Hi People


Does any body know how much current is drawn from the receiver batt at any given time during a flight?
I realize this depends on amount of servos, type of servos and the style of flying but just an average will do.
My challenge is I am building a FB f-18f and I am trying to keep the weight down, So if i run one lipo and regulator,
What size regulator must i use ?

Regards

Anthony

The Powerbox Royal reports a max current draw of 8.2A in my Skygate Hawk with 8 x 8711s on board.

Rgds,
Mark

and a pitty 300 mah on a Elan with 10 servo,s ....

I have a PA F-16 and an F-15 each have 5- 7 servos...8611s on the stabs, 9411s on rudders and various std servos on non critical controls. My average draw is 350-400 mah per 6 min flight. I take great care in setting up controls to avoid any binding which will consume great gobs of power with digital servos. Get a amp meter to set up the controls to minimize power usage.

Anthony, your F-18F will tip the scales at close to 40 pounds when ready to take off.

Add a good regulator and a battery setup. A few ounces/grams is going to go along way in the electronics department. Using LiPo's is a great idea and use a smart fly turbo reg. You'll be cash money!



Raf

I wouldn't run just one battery pack on a jet just for the backup reason alone. Typically a 2cell lipo will run some where around 8.5v or so right off the charger so you will need a regulator that will bring it down to 5.6 or so. (unless you are using servos rated for the higher voltage) Also, you should worry about the peaks of a typical flight. If I remember correct a typical flight of scale jet like that might peak several times in the 10-15amp range depending on style of flying but the average consumption is around 2-3amps through out a flight. I would at least run 2 2400-3000mah or so 5cell packs if using nimh or nicad. If you choose to go Lipo I would run 2 2cell 2400-3000 mah pack with both packs on regulators.

You will have a good bit of time, labor, and money tied into this jet. Last thing I would cut back on is batteries/servos/switches. Optimally you would want to run a power distribution setup like POWERBOX etc etc. The are other brands available but most of them have built-in regulators, dual battery support, multiple servo support per single channel, and complete redundancy for a minimal weight gain.

You will have quite a bit of servos in this jet. 2 ele, 2 flaps, 2 ail, 2 rud, 1 ster, 1 brk, 1 retr, 1 dor cyl. That is a minimal. BE SAFE NOT CHEAP

Hi Raf

Thanks for the reply but let me tell you were I am coming from, My eurosport and L-39 ran with two 5 cell nicd pacs this was about 400g ( 14oz) so i am trying to half that.
I am looking at getting a schults rx batt with built in regulator (136g) But it is only rated at 7A nominal and 10.5 max current draw, Just wondering if this will be enough.

I realize that 260g wont make a huge difference but if overall i can shave off 1 kg then all the better.


regards

Anthony

You are switching LiPo's for NiCad's. HUGE difference there.

Again, I don't think you'll notice it though, your jet will be heavy. Big deal, there are tons flying out there and yours will fly great like all the other ones.



Raf

Just to clear this up after a PM, the 8.2A is not what is consumed per flight!! That is around 550mah per 7min flight. The 8.2A is the peak current draw during the 7min flight. Probably full flap and holding in up elevator I'd guess during approach?

Rgds,
Mark

you can run 2x Duralite 2150 Li-Ion (110 grams each) and a sensor switch (35 grams) and have a very light weight redundant system.

Hi

I got the same plane - FB F18F, running 4 Futaba 9156 and 3150, plus valves, wheel servo, etc mannaged by a Weatronics. I got peaks of 10,5A and an average of 350mah per 6 min flight.

I run 3200mAh lipos for receiver and ECU and a 1800mAh for backup receiver.

Regards

Nuno

Not sure what peak amps are, but i only put in about 600mah per pack after 3- 10 min flights in my eurosport using dual 2s1p 2300mah A123 packs.

If your worried about amperage draw, run dual 2s1p A123's. No regulator needed (as long as your servo's can handle 6v).. And 5 minute balance charging times per battery at the field are nice

Hey Mark

Slight thread creep I know but did you ever get a max current figure for the 260 before it sold?

Phil.

Phil,

No, 'fraid not but I wouldn't be surprised to see 15-18A maybe?? 12 x 8711s being hammered in 3D flight are going to pull some big amps!! I seem to remember somewhere that Quique Somenzini pulled 17A a flight??

Sorry, back to jets..........

Rgds,
Mark