How much rake is no rake?

[jonathan_twite]

Hi all
I am needing to shorten the shouds and jib halyard on my Paper Dart as I currently have almost no tension in the rig (goes like the clappers in a F0 - F1, anything stronger, she just heals in gusts without going forwards...).  The boat has on/off shoud levers but no other fine adjustment to use when afloat.  In order to measure the lengths we need the shrouds and halyard to be shortened by (probably more than 1.5 inches each) I would like some advice on "standard" settings.
In zero - very light winds I sail with mast ram on and shroud tension off both sides, both upwind and downwind.  Is this bad practise?
In light winds I sail with maximum jib halyard tension and mast ram to try and get as little rake as possible (that is, mast as upright as possible).  How upright is the most upright that should be used?  Hanging a weight off the main halyard at the moment means it hangs 6-8 inches back from the goose-neck.  Should I be aiming to get the halyard to touch the mast as my light-wind, zero-rake setting or hanging a few inches back?  Is this measured with or without mast-ram on or sail up?
On a related question, does the spirit-level-on-centreboard-casing method for leveling the boat work, or do we need to measure this while afloat?

Thanks for any advice you can give

[johnk]

In my experience the "spirit level on centreboard case" method works well as it is very consistent. The 6 to 9 inches gap aft of the mast at the gooseneck when hanging a weight from the main halyard (in low wind!) seems a good base point. It should be done with the mast straight, mainsail down and the jib hoisted with normal tension (but loosely rolled around the forestay). You will have to find what variation from this suits your boat under what conditions. Note that altering the mast rake and not the jib fairlead fore and aft position noticeably alters jib sail twist when close hauled....

[jonathan_twite]

I assume that that is as measured with the mast ram off?

[Chadders]

Hi the only time you should have your levers off is my book is the lee one when sailing off wind, the mast rake John suggests is ok although I have a bit more even in the light stuff and the rig tension is set up tight as per the tuning book or just a bit less. The spirit level on the plate case works fine for level as does a weight on the main halliard but you need a near wind less day or it just blows around.  Use a rig tension gauge to set the rig tension and try for 25-30mm of mast bend in the middle of the luff, use the main halliard pulled tight to the gooseneck to gauge this.  All 12 rigs, masts, sails and layouts are slightly different so you will need to experiment.  Follow the tuning guide as a start then alter one thing at once until it is going well.  The best way to check rake is with a tape measure from the top of the mast to the middle of the transom (tie it to the main halliard and hoist it) but there is no standard size as the transoms vary in height etc and the guide is I think OK for a Foolish or a Design 8 so start with John's method then use tape to transom as a check/ref point.  Sailing upwind with levers off is asking for a bent mast both should be on upwind.
 My Paperdart is faster than both my Starfish and My Design 8 in the light stuff despite very old sails but like you I lose out a bit in a breeze but then I have a very soft rig and sail with circa 23 stone.  We managed a first and two seconds in our light wind open meeting in a fleet including 2 Feeling Foolish, a Numinous, a D8, a Baggy and several other AC boats a couple of weeks ago.  Best advice Read the Tuning guide and How to set up your 12 along with other bits on this website it is the best resource you can get and it is free.