500mm or 550mm blades for Best flying time ?

[Invité bmichels]

I flew today for the first time the Hurricane 550 that I bought on EBAY. It fly NICE !

I got 7" hovering with the 2x3s2200mA . So, I will try tp fly 6" max in order to be easy on those used Lipos.

- I use 500mm wood blades. Is there any interest to go for the "short boom upgrade" ?

- I use the stock 850Kv Motor, but I will puchase BIGGER lipos, something like 6s4000mA or 6s5000 EvoLITE. Considering that I am still looking for long flying time, and that I am FAR from doing 3D? what is best: 500mm blades or longer 550 mm blades ?

If I upgrade to 550mm, do I need to change the motor or will the 850 Kv be OK ?

If I upgrade blades (and motor ?) will I get less or more flying time out of my big Lipos ?

In other word, why is't everybody using 550mm blades instead of 500mm ?

PS: I am still looking for a nice and LIGHT scale military fuselage for this Hurricane. Idealy a HUGUES 500. Can one recomend one to me ?

thanks

sincerely

[Invité]

Hi Bmichel,

It is funny to read some english in this thread !

About longer flying time, a lot of topics deals with that !

What I can tell you from my own experience (I've been flying with my Hurri for 9 months) is that 3 main factors does effect on your flying time, considering you use the same batteries :

• 
  [*:11niyuqw]The motor

[bLOCKQUOTE]Z-motors are much appreciated : Z-20 980KV or Z-20 1470KV for sport flying and Z-30 1100 KV for 3D flights.

Z-20 1470KV will give you the longest flying time (more effecient than the 980KV),

http://flying-hobby.com/catalog/index.p ... 184&page=2

New Scorpions motors start to be used on the Hurri as well : HK 3026 Series :

http://www.espritmodel.com/index.asp?Pa ... rodID=8407

The problem of the stock Gaui motors are their bad efficiencies : get very hot and shorter flying time.

[/bLOCKQUOTE]

• 
  [*:11niyuqw]The blades

[bLOCKQUOTE]Carbon Fiber blades will defenitly give you longer flying time compare to the stock wooden blades (at least +1min on hovering).

Having bigger blades (550mm) will not help you so much because they are heavier and need more power from your motor. The only interest, is to lower your head speed.

500 mm seems to be the best compromise for this heli.

[/bLOCKQUOTE]

• 
  [*:11niyuqw]Head Speed (HS)

[bLOCKQUOTE]Depending on your type of flying, you have to determine which HS you want.

The higher HS you have, the shorter flying time you get !

After reading a lot of threads and with my own experience, I would recommend :

• 
  [*:11niyuqw]HS = 1700 RPM for hovering
  [*:11niyuqw]HS = 1850 RPM for sport flying
  [*:11niyuqw]HS = 2100 RPM for 3D

When you know the HS you want, you have to adapt your gears to makes your motor spining at the maximum speed (the higher, the best motor efficiency).

In my case, I had to change the stock gears with : 13T/60T + 19T/61T.[/bLOCKQUOTE]About battery wheight : You can use bigger lipos (if they fit with your canopy), but you will burn extra energy due to the overweight of them.

I would recommend some 3300 mA/H 25C discharge : Zippy H from this site are cheap for good quality : (12min of hovering and 9min of sport flying)

http://www.hobbycity.com/hobbycity/stor ... sortlist=#

Personaly, I bridged the gap and use now A123 batteries (8S). Shorter charging time (15 min) and far longer life time (more than 1000 cycles) !

Another tip : this thread is one of the best to find tips about the Hurricane 550 :

http://www.helifreak.com/forumdisplay.php?f=80

I hope my answer taught you something !

Regards,

Sonny.

[Invité fanedi]

pas mal la réponse en tout cas !

[Invité bmichels]

merci de vos réponses. Maintenant que j'ai mis un Z20 980, je vais donc essayer différents rapports de démultiplication.

Est ce que l'upgrade "torque tube" de GAUI ( transmission AC par barre plutot que courroie) fait gagner de l'autonomie en réduisant les frictions ?

par avance merci

PS: est ce qu'il y a des palles 500mm a recommander pour leur rendement (PAS d'accros pour le moment)

[Invité]

Bonjour,

Pour les pales, celles en carbone noires de Gaui sont très bonnes (meilleures que les blanches).

Pour la transmission de l'AC par cardan, je ne l'avais jamais vue !

Selon moi, le principal avantage de cette transmission, c'est effectivement la diminution des frottements, et donc le gain en autonomie.

L'inconvénient majeur, c'est le cout de la réparation en cas de crash !

A chacun de mes crashs, j'ai du changer le tube de queue, mais jamais la courroie...

Cette option est en tout cas une bonne nouvelle pour le Hurricane !

Sonny.