Attach weight + keel

[Vojta]

Hello, lovely kite people :)

I got two questions:

1) I would love to attach some lights to my kite. Lights by itself are OK, all the weight is batterry box. I  have 6 AA batteries, that is bit more than 140g. Where should I place the battery box, so that my kite will take off without problem. I have delta kite.

2) My delta kite has two options where to tie the line. See the picture. I understand that the front one (A) will provide more pull, thus better in lighter winds. Do I say it right please?

2.2) But how to approach a real situation? It is hard to lift my kite, because the wind is slow. But after succesfull climbing there is much stronger wind in 50-200 m above ground. Which one should I choose?

 

Thank you very much for any advice :)

PS: pardon my English

[riffclown]

Most often you'd place the battery box exactly at the center mass of the kite if at all possible.

To cut down on the weight, have you considered changing the batteries out for button cells? They are much lighter. A single CR2032 is 3V and has same voltage as 2 AA batteries.  That being said, The button cells are limited in power and are only a viable option for lighting LED's.

[Vojta]

Ah I how it happened that I didnt think of this by ma own...

Thank you very much!

My tests:

• my 3 AA batteries are togather 3,78 V
• a single fresh button CR2450 3V is actually 3,24 V – still not powerful enough. Green LEDs are the brightest and both red and white are barely wisible.

I found tiny 1 cm in diameter button cell. (V13GA) and it is 1,5 V. So it is same voltage as AA but for 'zero' weight. Now I dont have to worry about placement since it weights nothing! Hope I will share some pictures soon

[frob]

1) Where should I mount it?

140 grams will certainly affect the flight, but assuming you get a balance-neutral placement it should still fly in good winds. That position can be at the center of mass on the kite, or it can be on the tow point. Kites can carry relatively heavy loads, including cameras. Assuming wind is strong enough the critical factor is not the weight, but how that weight is distributed to keep the kite balanced.

As long as it remains balanced, it shouldn't harm flight too badly.

2) Should I adjust the tow point?

You can move the tow point toward the nose if you want.  It changes the pitch, the angle that the kite flies at. Closer to the nose usually makes it move forward more forcefully, up to a point.   You can choose which point to use when you are out in the field.

2.2) Should I change it in higher winds at an altitude?

I'd choose based on trial and error.  Try it with the lower setting first, point B.  If there is not enough lift, try the upper setting, point A.  If it is strong or uncontrollable, bring it back down and make adjustments.

[makatakam]

On 12/16/2018 at 4:46 PM, Vojta said:

2) My delta kite has two options where to tie the line. See the picture. I understand that the front one (A) will provide more pull, thus better in lighter winds. Do I say it right please?

This is wrong. The opposite of this is what happens and is very simple to prove to yourself. Hold the kite by the bridle with your hand directly above point A as if you were going to launch it. Then hold it below point B in the same wind speed. Which one pulls more?

The stronger the pull, the more weight it can lift.

[frob]

Said differently, one is drive, the other is pull.  They are related, but different. It is about the direction of the forces involved.  When more toward the nose the force pushes the kite forward. When more toward the center the force has more pull on the kite but less motion.

Either way, it is something that depends on the conditions on the ground when you fly, and should be adjusted based on need.  You might need more drive to lift the weight, you might need more pull, but you won't know until you try.