Hello, I make a query of a rookie that just starts in this:

I built a comet NASA 5 of 2m and 4m for traction buggy. For the lines I bought 70m dynema (for brakes I have the same amount of Dacron). I was thinking of dividing it into sections to have lines 20m, 10m and 5m, to opt for either of them according the wind, the kite (2m2 or 4m2), the site, etc.
My question is (I know that the more longer lines is more flight window) this split would stupid? I should split it in other lengths?

Thanks and sorry if it's a silly question

PD: if I did this, there would be no problem in joining the lines between them with ties if I need longer lines?
:duh:

Sounds like a good plan to me. I usually fly my Nasa Stars on 20m lines and find this suits nearly all situations. A 10m set would be handy for areas without much room. I usually fly them on a 3 line configuration (2 lines and a light line connected to the nose as a safety/depower) On a couple of occasions I've rigged them as 4 line kites and don't recall there being much force on the brakes so dacron might be ok for brake lines.

You should easily be able to use a 'larks foot' to join up the lines for a longer set or even use some pigtails between lines if need be.

Yes, you will want to sleeve the lines. Not using sleeves will dramatically reduce the strength of the line. Sleeve kits are small and light so not expensive to have mailed to you if not locally available.

5m, 10m and 20m sounds like great set up for parking lot to beach/field /frozen lake use flying .

Best to use same material for all fly lines and best if Dynema for long lines because of strength to weight ratio and long heavy lines 'sag and drag'.

For 5m you could use all Dacron(all 4 lines-same material) ..... if it's right strength. Get line rating info. When you're flying such short length line, heavier lines don't add much overall weight...... long lines of heavier weight- not the case.

Typical Dynema power kite fly lines are 200 kg for 'top line' and 100 kg for brake (or bottom lines) on your handles-if you're flying your Nasa as 4 line. you should have similar strength rating for any kind of line you use, be they thin or thick lines of different materials.

Again use all same material for all 4 lines. If you do down turn/upturn multi-spins where lines cross and rub together, having two different materials may mean one line may cut 'into' and wear on another line much faster.... or this is what a veteran flyer told me way back, I believe.... ?

Maybe another can speak on this.... cause i'm just not sure..

Pics of your Nasa kite?

Adding sections together will work but keep in mind the points where you connect them will add wind resistance which can affect the flight characteristics to a great degree.
What the others said also...
I would set up different line sets to use instead of adding them together.

I've concluded long time ago that having brake lines as 50% strength of power lines is an unjustified overkill causing unnecessary drag with greater effect than a couple of joints on the lines. In my estimate 10% would be more than enough. For that reason for brake lines now I just buy a spool of fishing line Dyneema, something like #100 or #150 which is again more than enough but easier to handle and less stretchy than something thinner (around 15$ or so for 500m @ Amazon). I think this is a better solution than Dacron - thinner for similar strength. As for the brake lines supplied with sets ?. On several kites including Nasas I used them as power lines. Never broke one yet. I don't jump so it would not be a big deal if I did.