Thread Tools
Sep 06, 2017, 04:25 PM
Registered User
Thread OP
Discussion

Airbus A400M electronics


I am building the 76" Airbus A-400M. I am ready to put in the batteries, landing gear etc. Before I skin it. Only issue is, is the2 x 8-cell 3300 Hi-flow NiMH batteries that the plans suggest. The seller is out of business. Anybody have any idea on where to find the Batteries? If not, what to use instead? Ideas for speed control, balance etc. would help as well. http://www.tonynijhuisdesigns.co.uk/AirbusA400M-76. Website for reference.
Last edited by Dilli83; Sep 07, 2017 at 07:38 AM.
Sign up now
to remove ads between posts
Sep 06, 2017, 08:03 PM
Up-Out-&-Gone
demondriver's Avatar
Quote:
Originally Posted by Dilli83
I am building the 76" Airbus A-400M. I am ready to put in the batteries, landing gear etc. Before I skin it. Only issue is, is the2 x 8-cell 3300 Hi-flow NiMH batteries that the plans suggest. The seller is out of business. Anybody have any idea on where to find the Batteries? If not, what to use instead? Ideas for EDF, and speed control would help as well
What is the overall weight of your A400M? And you know the 400M has props not Jet engines.
Latest blog entry: RC 737 Max 7 Maiden flight!
Sep 07, 2017, 05:04 AM
Registered User
Thread OP
It will be just short of 10 lbs. Yes I am aware it is props
Sep 07, 2017, 06:31 AM
A Day @ a Time - Matt. 6:25-34
ruff1's Avatar
What kit is it?

If it is fairly recent I would be surprised, I didn't know there were still models out there calling for nimh batteries. With nimh batteries, I would think they had to have built in a larger wing area to get the loading into an acceptable range due to the weight. I would start by taking the wing area and auw and going to one of several web sites where you can calculate the wing cubic loading.

To give you a real world example, a flying buddy of mine picked up a motor glider from the late 90s. It was designed with nimh batteries and an inrunner, and had a larger wing area. The estimated auw from the designer was 44 ounces, and once he got done it weighed 36. It effortlessly hand launched and he was very happy with the results. This is not a glider, but if you can get it lighter all the better.

I would not waste my time with nimh batteries, just go with lipos and get the appropriately sized motors and speed controllers. You may find placement of the lighter batteries will need to change to get the cg correct. Hopefully the designer has the batteries right over cg so you'll have a minimum to do there. This assumes the motors are outrunners; if they are not then there is more potential for weight reduction and power improvement but this may also affect cg if you replace them. I would be interested in knowing her "bones" weight - the weight without the batteries,speed controllers and motors. With that you can build up with modern components to calculate the auw.

Start by reporting back the auw, wing area and resultant wing loading.

There are several builders here that hopefully will chime in that know this better than I.

Good luck.
Sep 07, 2017, 07:40 AM
Registered User
Thread OP
Also, how do you get correct cg?
Sep 07, 2017, 12:52 PM
A Day @ a Time - Matt. 6:25-34
ruff1's Avatar
There are cg calculators available, just do a search. A good starting point is what the manufacturer recommends.
Sep 15, 2017, 03:47 PM
WJH
WJH
B747-400 First Officer
WJH's Avatar
3S, 6000mAh LiPo Battery, 40C Cont, 60C Burst
Sep 15, 2017, 04:38 PM
Registered User
Thread OP
Would I get 2 or just the one? Figure since the plan shows two 8 cell battery, one on each side...or just the one in "center"
Sep 16, 2017, 12:23 AM
Silent Reader
Quote:
Originally Posted by Dilli83
Would I get 2 or just the one? Figure since the plan shows two 8 cell battery, one on each side...or just the one in "center"
It's start from what kind of motor you chose, from how much max amp each would draw. From the total amperage then you could determine what capacity and discharge value of "C" is suitable, without stressing too much load on the pack.

After that you need to consider the weight of the pack, how it will affect your AUW and CG shift, also your desired flight time. Big capacity battery does not always translate well to better flight time as the heavier the aircraft become the higher air speed thus using more juice than necessary, shortening overall flight time.

For example: If your motors draw max 30 amp each at full throttle , 4 engines for a total of 120a. For this a minimum of 3000mah 40c (120a constant) will suffice. From here you can stretch out more capacity for better flight time, lesser the load (=cooler pack) by either 1 single higher capacity pack or split into 2 identical packs. With 2 packs you can plan better CG as able to spread more weight across.

Experiment which one better for your plan, you could always use object with similar weight and size as dummy battery to test around before buying an actual one.
Sep 16, 2017, 03:27 PM
Registered User
Thread OP

Wings


While I am waiting for the landing components I am working on the wings. I m a bit of a novice and having issues understanding how to form the front edge
Last edited by Dilli83; Sep 26, 2017 at 07:44 PM.


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Build Log Airbus A400M Atlas Beginner Build whizuna RC Airliners (Commercial, Cargo, Troop Carrier) 28 Dec 18, 2017 10:29 AM
Discussion Airbus a400m atlas Yash.... RC Airliners (Commercial, Cargo, Troop Carrier) 26 Feb 09, 2014 08:26 AM
New Product New A400M Military Airbus Transport from rcwarez.com rorrock Electric Warbirds 52 Jan 20, 2014 08:30 PM
Video New Airbus A400M 1/10 franck56 Giant Electric Planes 8 Mar 25, 2013 04:26 AM
Gallery Airbus A400M 1:10 HLC SHOP Giant Electric Planes 6 Jan 03, 2011 03:43 PM