I'm building a CBM a-10 with twin electric ducted wemotec midi fans. What I would like know is if 2 of these powerplants will be adequate to power the plane (it will have full retracts)

And if so, how do I control 2 motors - would I just use a Y connector, plugging both speed controls into the receiver?

Any help is GREATLY appreciated!

From the website:
LiPo Propulsion Pack with KOK1500HC-2S3P, FMA ASC30 Speed Control, and Speed 600 (7.2V) Motor.
Ratings: 7.4 Volt Pack
Outputs: 4500 mAh Pack will Handle up to 36 Amps Continuous Current
Applications: Speed 600 Powered Electrics - Direct Drive or Geared.

If they are brushed motors, you can simply wire them in parallel to the output of a single speed control. Bear in mind that this ESC needs to have TWICE the normal rating, because two motors means twice the current going out to them. If, for example, one motor drew 10 amps, the ESC would need to be rated for at least 20.

If you already have two ESC's you can connect things with a Y-cable, as you suggested, but I think you have to remove the red wire (whichever one carries +5v) from one of the receiver connectors on one of the speed controls. The receiver cable carries power to the radio from the BEC (battery eliminator circuit) in the speed control, and you don't need twice the normal power to the radio- just to the motors!

Steve

I am going to say no, 2 550/600 size brush motors will not fly this plane the way your setting it up. Combat Models makes a heavy plane to start off with and they suggest to glass it as well, which you would definitely want to do if for the durability needed to handle the extra weight. There's alot of extra weight involved in the retracts alone. Every 1/2 ounce is crucial, your battery pack weight alone will be near 3 lbs if you use nicads, very expensive if you get the near 2 lbs of lipos needed to service 2 550/600 brush motors. This plane could easily reach 8~10 lbs going this route. Even if it did fly, it would be slow and always near stalling, not able to perform aerobatics, not able to gain altitude, a poor flyer all around.
A better option for twin EDF would be to go brushless. These motors are smaller, lighter, more efficient and much more powerful. They use smaller, lighter batteries so your weight is drastically reduced and along with that increase of power. This will be rather expensive, so thats something to consider.
Now if your dead set on using twin 550/600 motors, you will have to go minimums. Fixed gear, but most likely no landing gear(a belly lander) which is rough on the plane if your not flying on lush grass. For the belly lander version, you would need to glass the the bottom of the fuse with a few extra layer and especially on the wing landing gear fairings, along with any other contact patches. Also, you would still want to go lipos, the less weight will not only help this plane fly better, but also cause less damage while belly landing.
The last option would be to just get a single Jeti 45/3 or an AXI 2820 or 2826, and mount it on the back where the glow engine was suppose to go. These motors perform like glow engines ranging from size .40 to.60, there are even bigger AXI motors available, but you may have to use 3 or 4 bladed props. This way if you went with lipos, you could really build the A-10 however you wanted.

Based in the UK we CAD designed a 2m wing span A10 for this seasons displays. AUW is 12lbs, powered by two Hacker B20 18S brushless motors with 2 master controllers each running off 16 3000 nicads. We use these to balance the c of g of the model as most weight is aft of c of g. Thrust is 5lbs per motor with the midi fans - make sure you use the latest 5 blade versions from Jepe in holland the earlier Jet Factory 7 blade versions do not give as much thrust. Full retracts and flaps model flies true scale with all of the flight characteristics of an A10. Flight times approx 7 mins. We now have the 1/6th scale version being produced for next season. Details available if required. Good luck with your project its a great plane to fly.

I too am contemplating a build on one of these, but I plan on using 2 Himax 2825/2700 brushless turning 5.5x4.5 props at the back of the engine nacelles. I have weighed the bare airframe with no glassing and it is only 16 ounces. I am going to make new landing gear out of smaller music wire and do very minimal glassing using thinned down water based poly instead of the heavy epoxy like in the directions. For servos I will go with Bluebird 380 max mini servos that are metal geared and have 60 ounces of tq. and only weigh 18 grams each. The wing will have a .157" carbon spar tube run end to end and each servo will mount in the bottom of the wing linked directly to each aileron and flap.

Am I wrong in thinking that if built extremely light,3 to 4 lbs. with a 3S2P Kokam 2000 lipo pack is attainable? I see no reason to build it as heavy as the glow version at all. E-Calc is showing around 40 ounces static thrust from each motor and a pitch speed of 99 MPH . This is a much cheaper way to build it than going the ducted fan route and the props won't be seen while in the air.

Rick

Any progress??? i want to do the same with my CBM A-10, twin pusher props but i can't find any motors that put out at least 300 watts of power on a 5-6 inch prop. any suggestions??

Kyle