Tuning Tips for the RC Laser
The design and engineering of the RC Laser leaves the skipper with a relatively small range of performance adjustments. Because there are so few, they are fairly critical. What follows are basic guidelines that the skipper must fine tune to the wind and sea conditions.
The two major adjustments involve the sail. They are foot curve of the sail and the leach twist. In a light wind, more foot curve and a less leach twist are best. In a heavy wind, aim for little foot curve and more twist.
How are these sail adjustments made?
At the aft end of the boom are two sliders. The forward one is for tensioning, the aft slider adjusts the angle of outhaul tension on the sail. If you slide the aft slider forward, the tension angle is more down than out. So tensioning with the forward slider tightens the leech, and allows the foot to curve away from the boom (foot curve). This produces draft that powers the boat in light wind.
As the aft slider is moved further aft, the angle of tension changes to distribute the tension more equally on the leech and the foot of the sail. In this position, a puff of wind bends the mast causing the leach to twist spilling air which helps the boat stay upright. The lower section of the sail stays properly trimmed to help power the boat through the puff.
What is the proper amount of foot curve for a given wind condition?
A good indicator is boat balance (helm pressure). If the boat is able to sail itself to windward with little or no steering correction (neutral helm), then the foot curve is about right. Too much weather helm (the boat rotating into the wind) indicates that you need to flatten the foot curve. A leeward helm (the boat falling off the wind) shows a need for an increased foot curve.
When to switch sails
When sailing downwind and the bow begins to dive, switch to a smaller sail. Sometimes, changing down in sail size right before this point can make the boat a bit easier to handle. Experience will help you determine the best time to change.
Sailing in choppy water
Increase twist so you don’t stall the sail as the boat pitches through the waves. A little windward helm is not a bad thing, since it shows you where the wind is coming from.
Proper boom position
Most top sailors agree that sailing upwind with the boom just inside the aft corner of the stern is the proper location. Pinching the sail further inboard produces a boat that goes upwind at a closer angle, but it travels much slower through the water. This position is used for temporary handling to get around a mark or obstacle, but does not provide optimum performance. With the boom just inside the aft corner of the boat, you will find the Laser develops the best speed, and angle to windward.
To make positioning of the boom easier to set when you are not close enough to the boat to see it clearly, adjust the length of the mainsheet so that the boom is just slightly inside the corner of the transom when the sail control stick is all the way down, AND the fine tune slider is in the middle of its range.
Now when you round up to go on the wind, push the stick down all the way, and check to make sure the fine tune slider is in the middle. Then you know the sail is going to stop in the best position. If you need to get the boat going in a chop, slide the fine tune up a little to slack the boom out and fall off slightly. If you need to pinch up momentarily to avoid an obstacle or make a mark, slide the fine tune down.
In light winds it is important that you never tension the outhaul to the point where it bends the mast (it will always affect it a little, but nothing of note). At the opposite end of the scale, when the wind is blowing hard, then you will first have your aft slider all the way aft, and you will tension the sail so that there is little or no foot curve. Now the outhaul tension will bend the mast so it pretty well fills out the luff pocket (leading edge of the sail).
Concentrate on steering your boat in a straight line – remember the shortest distance between two points is a straight line. Over-steering model sailboats is a common fault, one you can overcome with practice.
Also remember that every time you turn sharply, the rudder acts as a brake, slowing your boat speed.
These tips should give you a good start on fine-tuning your RC Laser’s performance.
These guidelines were written by Jon Elmaleh and they were edited by Abigail Kelly and Steve Lang.