Large Model Association Forum

Hi to you all, New to your site been flying for about 25 years on & off but got hooked again about 3 years ago & thanks to the bmfa & ebay well you know how it is.
in the last 3 years thow have built & assembled a lot of models for people now i want to get into the larger model side so for a start this is my 1st 1 i know its not a large plane to what ive seen at the shows, her in doors would kill me so i'm breaking her in slowley

I would like some advice on what lipos & motors to use in a T N 134" Lancaster & where to fit them & how many to use
I'm building it now i have finished the wings & about to start the sheeting the fuselage. then onto the tail & nacelles

cheers stu

Hi Stuart,
I can probably help you a little as myself and my son only fly electric now-a-days. What is your anticipated total final weight of the plane? Do you have any electric gear yet or are you starting from scratch?
Andy

No not from scratch got some on electric but not this size ive done a hangar 9 b25 & asm c130 thats it on larger stuff.
i do have 4 emax bl4030/10 motors (they say 80 size 4 strokes) that turn 16" props & was thinking putting them in with 15" 3 blade props
as for how many lipos & where to put them that would be a big help kg not a clue yet as light as i can get it

Thanks Stu

HI,
I have used the Emax BL4030 motors on a couple of planes. Not my favourite motors as they have a tendancy to flal apart. The published spec sheet is....



I have run these on 6 cell as all my batteries are 3 cell, so I always use multiples of three. From my files I recorded these as pulling about 43amps on 22.2volts so power was 955 watts. Prop speed was 385 x 22.2 = 8500rpm.

So if you are using 4 of these you have about 4kw. Trainer style flying requires 220watts/kg, sport flying 350 to 450 and 3D up to 800. So if we say 300w/kg for your plane to give reasonable umph but not crazy, then with 4000watts it could weigh 13.3kg.

You could get away with lower power/weight but it is not advisable as if you get into an awkward situation you have nothing left in reserve.

Battery size can be approximated by assuming a 10 minute flight on half of full amps. So in this case each motor takes 22amps for 10 mins, which is 3666mah. I usually find that without doing any 'crazy' full throttle flying this will give a 10 min flight and use approx 2/3 of the pack capacity.