Dear Friends,

I'd like to known some suggestions on what Axi motor to use to convert a P51 .40 mustang by world models and a battery too.

Thanks,
Gaiotto

A popular .40-size warbird conversion is a 4S Lipoly of about 4000mAh, an AXi 4120/14, and a 13x8 2-blade prop, or 12x8 3-blade.

Ok Matt,

But if I put an Axi 2816-12 on my warbird, and 4S lypo and a 13X7 prop? I don´t tremendous power on my 40 size warbird, but I don´t to loose power too..What do you think about that considering that my 40 size warbird weights at about 5lb?

Thanks
Gaiotto

Five pounds is really light on this size plane. My friend uses the 2826-10 on his with a 12x6 prop and 3s4200 battery and has really good results. I think that a 4s battery would really lite it up!

I had a Global SPitfire that came out to 6 1/2 lbs with an AXI 2826/10, but with 5s 4200 TP Li-Po, instead of 4s. It pulled it along quite nicley. But If I were to do the WM P-51, I would go with the AXI 4120, just so I can go with a larger Li-Po pack on it.

Thanks Cubano 8, great photos and beautiful airplane!

But, I don't undestand one think: If the WM Mustang has the same weight of your spitfire (at about 6.0 lbs), why I couldn't use the 2826/12 instead of 4120's? I don't want to use a expensive motor and for instance a 4S lypo. What do you think about that? I want a to use a lypo from quest, did I have to use a 4000mha or I could use a 2600mha?

Thanks
Gaiotto

IF your all up weight, with battery, motor, esc, Ubec or RX Battery, servos, RX and plane come out to 6 lbs. Then I would definately used the AXI 2826, but if it might come out a little more than 7lbs, then think about the 4120.

Example, I converted an SA Corsair, that I thought was going to hit the 6-7lb range. Nope, it didn't, it ended up in the 8lb range, so the 2826 was not enough. The 4120 was.
Also the 4120 can handle more current then the 2826, so I like to go the conservative route, and not stress things.

Not to get me wrong, I like the 2826. In fact I just converted a WM supersport 40 using that motor, and it flys great. I made a thread, and posted a pic and a video, somewhere in this glow to electric forum.

So, make it as light as possible, and see what your AUW will be.

I first weigh the parts individually to get an Idea before I begin. Another tip that I can give you is, go to home depot, get some gorilla glue. If you haven't used it , practice a little 1st. I mix it with a little water so it can kick faster. It will expand(foam up) so you need to hold the parts together with tape. I apply it when it expands, before it starts to set.
It sure beats epoxy for the weight, and you can easily sand it, but practice with it 1st.

That WM supersports 40 was put together with that gorilla glue, and it saved me on some of weight.

The SA Corsair was epoxied. I'm in the process of building another one using Gorilla glue instead.

Sorry,forgot to answer your other questions.

Lets say your auw comes out to 6lbs. I like to 100watts per pound formula, so you will need 600watts. Please correct me if I'm wrong;
AXI 2826/12 max efficiency current is between 15 to 25amps, with a 40amp burst for 30sec.

so at 4s li-po which equals to 14.8volts x 25amps = 370watts
with the 30sec burst at 40amps your power is 14.8volts x 40 = 592watts

So you have a 30sec window of 592watts for take offs , full power bursts etc.

the rest of the flying should remain below the 25amp range.

Now, the time:
With a 4000mah battery:
4000mah x 60min = 240 divided by 25amps = to 9.6min of flight (at the 25amp range)

With a 2600ma battery:
2600mah x 60min = 156 divided by 25amps = 6.24 min of flight (at the 25amp range)

Now you are not going to be flying at 25amps all the time, but this is to give you an Idea of your flight times.
Another thing is you are not going to use the complete 4000mah or 2600mah, cause you Cutoff will kick in

So, I like the conservative route. Instead of 4000mah, I'll go with a 5000mah or a 6000mah, and be safe with a 10min flight, in which most of my flights are.

Question of Li-po and $$$$, Heres a link on some li-po that I'm considering, which are not bad fore the price.

[link=http://www.xushobby.com/servlet/Search?category=Li-poly+Battery]http://www.xushobby.com/servlet/Search?category=Li-poly+Battery[/link]

Thanks Cubano 8 for all this information that will be such a good think for me. I like all of your explanations and I´ll keep then in mind when I convert my WM P 51.

Regards,
Gaiotto