Hi everyone, currently scratchbuilding an epp and coreflute Arado 234, which will be powered by a twin pusher configuaration. Never built a twin before but I have two complete, Identical power systems from another plane that i have since upgraded to a lipo setup. It is an ewatts r2212 1500kv brushless motor with an 18 amp esc and 11.4 v 1000 mah nimh. I bought another complete set up as a spare because the plane it was on was being continally hammered into the ground etc and I thought a complete spare power train might be needed. They both managed to survive and were just sitting around not being used. My question is this -Could I just hook up both esc's to the throttle control via a y-connection and simply use them as is? I realise that I may have to limit my time a little just in case on battery runs out before the other, but apart from that I can't see any problems -I'm just trying to use existing equipment without adding to the cost. Cheers....
It's pretty much that simple. The only thing you'll need to do is disconnect the red wire from one of the ESC's if they are BEC equipped. You do not want both trying to feed power to the RX.
Or you could disconnect both BECs and use a separate BEC unit or battery pack.
EDIT: When you disconnect one (or both) of the red wires don't cut them. Just carefully remove the wire from the plastic plug, wrap it in tape or heat shrink to protect it from shorting. That way you can re-use the ESC later and not have to splice any wires.
Support the entire Constitution.
Not just the parts you like.
Thanks for the info Twmaster and Gyrocptr, Just two more questions ...What is the the best way of removing the red wire from the esc? It seems fairly secure in there. Do I need to cut away the plastic somwhere or can I push it out from the other end etc? Should I practice on some old servo leads that I have? And wiring the batteries in parallel- do you suggest making up some deans connectors so that the negative wire goes to the positve wir on the other battery and the remaining neg -and pos+ wire are connected to a single connection which then y-connects to both esc's? I like soldering and fabricating custom stuff so I hope this is what you mean Cheers...
If you have a voltmeter, you may not need to disconnect the red wire at all. Hook up one system and check how much voltage is supplied to the servos via the receiver connection. Then connect the same battery and receiver to the other ESC and check the voltage again. If the supplied voltage is within 0.1 volts for both setups, you can use both ESC's unaltered, and you'll have twice the available amperage to run the servos. Since they are identical ESC's, the difference might be too small for your voltmeter to read, unless it goes to 2 or 3 decimal places. I have setup 2 multi's like this, and the measured difference in voltage was 0.002 volts, on the worst one.
I got this info from a tech at Castle Creations, by the way, and they know speed controllers!
Dennis Fishback AMA# 162410 AKA# 120592
If it flies, I love it!
... wiring the batteries ... do you suggest making up some deans connectors so that the negative wire goes to the positve wir on the other battery and the remaining neg -and pos+ wire are connected to a single connection which then y-connects to both esc's? ...
No, what you described will connect the packs in series.
To connect in parallel:
Red (+) wire from battery-pack-1 connects to red wire from battery-pack-2. Black (-) wire from battery-pack-1 connects to black wire from battery-pack-2. Red wire from ESC-1 connects to red wires from battery packs; black wire from ESC-1 connects to black wires from battery packs.
Red wire from ESC-2 connects to red wires from battery packs; black wire from ESC-2 connects to black wires from battery packs.
You can use 2 Deans connectors (male) if you stack the connectors and do all of the soldering/interconnections at the connector-stack.
You can use 3 Deans connectors (2 male, 1 female) if the single female connector is configured to join with a 3rd male-connector that is soldered to the wires from the ESCs.
You can use 4 Deans connectors (2 male, 2 female) if you want each ESC to be detachable with its own individual connector (3rd and 4th male connectors).
Yes - go for it .. two identical packs are fine. I do usually consider having contra-rotating props though to avoid torque effects.
BEC - another (JPF) showed me that standard non-switch BEC's in ESC can be plugged in together and no need to separate power to RX. But Switch-mode BEC's - only one can be used.
LiPO's ... I have twinned them and separated them ... and not seen any significant difference. Theoretically if you parallel them - they should drain together and stay balanced - but in fact they do not. Slight physical differences in the batterys leaves them slightly different after a flight whether parellel'd or not. My Concorde has had both ways and made no difference which.
I'm sure this has been answered or already known ... but basically both +ve leads of batterys should come together and both -ve leads. These then connect to common +ve and -ve leads of both ESC's.
The ESC's then to the their respective motors.
The Rx leads are then put to Y lead to connect to throttle channel of Rx.
You could if you want to be clever - mix the twin motors to rudder - to give differential thrust to help yaw ... but that is an advanced and later item that needs extreme care.
Small schematic attached below ... hope it helps ...