]

I'm 11st7 and I normally sail with my wife who's pre-christmas weight is about 9st7.  (She never visits this website so I should be safe!).  When it gets seriously windy or cold she chickens out and leaves me with one of my two boys who are 10 and 12 and very lightweight...all the wrong way round really, but basically the boat wants to be set up for a combined weight of about 21stone.
I want to give the boat a good overhaul, neaten up all the control lines and get all my settings right over the winter.  At the moment there's far too much guesswork involved in the rig....too many variables!

Yes we have done a fair bit of swimming.  I even managed a windward capsize a broad reach on Sunday, which kept the fleet suitably amused.  Although a beginner to dinghy racing this season I now rate myself as a bit of an expert at righting the boat!

[John Meadowcroft]

Simon

Not necessarily the reply that you really want, but here goes....

There are 2 ways to measure rake.  Either get boat fore and aft horizontal (ie bow raised from normal trolley position and then pull the halyard down to gooseneck level and measure the horizontal distance between back of mast and halyard.  (could easily be 200-400mm) Here a larger number is more rake.

Alternatively just measure the distance between top of mast and centre of transom.  Here a smaller number is more rake.

Kevan Bloor goes for the first technique as I would assume that it is easier to transfer from boat to boat, but I would suggest is harder to measure.  Tom Stewart favours the latter as measurement is easy apart from the fact that different boats have different height transoms.

Now as you have a design 8 and P&B settings are based on 1991 (yes 1991 design 8 settings) I would follow Tom's method.  There is a tuning sheet on the P&B website that should help.  It is rumoured that the profile of transom on the P&B built Foolishes works to go with the design 8 rake settings, but this may only be a rumour!

Finally once you have your preferred measurement you should generally rake upwind as you get more overpowered.  My view is that once you are overpowered you should not worry about raking as much as you can.  Remember you need to get under the boom!  The key issue is determining firstly when to start and then secondly remembering that in 2 minutes time you may be underpowered and need to reverse the adjustment!

Offwind get the mast upright.  I would both pull on the jib halyard and ease the leeward shroud.  We use to pull the halyard on a couple of inches when we had a kappa on the final chapter.  Forget this advice if it is too windy, keep all the shrouds on and just worry about getting to the bottom mark!

Hope that this helps
john

[marcus3292]

u got a link to the P&B tuning sheet carnt find it

ta

[John Meadowcroft]

http://www.pinbax.com/docs/National%2012.pdf