jdfoils forum posts in last 60 days

Deep Tuttle happened when race boards got wider in the late 90s. Running windward/leeward courses meant that the person who could control the biggest fin often got to the top mark first. Fin sized jumped from 2x to 4x (and ultimately up to 70) as the wider boards gave us better leverage. When the fins got into to mid 40s, we started blowing up standard Tuttle boxes. Deep Tuttle addressed this.

If you are using a fin bigger than something like 43, Deep Tuttle is highly recommended.

Not at all difficult if you have a place with a level floor and two stands the same height (i use sawhorses with a v-block on top), i also use a gauge stick to measure spacing as it is easier to get an accurate measurement than using a tape

Mount the mast with the ends on the stands
Measure the length of the mast, calculate and mark the 25, 50, and 75% station locations.
Measure the spacing to the floor at the 25, 50, and 75% stations
Hang the weight
Measure the spacing to the floor at the 25, 50, and 75% stations
Rotate the mast 90deg
Measure the spacing to the floor at the 25, 50, and 75% stations
Hang the weight
Measure the spacing to the floor at the 25, 50, and 75% stations
Rotate the mast 90 deg
Measure the spacing to the floor at the 25, 50, and 75% stations
Hang the weight
Measure the spacing to the floor at the 25, 50, and 75% stations
Rotate the mast 90deg
Measure the spacing to the floor at the 25, 50, and 75% stations
Hang the weight
Measure the spacing to the floor at the 25, 50, and 75% stations

Calculate the deflections
Calculate the average, min, and max stiffness and bend %

Done, now move to your next mast
Variations between masts and in mast orientation are greater than the measurement accuracy; easy to verify using a gauge study

Gestalt said..
The sumo is stiffer than the original no limits mast. fwiw, no limits used to make ezzy masts I believe. Being stiffer you prob need more downhaul to get it to work. Bend curve between sumo and original is meant to be the same however the stiffness changes things.

www.nolimitz.com/specs

''another argument for the correct mast or at least the original no limits used if you can find one which should be better and will give you some mix and max options of tops with bottoms..

Ezzy masts have changed quite a bit in the 20 or so years since they were made by nolimitz... they are much better now.

MobZ said..
I have Ezzy Lion's which are about 2018 i think. They get ALOT of use doing GPS stuff. Not sure if it is the sails changing or me...

-As the sail get used they stretch a little and will require a little more downhaul.

On my 7.5 the tuning mark on the sail got lost, came off. I also adjusted headcap after some issues popping it out. So i had to set that one up by sight and feel.

-there should be a sharpie mark on the sail next to where the tuning mark goes. This is put on the sails at the factory when they rig it with a load cell and is used by them to place the tuning mark.