After recording line-pull with 4 KAP kites in Bft 1 to 5 (2 to 18kn) I have worked out a rough estimate of line-pull ratios. The ratios are expressed as line-pull (lb) to wind strength (kn)
Line-pull Ratios (lb:kn) 7ft Pirate Rok 1:1 ITW Levitation Delta 1:2 Peter Lynn 2m2 Pilot 2:5 PFK Nighthawk 1:3
Which means the line-pull (in pounds) of the Rok roughly equals the wind strength (in knots). The Levi delta pulls half as much as the Rok and the PFK one third as much. For example: In 12kn the Rok pulls at 12lb, the Levi pulls at 6lb, the PL pilot pulls at 5lb and the PFK pulls at 4lb.
Rok and PFK in Bft 1-2. Insufficient wind for the Levi delta and PL 2m2 Pilot.
The amount of pull on the line dictates which KAP rig can be used. I have started recording line-pull using an electronic luggage scale ($9 on ebay) to help with kite selection.
I have found that line-pull of about 3 times the rig weight is enough to safely lift the rig. So I need 7lb pull to lift my 1.1kg SLR rig. (Apologies for the mixed units, must start measuring pull in kg!)
Of course line angle also matters. Deltas can fly almost directly overhead. At times the delta and rig can be in perfect balance leaving next to no tension on the line in your hand and zero movement of the rig. Perfect for sharp KAP shots. It's a magical moment, hard to believe it's possible.
My intention is to build up data for each kite in a range of wind strengths.
It's early days but it seems with the 7ft Rokkaku line-pull in pounds is pretty close to wind strength in knots. For example I would expect line-pull of 7lb in a 7kn breeze.
Here are two video compilations of kites compared in Bft 4 and Bft 2.
I'll do Bft 3 and Bft 5 when the conditions permit. I have tried Bft 1-2 but the Rok was the only kite capable of staying up.
Three kites compared in Bft 2
Four kites compared in Bft 4
Eventually I'll put together videos and publish a line-pull table for each kite separately in the full range of wind strengths.
Beaufort Wind Scale
Bft 1 1-2kn Calm - Not enough to fly. Go diving
Bft 2 3-6kn Light breeze - Rok will fly, others maybe.
Bft 3 7-10kn Nice breeze - All kites will fly. Need to match kite to rig.
Bft 4 11-15kn Decent breeze - All kites will lift rigs easily. Upper range for the Rok.
Bft 5 16-20kn Strong wind - Too much for the Rok and Levi
Bft 6 21-26kn Howling - Only the PFK will survive.
To lift a camera you need a big kite with lots of pull. It also needs to be a steady flier and there are a few designs renowned for their KAP-ability.
PFK Nighthawk
The Paul's Fishing Kite (PFK) Nighthawk delta is designed to fly in winds as strong as 30kn. Most other kites would be looping and crashing by then. It has large trailing edge flaps, strong flexible fibreglass spars and a hardwood spreader. The KAP community has adopted the PFK as the strong wind specialist, but it will also lift lighter rigs in normal wind strengths.
This is my favourite kite, it just wants to fly and keep on flying no matter how strong. Tail usually not required but may calm it down a bit in strong winds and reduce overflying.
Lifting range
480g RC rig in 12kn - 30kn+
270g GoPro rig in 6kn+
NZ$140 from Paul's Fishing Kites - New Zealand
ITW 9ft Levitation Delta
For lighter winds 5kn -17kn, this big delta from In-to-the-Wind is my choice and a favourite of many KAPers world wide. It has more pull than the PFK but also starts to fly to the side and do power loops in wind speeds above it's range.
Flies at a very high angle and even over-flies in light puffy wind and hot days. Adding a tail reduces overflying and gives steadier flight. I use a 3m long tube tail.
Lifting range
480g RC rig in 8kn - 17kn
270g GoPro rig in 5kn+
US$75 from Into the Wind - Boulder Colarado
PL Pilot 2m2
This 2.0 square metre parafoil is made in New Zealand by Peter Lynn Kites. Peter Lynn is famous for making some of the world's largest kites.
Parafoils have no spars and pack up into a small stuff bag. They have strong pull but fly at a lower line angle like 50ยบ
Flies well without a tail but everyone else says they use one. May calm down side to side swaying.
Lifting range
480g RC rig in 10kn+
270g GoPro rig in 6kn+
NZ$96 from Peter Lynn Kites - New Zealand
Cody Box Kite This was the first kite I bought for KAP and it was not all that suitable. Above about 16kn it flies out to one side and power loops. It has a narrower wind range than the above kites and take more assembly time but does have good pull. KAP range 8kn - 15kn
However it is an interesting kite in the sky and attracts attention. It flies well enough within its wind range.
