What size batteries?

[dongle]

Just tried to get my cub in the air - it fly's like a brick!!

I think the batteries I used might be just too heavy - I had them lying around so thought I'd give them a go, but now I think I should buy something more suitable, so what do you reckon?

It's a 48 inch balsa built cub with a direct drive 6v speed 400. Not bothered about flight times, as long as they are more than 5 minutes, as long as it does not continue to act like concrete with momentum!

[soundman]

What cells did you try?

[dongle]

tried a 8 cell AA 1300mah Nimh size pack - not dissimilar to a TX pack but with higher discharge /ubbthreads/images/graemlins/tongue.gif weighs in a t 213 g's - quite heavy when the whole craft with pack weighs 600 g's..... :o

Bit daft, I know, but you know what it's like, sometimes enthusiasm out-weighs sensibility!!

[soundman]

I'm not exactly sure what out there for this sort of size plane. But people I know fly a lot of them - they use 800 mah or 1100 mah 8-10 cell packs, I think the cells are 500ar size - I Don't know what the weight is like, they might weigh the same/more.

Is the motor geared or direct drive? & what prop - might be useful to know the required current draw.

[dongle]

Just had a look at some battery pack's - there are some AR sizes that weigh about 120g's - suppose that is a considerable weight saving!

At the moment it has a 6v speed 400, direct drive with a 6x4 prop.

If I could ony find the bloomin instructions I could see what they recommended!!

[soundman]

What make is the plane? I just found about 20 different cub models.

[dongle]

It's the Wattage balsa built one -I've found a couple of places that say 800mah batteries should be used, but not in what cell size/numbers - obviously could make a huge difference to the weight!

[soundman]

I found this:
[ QUOTE ]
Specifications: Wing span (46.5”) - Length 28”) - Wing area 330 sq.in. - Weight (22.4oz) - Motor included 400 type direct drive - Radio required 3 channel with micro servos - Electronic speed controller and 7.8 cell 500-800 mAh battery also required

[/ QUOTE ]

Also:
http://www.rcgroups.com/forums/showthread.php?s=&threadid=114477&highlight=wattag e+cub

http://www.rcgroups.com/forums/showthread.php?s=&threadid=71746&highlight=wattage +cub

http://www.rcgroups.com/forums/showthread.php?s=&threadid=56292&highlight=wattage +cub

That should give you plenty of info/different setups - hope it gets you sorted :D

[dongle]

Cheers for your help soundman - Good bit of investigative skills!!

[SCOOT]

dongle, I would go with the 500ARs all the speed 400- models I have ever used have always used these cells. If you want high discharge NiMh that are the same size/weight you could try the KAN950's they will give you twice the flight time of the 500ARs'. www.onlycells.com (http://www.onlycells.com) or is it co.uk?????