Antrim 27 Association Rig Tuning

Rig Tuning for Ballenger mast

These guidelines were developed by Jim Antrim

Mast pre-bend should be smooth curve matching the mainsail luff curve within these guidelines:

* Pre-bend at upper spreader ~4.75"
* Pre-bend at lower spreader ~5.50"

Mainsails should be cut for this mast pre-bend. A straight mast is in danger of inverting under spinnaker loads!!!

In round numbers:

* V1 tension = D2 tension + V2 tension.

After starting with these suggested initial static tuning tensions (see below), the uppers (V1) often have to be adjusted to get the mast pre-bend to match with the mainsail. If this requires changing the lowers (D1) more than 5 turns on the turnbuckle, talk to the sailmaker about an adjustment to the luff round.

If there are overbend wrinkles up high with the initial tuning, have the sail recut. Do not attempt to fix this problem by slacking off V2.

Tighter lowers (D1) will decrease the tension setting of the uppers (V1) with headstay at suggested tension. This is acceptable, so long as the amount of turnbuckle adjustment noted above is not exceeded.

With headstay tension set as above and mast pre-bend as described, distance from top of mainsail halyard shackle (hoisted to top of the mast) to upper aft corner of the rudder support wedge on the cockpit sole is 41'8".

Ideally the mainsail should look great in moderate winds with the initial tuning.

With the Ballenger mast, running backstays should be used in bumpy seas OR when down wind boat speed is 12 knots or above.

Adjustment Tension #'s Notes

Headstay (adjustable) 1000# This initial maximum tension is used to adjust the other shrouds. This should be re-adjusted via the rig adjuster after each adjustment is made to the other shrouds.

V1 (adjustable) 1100# +- 100# This is the primary control for mast pre-bend and rake.

D1 (adjustable) 800# +- 100# This is a secondary control for mast pre-bend.

D2 750#

V2 (adjustable) 350# This is the mast tip control. This is left with less tension to allow the top to bend off in a breeze.

D3 300#

Inverted Diagonals Hand tight These should be slacked while tuning the rig. After rig is tuned as noted above hand tighten. These shrouds are not used for tuning instead only to stiffen the mast to prevent inversion. When the headstay is eased via the rig adjuster these will maintain mast pre-bend.

Ballenger Spars Rig Tuning

Adjustment	Tension #'s	Notes
Headstay (adjustable)	1000#	This initial maximum tension is used to adjust the other shrouds. This should be re-adjusted via the rig adjuster after each adjustment is made to the other shrouds.
V1 (adjustable)	1100# +- 100#	This is the primary control for mast pre-bend and rake.
D1 (adjustable)	800# +- 100#	This is a secondary control for mast pre-bend.
D2	750#	This is a secondary control for mast pre-bend.
V2 (adjustable)	350#	This is the mast tip control. This is left with less tension to allow the top to bend off in a breeze.
D3	300#
Inverted Diagonals	Hand tight	These should be slacked while tuning the rig. After rig is tuned as noted above hand tighten. These shrouds are not used for tuning instead only to stiffen the mast to prevent inversion. When the headstay is eased via the rig adjuster these will maintain mast pre-bend.