Thread Tools
Jan 15, 2020, 09:53 PM
Registered User
Thread OP
Discussion

wiring multiple electric brushless motors for a four motor aircraft


I would like schematics and or explanations for wiring four identical brushless motors, with four identical esc 's. I'm also curious about the differences in hooking up, if any ,when using a 3S1P 2200 mAH 11.1V battery as opposed to a 4S 4000 mAH 14.8V. Then there is the question of the need for a BEC when in my case using six servos: 2 Hitec HS-65mg servos with 4 Free wing 17G digital servos for a total of 6.. should a BEC be incorporated? And the the question of using a Seperate power source for the receiver. For facts I'm wiring four Leopard 2835-8T 1038kv motors and four Mantis 35 AMP controllers. This will be hooked into a SPEKTRUM 6-8 channel reciever. Thank You all it would be greatly appreciated. Again TKS
Sign up now
to remove ads between posts
Jan 15, 2020, 11:36 PM
Registered User
Wintr's Avatar
Quote:
Originally Posted by fastruchard
I would like schematics and or explanations for wiring four identical brushless motors, with four identical esc 's.
Assuming a single battery, you would need to connect all four red ESC wires together, then to the + terminal of the battery connector; same for the black wires. That way, all four ESCs are connected to the same battery at the same time.
Quote:
I'm also curious about the differences in hooking up, if any ,when using a 3S1P 2200 mAH 11.1V battery as opposed to a 4S 4000 mAH 14.8V.
The 4S battery will make the motors run about 1/3 faster. You may need to use smaller size props, so as not to burn up the ESCs from excess current, or the motors from excess power. To really answer this question you need a Watt meter, so you can measure the actual current and power with each battery (only need one motor hooked up for this).
Quote:
Then there is the question of the need for a BEC when in my case using six servos: 2 Hitec HS-65mg servos with 4 Free wing 17G digital servos for a total of 6.. should a BEC be incorporated? And the the question of using a Seperate power source for the receiver. For facts I'm wiring four Leopard 2835-8T 1038kv motors and four Mantis 35 AMP controllers. This will be hooked into a SPEKTRUM 6-8 channel reciever. Thank You all it would be greatly appreciated. Again TKS
The ESCs probably come with an internal BEC. You need read the specs to determine if they are switching type (SBEC or UBEC) instead of the old type linear BEC, and how much current (Amps) one can provide. The old linear BECs could provide less current than the nominal rating when using a higher Voltage battery. Then, look for something that indicates if the BECs may be connected in safely in parallel; if the specs don't mention this, consult the maker or assume no. If no, then you will have to extract the red wire from three, and tape it back, so they don't 'fight' each other. If the current of one isn't high enough, and you can't run them in parallel, you may need a higher current external BEC; I'd guess 5A should be enough, but a lot depends on how fast the model will fly. The receiver gets its power from the BEC, and provides that power to the servos.
Jan 16, 2020, 02:31 AM
If it flies, I can crash it.
rocketsled666's Avatar
What Wintr said is 100% correct.

I do think you have a lot of servos for one BEC. But you could use the BECs from your ESCs to power separate groups of servos.

Plug one ESC in to the RX as normal (assuming you're using a 4x harness to drive all 4 ESCs from one channel, but it doesn't matter where the ESC plugs in, just plug it in. Don't cut any wires).

For the other three ESCs, cut the red wire as Wintr instructs. But...

Pick a few servos to power separately from the rest and cut their red wires going to the RX. The end of the red wire that goes to the servo should then be connected to the end of the red wire that goes to one of the ESCs (that you previously cut per Wintr's instructions).

Now, you have enough power for all your servos even if one BEC doesn't have enough power for all your servos.
Jan 16, 2020, 03:11 AM
B for Bruce
BMatthews's Avatar
Usually the advice for the BEC positives is to clip all but one and run the Rx and servos off just one BEC so they don't fight each other. This might mean you want to get ONE that has a 5A output if you're running a lot of servos on a bigger and heavier model where the load on the servos will be a little higher.

