North Sails RESOURCES
Farr 280 Tuning Guide
- Last Updated: Agosto 23, 2017
- Tuning Guide (PDF)
The Farr 280 is a relatively light boat which makes it very receptive to positive trimming. It is imperative to have the
sail trim spot on but also the fore and aft weight trim correct and whichever team does this the best will be rewarded with the best boat speed. Up to 7 kts the Farr 280 is always looking for more power so keep the sails powered up, focus on building speed efficiently out of transitions (tacks, jibes, ducks and mark roundings) and don’t over trim or you can easily kill the speed.
Take your rig tune seriously. Keep whoever adjusts the rig the same from the beginning to the end and you will be far more accurate all season long. It is one item on our list we can get right before we leave the dock.
• Loos Gauge PT-2 (headstay, V1 and D1 shrouds)
• Loos Gauge PT-1 (D2 shrouds)
• 30 m (100’) tape measure (forestay pin-to-pin)
• 5 m (16’) steel tape measure (mast heel)
• Rig spanners (adjustments)
• Setting Up the Mast
Set the mast plate in the correct location.
Before the mast is stepped, place the aft
face of the mast step 455 mm (17.91”)
forward of the forward keel bolt center
line. Measure from the white line to the
forward keel bolt (Fig. 1).
Step the mast and attach the headstaystrop to the lower headstay fitting
Attach the cap shrouds only just past hand tight.
Measure down from the upper
measurement point (Fig. 3) and make a
mark on the headstay 11.92 m (39.11’) from
the top point.
Pump up the mast on the hydraulic jackso that it just lifts off the collar. Then pump the headstay down (shorter) so that your headstay mark of 11.92m (39.11’) becomes just even with the plate in the headstay well.
Measure back from the headstay to the same location on both sides of the boat even with the partners. Make a mark on the partners halfway between these 2 points. This locates the centerline of the mast on the boat’s centerline.Using the supplied chocks center the mast on the centerline of the shrouds. This may entail sanding the supplied plates to fit the partner hole. Once centered, screw the plates to the chocks through the sidewall of the partners so that none of these fall out while sailing. Eventually the mast should be held in place with “Spartite.”
Using the centerline halyard measure down to the mark from Step 6 on both sides of the boat aft of the headstay.
Adjust the cap shrouds so that this number is the same on both sides. Now your “hounds” are centered.
NOTE: It is extremely important that there is no “load” on the shrouds when you adjust the nuts (Fig. 6). If there is toomuch load you may either strip or cross thread the rod. To adjust the nuts you must “drop” the mast, adjust, then pump back up.
Use an ARC measurement to get the correct 1.5° rake at the correctmast butt height. Take the centerline halyard, measure 1.00 m (39.37”) down from the boom band, swing the halyard to the headstay and mark headstay. Pump up the mast until this headstay mark is 684 mm (26.93”) above deck. Place a straight edge over the headstay well to get this measurement.
Note: how high the bottom of the mast is relative to the mast plate. See Step 9.
Obtaining the correct cap (vertical) shroud tension. With the mast pumped up so that the headstay ARC measures 684mm (26.93”), note the mast butt height. In the case here it is 78 mm (3.07”). With the headstay at 1.5° rake and the mastraised 78 mm (3.07”) (Fig. 8). You want the jack pressure to read 1925 psi or 133 bar on the cockpit dial with just the headstay and cap shrouds attached. You will need to raise and lower the rig a few times to make the necessary adjustments to the cap shrouds.
Repeat Step 9 when attaching the D1s with the caps (verticals) and headstay. Use the PT-2 Loos Gauge to get 28 units on the gauge for the D1s.
Repeat the Step 10 while attaching the D2s, D1s, caps and headstay. Use the PT-1 Loos Gauge to get 26 units for the D2s.
With all standing rigging attached, check the finished tune with the Loos Gauges.You should have the Loos Gauge units listed below for the BASE settings. The mast butt height will be relative to your boat. Hull #1 was 78 mm (3.07”).
We set BASE settings for this boat at maximum load. From this point the tuning relates to lowering the mast butt
height combined with lengthening the headstay to soften the rig loads as the wind speeds diminish.
BASE Settings for 18+ kts TWS
Rake 1.5 °
Mast Butt 78 mm
Headstay 39 PT-2 Loos Gauge
Caps 43 PT-2 Loos Gauge
D1s 28 PT-2 Loos Gauge
No diagonal or vertical shroud adjustments should be required with this rig. Primary adjustment is with the headstay and mast butt ram. Headstay and mast jack pressures can be referenced using the hydraulic pressure gauges on the control panel.
1° of rake change = 53 mm (2.09”) change to the headstay length. With the mast
set at 1.5°, use a batten set down into the bottom of the headstay well to mark the batten at the centerline of the headstay pin shown in the photo below. Tighten and ease the headstay in 26 mm (1.02”) increments and mark the batten from 1.25° to 3°of rake. Use this batten for a quick reference when tuning.
Use the centerline of the headstay pin to measure rake while sailing the boat. The red line shows the centerline of the pin. D2s 26 PT-2 Loos Gauge For lighter winds we recommend a combination of dropping the mast down and lengthening the headstay. This promotes sailing with a softer rig laterally while sailing with more rake.
Three marks that help when sailing
1. On the under side of the spreaders make a mark to reference the headsail leech when sailing:
Lower Spreader: 635 mm (25.00”) from mast centerline
Upper Spreader: 476 mm (18.74”) from mast centerline
2. Mark the headstay to be visible from the cockpit/rail. The red marks below note 1.5° (upper) and 3° (lower) of rake when parallel to the deck height.
3. Mark the maximum down position on the aft face of the mast (shown below with white electrical tape. But this should be marked in a more permanent manner.