BTW, it you have to power a lot of servos, one of these may help: https://www.servocity.com/servos/ser...g/power-boards
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Do I need a BEC?
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You need to search for the Voltage limits of the servos. Some are rated 6V (five NiCd cells), so can go up to about 7.5V, the full charge of a NiCd pack, and others say 4.8V, so maximum 6V. Newer servos can be powered directly by 2S LiPos.
I generally use 5.5V, just to make the servos a little more responsive, at the expense of a bit more current to the analog servos.
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Expert opinions please :)I'm working on a plane , and this is my first where i'm going to have a seperate BEC.
I have all my parts now for my Hanger 9 Spitfire. Ready to do my soldering/wiring of my ESC and BEC. And start assembly of this Spitfire
Question on wiring. Should i NOT deviate from the provided wiring diagram? OR....as in the pictures i took, wire my ESC & BEC in the way i've laid it out in the pics? Pic 2 & 3 are the same configuration. As you can see, going 12s.
Thanks,
Lon
Lon
EFlite F-16 80mm, EFite DRACO, EFlite Night Radian, E-Flite P51 1.5m
Freewing A-10 80mm, F-86 80mm, F-15 90mm, Avanti. FMS DHC-2 Beaver, Fliteline P-38L ,HSD HME-262, HSD F86.
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Originally posted by Lon View PostExpert opinions please :)I'm working on a plane , and this is my first where i'm going to have a seperate BEC.
I have all my parts now for my Hanger 9 Spitfire. Ready to do my soldering/wiring of my ESC and BEC. And start assembly of this Spitfire
Question on wiring. Should i NOT deviate from the provided wiring diagram? OR....as in the pictures i took, wire my ESC & BEC in the way i've laid it out in the pics? Pic 2 & 3 are the same configuration. As you can see, going 12s.
Thanks,
Lon
In the drawing the BEC is only getting fed by one (1S-6S) battery.Warbird Charlie
HSD Skyraider FlightLine OV-10 FMS 1400: P-40B, P-51, F4U, F6F, T-28, P-40E, Pitts, 1700 F4U & F7F, FOX glider Freewing A-6, T-33, P-51 Dynam ME-262, Waco TF Giant P-47; ESM F7F-3 LX PBJ-1 EFL CZ T-28, C-150, 1500 P-51 & FW-190
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Originally posted by OV10 View Post
Lon........Don't deviate from the drawing. The way you have it laid out on the table is a serial setup for 12S which is fine so far until you jam that down a 6S BEC.
In the drawing the BEC is only getting fed by one (1S-6S) battery.Lon
EFlite F-16 80mm, EFite DRACO, EFlite Night Radian, E-Flite P51 1.5m
Freewing A-10 80mm, F-86 80mm, F-15 90mm, Avanti. FMS DHC-2 Beaver, Fliteline P-38L ,HSD HME-262, HSD F86.
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Originally posted by Lon View PostExpert opinions please :)I'm working on a plane , and this is my first where i'm going to have a seperate BEC.
I have all my parts now for my Hanger 9 Spitfire. Ready to do my soldering/wiring of my ESC and BEC. And start assembly of this Spitfire
Question on wiring. Should i NOT deviate from the provided wiring diagram? OR....as in the pictures i took, wire my ESC & BEC in the way i've laid it out in the pics? Pic 2 & 3 are the same configuration. As you can see, going 12s.
Thanks,
Lon
Also, they emphasize this in the instructions, but make sure 0v is the same in your BEC and your ESC - 0v side of the BEC MUST be the black wire going into the ESC. If you connect your BEC across the other battery, effectively 25v-50v, then it will start to operate as normal, because it still sees 25v across it. But its ground goes to the receiver. This also has a ground from the ESC, which is connected to the black wire of the battery. So now you just shorted the two terminals of the low-side battery though your ESC and receiver. Kaboom! Most likely the receiver blows up first, but it can damage both. I have seen this done before, and fortunately the receiver became a flaming open-circuit quickly enough that the ESC survived.
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Originally posted by fhhuber View Poston my 12S aircraft I use a separate 2 cell LiFe
(actually 2X 2S LiFe and a Spektrum PowerSafe RX)
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Originally posted by Gringotuerto View Post
Me too, exactly the same. It is a bit of extra work to take these in and out and charge them, but I'm sure they can supply much more current than any BEC. And the redundancy is good. And I don't need to charge them every flight, just once for the day. Also you have to make sure all elements in your system can withstand 7.2v peak, whereas a BEC can be set for whatever output voltage you want.
A local club member was trying to make an airplane work with a mix of 4.8v, 6.0V and 7.4v nominal servos. The 4.8 v servos could not withstand more than 6.0v. The 7.4 v nominal (rated for 2S LiPo direct) servos would not operate properly below 6.0v. he was supplying the system with 5.0v regulated. The result was constant issues with ALL of the servos, preventing it from ever passing a pre-flight control system test.
He sold me the aircraft, before I discovered the cause of the problems. Its getting ALL 6.0v nominal rated ( rated to handle 7.4 v maximum) digital servos installed. Even the 9 gram servo for the choke. (strange location for the choke servo required the small servo)FF gliders and rubber power since 1966, CL 1970-1990, RC since 1975.
current planes from 1/2 oz to 22 lbs
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