aofer

hi, i bought these two kits:
[link=http://www.sigmfg.com/cgi-bin/dpsmart.exe/iflyherr/HMainMenuF.html?E+Sig]herr pitts special[/link]
[link=http://www.houseofbalsa.com/store/store-type-tem.html?item=products:k-21&sid=0001lwP6CWWLRE4rNo2C2t4]House of balsa decathlon[/link]

i think they have pretty much the same requirements since they are the same size (one requires 0.061-0.1 glow and the other 0.05-0.15 glow)
i need to choose the right system for them...
motor,esc,battery,prop and also radio gear.. receiver and servos.. but most important is the motor size
which is the right combination for me? i want something that can serve both models if possible
i was looking at this site.. since these Chinese gear is cheaper and i heard its quite good.
[link=http://www.hobbycity.com/]hobbycity[/link]

i would really appreciate your help,
thanks in advance
amit

Dr Kiwi

Being designed for aerobatics the Pitts might need a bit more power - hence the .15 cu.in - that's ~300W - and the Decathlon is more a sport flyer so .10cu.in (~200W). I wonder what size props are recommended?

Both should fly fine on 200W, so choose a motor which can cope with 20A on 3s, while spinning say a 9" prop. A 70g motor around 1100Kv should do it.

This has got good press: http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=3883&Product_Name=TR_35-30C_1100kv_Brushless_Outrunner_(Eq_AXi_2808)

aofer

so if i need 300W for the pitts and 200W for the decathlon shouldn't i take 300W for both? or atleast 250W?
so how are these chinese stuff? is it really recommended?

Dr Kiwi

These are 1.5lb planes - rule of thumb says 100W/lb or 150W/lb is plenty for other than extreme stuff - that's 150W-225W... 200W should be more than enough.

From the HC reviews it seems that some guys are happy to run it at 300W+ [some of them need Math 101 since their V x A = W does not compute!]. It will depend on what prop suits your planes - if you are limited to 9" then you could go up in Kv since this one is okay with 10" -11".

aofer

can someone recommend me a whole pacakage?
i need motor,esc,battery,micro receiver,micro servos,prop and charger...
from that hobbyking site
thanks

Dr Kiwi

Tell me what size prop is required, and I can do it.

aofer

i'm not sure which prop i need,
one that will make these planes fly well and be able to do aerobatics

aeajr

My Feedback: (2)

Everything you wanted to know about electric flight
http://www.rcuniverse.com/forum/m_7100376/tm.htm

As part of your general education, this might be helpful.


If these are 1.5 pound planes, these packages might be a good fit;

Combo 10, combo 15A, combo 19A depending on the performance level you seek
100 watts per pound will give you good aerobatics. Above that will just add to your power reserve.
http://www.maxxprod.com/mpi/mpi-264.html