My Bucking Buccaneer

[Pete B]

+1 with gangster....

Just a few thoughts. The 4S 3300 pack is quite big for the Buccaneer - my Black Magic, which isn't that much smaller at 60" span, flies quite happily on a 3S 2200 pack and, as much of the flight is 'climb and glide', I can easily get 20 min flights without a lot of effort. On your set-up, anything over 1/3 throttle will become a bit of a handful quite quickly, I suspect.

As gangster says, the power system is going to get a thrashing with a full throttle run - which anyway is quite unrepresentative of how you will fly her (I hope!).

I'd recommend that you fully charge the pack, set your timer to say, 10 mins on that pack, fly with a variety of throttle settings and, after landing, see how many mA you put back in. That will give you some indication of potential duration, which, ideally would be around 80% of capacity.

Pet

[Countryboy]

Thanks Pete, that sounds like a good suggestion. I was thinking about reducing to a 3s 1800/2000 pack but the reduction in weight will dramatically affect the CoG and if I add ballast at the back I may have to remove it later. At present the AUW is extremely close to the original design so I want to keep it there if possible.

Consider the full throttle trial aborted.

Mike

[Pete B]

That's good news, Mike - I can only cope with so many tales of woe each day......

Pete

[Dave Hopkin]

If you measure the current at full chat, you can work out how long the LiPo will deliver that ampage

If you have a 3000Mah Pack then it can deliver 3 amps for an hour or 30 amps for 6 mins, 60 amps for 3 mins etc

How much power you actually use is dependent on your flying style and the wind...

If you charge round like a hooligan on steroids then you will eat the capacity quickly, if you loiter round then you will stretch it out a great deal - and the stronger the wind is the more power you will use on the upwind leg of the circuit

BUT - DONT run your LiPos down past 20% as you will dramatically shorten the life of them

I assume you have a LiPo Guard meter or equivalent to see how much is left in the Pack at the field?

[gangster]

I think some of your calculations might be a little ambitious there Dave as I don't think any battery delivery 100 percent however it could be a good starting point for a couple of reasons as the average consumption will be way down so it will be Avery worst case scenario

The buccaneer will be at low throttle for most of its flight .

The current drawn in the air will be less as the motor unloads and speeds up (analogy riding a bike in high gear) load drops off and battery finds it easier to pedal ( yes and back emf is involved as well)

best plan is as previously mentioned. Set timer to three or five minutes five should be fine and fly normally and see what the battery says using either the watt meter (for reasons that I don't understand the percentage left seems surprisingly accurate) or recharge and see how much goes in.

Not a bad idea to keep maiden flight short land and inspect anyway gremlins can get in and play and loosen hinges screws etc etc

no need to have too much fear of running out of electric in the air just don't go down wind the esc should shut the motor down and let the radio work. That model will stay up for a fortnight dead stick anyway

and as Dave says once you have calculated the time set your timer so that you only use a max of 80 PC

[Dave Hopkin]

I was trying to make sure he had more than enough battery left by doing an over calculation of power consumption, especially on early flights

Anyway, you will often find in the early days, your concentration levels wont last as long as the battery and if you find yourself starting to loose focus, LAND asap or hand the control over the instructor - its amazing how mentally tiring flying is for the first few flights

[Countryboy]

I just bought a " low voltage" alarm for the old girl. It is a tiny unit that clips into the balance plug and emits an extremely loud scream when battery reaches a preset voltage. 3.0 volts at present. I have given it a test and it is still very audible at 300 mtrs over the local traffic. I should be able to hear it clearly as it passes over head. And it can be connected to LEDs too for a visual warning,

Mikle

[gangster]

Mike I think you are worrying unnecessarily about battery duration. Flight ESC are designed to shut the motor off in plenty of time to allow sufficient energy to supply the receiver and let you safely control it down Unlike boats you will not be stranded if the fan stops Isaac Newton will supply the power to land .

your model will glide well for ages provided it's not way down wind. Glow motors " go out" in the most inappropriate places and we still get them down. What you don't need is your last bit of battery which is needed by rc and servos being gobbled up by flashing LEDs and loud sirens Electric flyers rarely have issues with loss of electric and soon learn the duration of their models.

[Countryboy]

Which should I discard ? Belt ? or braces ?

[gangster]

Whatever you do keep the bike clips on

[Dave Hopkin]

Mike just make sure your LiPos are fully charged, fly the beastie for 3 minutes, land and put a battery meter on the LiPo to see what percentage your have discharged it too: then you can start to build a picture on how long you can fly on a battery for...... just err on the short side rather than stretching out to every last second