Boat Tuning

Tuning starts before I leave for a regatta. I install all the rigs and check the base settings are within tolerance and the transmitter works. It is amazing how cord shrinks after a weekend of salt water. Also check the gooseneck bearings are OK.

Transmitter set up.

I want to sail my boats like a dinghy.  In my youth I always played the mainsheet according to the variability of the wind and even did the same on yachts. Having seen a video of me sailing my IOM, everything looks very stiff and rigid in comparison to what I used to do. I changed my transmitter setting and now constantly play with the fine tuning. The setup is organised so I have to play the sheets. The starting position where the sheet stick is all the way down is as per the start of the video. Then as I move the sheet stick to the left you see the sail come in all the way to the centre high mode.

Ease in gusts for max acceleration or VMG, sheet in for high mode off a start line or away from a leeward mark. I use this transmitter setting for all rigs. You can see two Day-Glo strips with black lines on the deck which I use for checking my high mode boom positions so I have the correct starting point.

Lastly before launching I check the rudder is centred.

Rig set up

As a rule, before I put the boat on the water I check my initial settings, but the real work is done when the boat is sailing. If it looks right and feels right, find another boat and see how fast you are. Look for lee or weather helm and adjust accordingly. In chop, it is harder to judge feel as the boat is pushed around a lot. Here are some ideas for each rig. On the DF's a lot of my setup is down by eye and how the boat feels on the water.

A+

Rough settings are written on my sails.

Main foot 20-30mm deep

Jib foot 10-20 mm deep

Jib leech twist, approx 30mm

Main twist is set to balance the boat.

Unlike most I do not set my mast ram at deck level on the aft notch as I find it gives me too much weather helm.  I follow the rigging guide a little. The mast ram guides the mast rake. Mine is usually set on the middle notch. To start I loosen the deck support to set up a straight mast then tighten the deck support. 

When the boat is sailing it should be balanced, no lee or weather helm which can only really be detected on flat water as the boat gets pushed around in any chop.

Tell tales are wool sprayed with "Fly Float" so they stay non stick in the rain. I use 2 or 3 tales on the jib and main depending on the size of the boat.

Rough settings for the foot and leech measurements are written on the sails as in the photos above so I do not have to remember them.   Flatter for flat water, deeper for chop.

Twist – same as depth.  Flat water light wind - less twist, chop more wind - more twist.  If you have trouble tacking, decrease twist on the jib and add more to main.  Remember only tiny adjustments

Checking twist.  Set up in a room flapping the sails from side to side or point boat away from you if outside downwind. Never set the rig up by sheeting in and pointing into wind. The loads will be way to high.

You are looking for a jib twist that is in line with main body of the main and the main leech twist should match the jib leech twist.

You are not looking for precise measurements. There are several wasy to set the boat up and they can all work so measuring to the mm is a waste of time.

A rig

The A rig covers a very narrow wind band of 3-5mph but comes into its own in gusty conditions, when you need the power in the lulls but not so much power you nose dive in the gusts.

Mast support is set right back at deck level.

Rake is determined by amount of mast bend needed.  Set the backstay for slight bend and then tension jib.  Balance forestay and backstay tension to get max tension without too much mast bend.  Too much bend and the mainsail will invert, too little, the jib luff wobbles

The most important thing about the A is mainsail twist.  The jib is too small for a balanced rig if the kicker is too tight. If you think you have enough twist in the main, add more.  If you struggle to tack add more main twist.

B

Mast support right back at deck level.

Set up with max tension in jib luff and backstay. Jib twist should be 10-25mm from topping lift depending on conditions. The main should again match the jib twist.