Merlin Rocket Tuning Guide

Rig Tension

Tight, measured on Jib luff wire 250/300 lbs.

Mast Rake

Variable

Spreaders

Length measured from the shroud to the side of the mast.

Check sweep back of spreaders by placing a straight batten from the port spreader tip to the starboard one. Measure from the centre of the batten to the rear of the mast.

Mast: M1
Length: 365mm
Sweep Back: 150mm

To make the mainsail fuller swing the spreaders forward. To flatten the mainsail swing the spreaders aft.

Prebend

Check with jib only hoisted and the rig tension on.

Measure to a straight line between masthead and the black band at the gooseneck.
With mast in light wind rake (ie.fairly upright) Prebend =40mm.

Lowers

Use lowers to control mast bend and power in the rig for various conditions

Jib Sheeting

With the jib pulled in tight, the continuation of the jib sheet from the fairlead to the clew should intersect the front of the jib 1900mm up the luff wire. When over powered in heavy winds move the fairlead aft to flatten the jib and open the slot between the jib and the mainsail.