Great Planes CAP 580 Giant

[tIANcI]

I am thinking of moving to a 100cc EP plane since I do have quite a few 5S packs now. This plane came to mind as the LHS is trying to push it off really cheap and I am looking for a show plane. Not really for hard 3D flying but more for scale aerobatics with good power for verticals. Guess that sets out my expectations.

I am thinking of using an AXI 5330D motor, I find that this will allow me to run on multiples of 5S with ease off 2 90A HV ESCs (which is cheaper than one branded 200A HV one). My estimate is that the motor will easily haul a 26 lbs plane since Model Motors claim that the motor will 3D a 13 kgs plane.

My concern after seeing the plane is that the motor box is an extention on the firewall and that means with a full firewall I cannot push the packs all the way to the front to replace the weight of a 100cc engine.

Anyone knows where I might be able to find anything on the one that was flown at SEFF? I think 1 was at one of the SEFFs.

I was also informed this plane was flown at one of the XFCs using a BME 115, anyone got a link to some article or video of this? Thanks! All input is welcomed!!!

[GordonTarling]

How do you plan to run one motor from two ESC's? ESC's can't be ganged up to get the capability that you need. Not sure that any multiple of 5S will work in that plane, IF it really needs the equivalent of a 100cc engine to fly well. At 10S, you'll be drawing VERY high current from the pack, so you'd need top-notch batteries to cope, but you'll still get shorter flying time. If you went to 15S, I'm not sure there's an ESC yet available that could cope, the best that I've seen so far is an ESC for 14S. Give us more details of the actual model you have in mind and I'm sure you'll get lots more help!

[appleflyer]

hes going to use the AXI 5330 double. so that how he can use 2 escs

[Geoff Dryer]

It looks like a single AXI 5330 is a 2000 watt motor so would 4000 input watts be enough for a 100cc plane? I think that any aerobatic plane in the 100cc category will need a little more than 4000 watts.

If you are looking for an inexpensive solution then you might consider a Hobby City motor. This is the thread on my conversion of the 80cc Hangar 9 Sukhoi.

http://www.rcgroups.com/forums/showthread.php?t=933906

The 180Kv version of the 80-100 motor should produce pretty good htrust on 10S. I would run a 10S-2P battery configuration.

[R/C Dallas]

It looks like a single AXI 5330 is a 2000 watt motor so would 4000 input watts be enough for a 100cc plane? I think that any aerobatic plane in the 100cc category will need a little more than 4000 watts.


Although the double axi would not be my choice, the Reaper 70 or 85 would be worth considering, but 4000W equates to almost 150W/lb at the upper advertised weight of 28lbs AUW which should provide decent sport aerobatic performance. The biggest obsticle IMHO will be getting the weight of the power system far enough forward for a decent CG. I read where the DA-100 comes in around 7.5-8lbs with all the goodies attached and full fuel. That should give you the ability to use decent sized packs for respectible flight times. I think it just might be doable.

[tIANcI]

Thanks for the input guys ... yeah like what Dallas says, how do I get 8 lbs on the nose? The engine is about 6.5 lbs without mufflers etc. Maybe I can sling a set of 10S under the motor mounting box and another set to be located in the fuel tank section. Its doable for sure.

Motor is 3.5 lbs with the standoffs
Batts are 1.25 lbs each (2 packs up front means 2.5 lbs min)
ESC is about 0.4 lbs each, that makes it about 1 lbs for 2 ESCs with connectors

Guess I can put about 7 lbs up front and another 2.5 lbs in the fuel tank area with 2 more packs.

As for power I know the 5330 can be pushed to easily 70A-80A and many have done it before. So we are talking about in the region of 2,800W per motor. That gives us around 5,600W ... I would be happy with 5KW at a min for such a plane. So on paper its about 175W/lb. Sounds pretty decent if its not for 3D. :)

The only reason I am looking at the 5330D is that I need not spend so much on ESC and the same motor was used to haul a 33% H9 Edge 540 and they propped hang the plane too. :)

[GordonTarling]

Sorry - didn't realise that was the double Axi that you were considering. In my experience, it's always more efficient to use one motor per prop. There's now plenty of choice in 5kW motors out there without having to gang motors up.

