Headspeed

[troasb]

I am now building my E7se. I would like to have more than the usual 4 minutes flying time. What headspeed should I go for if I want to get around 6 minutes flying time? And how much power will I sacrifice then?

I run a Kontronik Pyro 750-50L motor and Optipower 6S 5000mAh 50C batteries.

[Grimmy]

I'm running something like 1650, 1800, 1950, and I can get 6 minutes at 1950.  That's sport flying.  I also use a mAh counter, so I've ditched my timers.  I've done the same on my E5s and gone to 8c and am around the 6 minute mark.

[troasb]

I'm running something like 1650, 1800, 1950, and I can get 6 minutes at 1950.  That's sport flying.  I also use a mAh counter, so I've ditched my timers.  I've done the same on my E5s and gone to 8c and am around the 6 minute mark.

Thank you for your useful reply. That is good news that I can run up to 1950 headspeed. I am also running a Kontronik Kosmic esc so I am going to use a mAh counter too.

But I don't understand what you mean by 8c?

[Grimmy]

On my E5, I am running it on 8 cells (2 packs, 4 cells each) and running a 890kv motor.

[troasb]

On my E5, I am running it on 8 cells (2 packs, 4 cells each) and running a 890kv motor.

So you went to 8S to improve flight times? What capacity do you use on the LiPo's?

[Grimmy]

Yes.  I am running 2 Pulse Ultra 3700mAh 4 cell packs:

http://www.helidirect.com/plu45-37004-pulse-lipo-3700mah-14-8v-45c-ultra-power-series.html

I'm running a lot lower headspeed then most too.  I think normal is like 1400, IU1 1600, IU2 around 2000 (maybe 2050).  If I stay in IU1 I can get around the 7 minute mark.  Depends on how much I beat on it.

I've toyed with going to a 12c setup, but well it'll have to wait till next year if I do and I'd have to see some good gains to do so.  If I just bought the E5 and was building it for the first time, I'd give a good consideration of going to 12c, especially if I stretched it right away.  Stretching it and staying with the 4025-1100kv motor just killed way too much flight time for me.  Plus going to the 2 pack setup, each pack is around $70 and if one goes bad I can replace the one (I'd replace them both due to age) but it's nice to have that option.