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Old Mar 24, 2009, 04:23 PM
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I need help, please, for new plane

hello my name is David from Spain ( I am sorry for my inglish )

I will build a twin-engine plane. ( bimotor )

I need to know how to connect the two motors at once.

I need 2 ESC??

I need 2 receivers??

Please help me

I hope your reply

Thanks for read this post
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Old Mar 24, 2009, 04:32 PM
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bazuka's Avatar
Longmont, CO.
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davidtb,

If you are going brushed then you will need only one ESC, as long as it can handle the amp load of the motors.

If you are going brushless you will need two ESC.

Only one receiver required since you can use a "Y" connector, see attached picture from a GWS manual.
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Old Mar 24, 2009, 04:46 PM
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Great reply and help Bazuka! GWS Manual picture great way to show how to. Just make sure you do enough research brushed or brushless as to matching amp rating between motors, ESC's, and battery.

Good luck, twins are my all time favorite followed by biplanes.
Freddie B.
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Old Mar 24, 2009, 04:48 PM
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Thanks very much for the reply

ok I use brushless motors

I understand I need 2 ESC, and use only one conector for the two ESC

is correct ?
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Old Mar 24, 2009, 06:43 PM
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Yes. You need to use a non reversing Y-connector. Also, do not forget to disable the BEC on one of the ESC's or you could fry the reciever! (the BEC is what powers your radio system on an electric aircraft). You can pull out the red wire on one ESC, and tape it back with electrical tape to disable it.
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Old Mar 24, 2009, 07:03 PM
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ok thanks very much
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Old Mar 25, 2009, 04:38 PM
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Rock Hill, SC
Joined Oct 2002
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Quote:
Originally Posted by Xpress..
Yes. You need to use a non reversing Y-connector. Also, do not forget to disable the BEC on one of the ESC's or you could fry the reciever! (the BEC is what powers your radio system on an electric aircraft). You can pull out the red wire on one ESC, and tape it back with electrical tape to disable it.
Thanks for this info. Could you clarify what you mean by a non-reversing Y-connector? I have used Y-connectors on dual aileron applications (one servo per aileron), but have never tried a dual brushless motor set-up before, something I need to learn for a pending project.

Thanks.

RD
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Old Mar 26, 2009, 01:10 AM
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Most 'Y' harness connectors are non-reversing, in other words all leads of the same color (+/-/signal) are tied together. A reversing 'Y' as stated reverses the leads so the servos will move in the same direction as needed in dual elevator servos or flaps where you do not want to flip the servo around (or in ailerons we put the horns both facing in, or facing out).

Simply the 'Y' harness is for the servo lead ends from the ESC so they can both get signal from the throttle channel of your receiver. The BEC function sends power to the receiver so you do not need a seperate flight pack to power the radio function. The reason to disconnect a 'red' lead to one ESC is so two BEC functions are not both sending power to the system.

Not to get too confusing, some ESC's like Castle Brand CAN have both red leads connected causing both BEC functions to remain active, actually increasing the amps to the receiver with no harm (2x 3 amp BEC actually puts out 1 1/2 the rated amps, or approx 4.5 amps). I do not know if other brands work the same, and probably would take the standard advice and remove one red lead! Bect way is to lift the plastic tang in the connector with a #11 blade and pull the lead out, tape it, and it remains to be put back in later if you need the device for anotherr project. Often the suggestion is to cut one lead, but I can't cut anything if it is going to destroy it's intended function for later!

If your twin project is large enough to handle the extra weight, the best way is to disconnect both red leads to the 2 ESC's (you will still use the 'Y' harness to get signal from the RX) and use either a seperate flight pack, or the new regulated BEC devices. The reasons for this are many, including the some rare instance where a glitch may show up in the system that defies explination. Further a ESC with BEC is only good up to 3 cell Lipo, or 10 cell NiMh/NiCd. The higher voltages are too much for these tiny devices to handle. Now we would have a system where you could go to larger cell count (as long as the ESC is rated for higher volts), using less amps, and acheiving longer flight times or smaller battery size.

The subject could encompass a book I'm sure, but in reality it is done every day quite simply. Enlarge the GWS drawing in post #2 above, study it carefully and I think it will all make sense. The GWS picture just doesn't show the 'Y' connector clearly (3 wires) but the concept is right on. Just remember that 1 red connector rule, 3 Lipo or less, and you should be OK.
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Old Mar 26, 2009, 10:23 AM
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Freddie:

Many, many thanks for your tutorial. It all makes very good sense. I am favoring the idea of a separate battery pack or one of the UBC devices for the twin project. This is all very much in the distance at this point, but the information you have provided is most valuable. I am considering the use of a 2-cell Lipo for the separate battery pack, provided I can find a way to knock the voltage down to around 6V to accommodate the servos.

I was surprised to find an ESC that was capable of handling 2 - 6 Lipos. It's a Venom V-Series 60 amp unit, used on my biplane, powered by an E-flite 32 brushless outrunner, on a 4-cell 4000 mAh MaxAmps Lipo pack. I thought I would need a UBC of some sort in order to get the volts needed to spin the EF-32 properly, 11x7 prop, pulling the 4.5 lb AUW of the plane. Then I read the instructions for the Venom ESC and was surprised at the specs. The system works fine!

Thanks again for your info. Feel free to "teach" anytime you want!

RD
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Old Aug 06, 2009, 07:41 AM
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Hello

grettings from venezuela, if somebody can helpme, i need plans of any twin motors (bimotor), i want to built one these.

Thank

my email: jamodu75@gmail.com
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