[tIANcI]

Gordon ... I am thinking that the ESC will cost a bomb and I am running on multiples of 5S, I think 15S will be nuts for me if each pack is a mere 20C and 25C 4,900 mAh.

For a 15S set up that pulls 5KW its about 100A, that would mean I am pushing my packs to the max and also it will lower my flight time. I did see some 14S set ups but they usually run about 7,000 mAh to 9,000 mAh packs if I recall.

So my answer to all that is the AXI 5330D.

[GordonTarling]

tIANcI - I do see your point about the batteries, but I guess there's pros and cons for each approach. If you're planning to run each half of that 5330D on 10 cells, then you're going to need 4 equally matched 5S packs in total. Whatever you do to achieve that sort of power level is going to be expensive and complicated, so I guess it makes sense to choose what best suits yourself.

Regarding your CG 'issue' - I'd suggest seeing if you can fit the packs inside the cowl, in front of the firewall.

[tIANcI]

Gordon ... I got the packs at the moment ... I have 8 packs of 5S 4,900 and am getting like 4 more. :) They are also used in pairs. With 2 ESCs I only need for them to be 'equal' in pairs only right? Or must it be in 4s? :(

[GordonTarling]

tIANcI - With the two ESC's, you need the packs to be well matched for those that you connect in series to give you a 10S pack. Naturally, you'll need two like this, but as far as I'm aware, they won't need to be connected together. What you DO need to watch though is that both '10S' packs are also fairly well matched, as you wouldn't want one ESC cutting off at LVC before the other.

[tIANcI]

Gordon ... I get what you mean! It would be kinda interesting to see how a plane that is powered with 6KW suddenly try to fly on like 2KW! Looks like things are never that simple. I need to check the resistance of my packs. Perhaps it might assist a little if I do not reach LVC? :)

[Keithf]

tIANcI, both 10s packs should be connected in parallel, for safety. If you don't have them in parallel, then if one motor is drawing more amps than the other (motors may be slightly different Kv, motor timing may be a bit out, one Lipo pack may be stronger than the other, etc) one pack will dump before the other. If this happens, you've got big problems. The one remaining motor will be trying to spin a prop that is WAY too big for a single motor to spin. Current draw for the remaining motor will increase enormously, and you'll either cook your motor, ESC or LiPo. You just can't allow it to ever run on just one motor.

[tIANcI]

gotcha Keith ... thanks!

[The Reaper]

hey Dallas

i would go with the gr855cc she can run 6500 watts with out even breaking a sweat. that would be arround 45lbs of thrust on 12s.

scott

Although the double axi would not be my choice, the Reaper 70 or 85 would be worth considering, but 4000W equates to almost 150W/lb at the upper advertised weight of 28lbs AUW which should provide decent sport aerobatic performance. The biggest obsticle IMHO will be getting the weight of the power system far enough forward for a decent CG. I read where the DA-100 comes in around 7.5-8lbs with all the goodies attached and full fuel. That should give you the ability to use decent sized packs for respectible flight times. I think it just might be doable.

[tIANcI]

Scott ... nice video ... only issue is for me it is a set up in the multiples of 5S and am not too keen to get one of those 200A ESC that costs a bomb. Your motors look interesting though ... kinda premium too in price.

[PORKCHOP]

Sorry - didn't realise that was the double Axi that you were considering. In my experience, it's always more efficient to use one motor per prop. There's now plenty of choice in 5kW motors out there without having to gang motors up.

Just looked at this motor, very cool. You can run it with one prop driven by both motors or configure it for contra rotating. 6000w burst. Very light for the power it seems. Even if it's not the best motor for this app it will be awesome for something.