Or clip all the ESC red leads and run the Rx and servos off a dedicated regulator that can easily handle the power.
Jan 16, 2020, 04:43 AM
Registered User
Thread OP
Thank You Gentleman, very helpful
Jan 16, 2020, 06:35 AM
An itch?. Scratch build.
eflightray's Avatar
Personally I like to have the ESCs connected so that they can be set-up individually, the - set throttle range - in the ESC instructions.
It also allows an ESC to be replaced easily should the magic smoke escape.

Probably not really necessary, just my way of doing things.

Addition

Extending the leads between the ESC and motor is safer than extending the battery to ESC leads, (which is not recommended. there is a thread on the subject).

.
Last edited by eflightray; Jan 16, 2020 at 06:38 AM. Reason: Addition
Jan 16, 2020, 08:35 AM
homo ludens modellisticus
Ron van Sommeren's Avatar
Don't forget to remove the red pin from one of your ESC connectors. Otherwise you get two different voltages, linear lbec and battery, or lbec and lbec, fighting each other. Or in the case of switching sbecs, two frequencies fighting each other.
No need to remove the red pin if you have a bec-less controller.

(UBEC is a propriatery brand name, a generic informationless acronym, I prefer LBEC, linear, and SBEC, switching, those two acronyms contain more info.)

But don´t cut the red wire, you may need it again in another plane.





Last edited by Ron van Sommeren; Jan 22, 2020 at 11:55 AM.
Jan 16, 2020, 08:38 AM
homo ludens modellisticus
Ron van Sommeren's Avatar
Quote:
Originally Posted by eflightray
Extending the leads between the ESC and motor is safer than extending the battery to ESC leads, (which is not recommended. there is a thread on the subject). ....
Too long wires batteryside will kill ESC over time: precautions, solutions & workarounds - RCG
Contents
  • Two problems
    ◦ Voltage spikes higher than battery voltage: transistor/FET/chip breakdown.
    ◦ Current through input capacitors too high: overheating/popping/exploding.
  • Example four costly controllers consecutively cremated
  • Solution I: simply lengthen the motor wires instead
  • Solution II: add extra capacitors, rules of thumb
    Calculation spreadsheet
  • Capacitor type and polarity/orientation!
  • How & where (not) to add extra capacitors
    As close to or on controller.
  • DIY capacitor pack pictures
  • Capacitor & pack suppliers
  • Expert/manufacturer opinions & their rules of thumb
    They all say the same ... noise_reduction_101, switching_power_supply_design_101.
  • Cause, explanation, water hammer/knock analogy&video, theory
    References
  • Measurements & scope traces

Vriendelijke groeten Ron
• Without a watt-meter you are in the dark ... until something starts to glow •
e-flight calculatorswatt-metersdiy motor tips&tricksCumulus MFC
Jan 16, 2020, 08:45 AM
CR5
CR5
Registered User
If you want to use your 3S 2200mAh pack make sure it is capable of putting out enough Amps to support 4 motors. If each motor has a 30A ESC and the motor/prop combination allows it to pull close to the ESC's rated current you need to multiply it by 4 (120A) and ensure your battery can support that (2.2xC rating).

Everything else you need to consider has been covered in previous posts.

Don't let the magic smoke out
Jan 16, 2020, 08:56 AM
homo ludens modellisticus
Ron van Sommeren's Avatar
Quote:
Originally Posted by fastruchard
... when using a 3S1P 2200 mAh 11.1V battery as opposed to a 4S 4000 mAh 14.8V.
RPM is proportional to voltage, wants to increase by factor (4/3) = 1.3, 30% higher.
Current drawn is proportional to voltage squared current wants to increase by factor (4/3)² = 1.7, 70% more.
Power drawn is proportional to voltage cubed power wants to increase by factor (4/3)³ = 2.3, 130% more.

You probably have to prop down to get current within limits.

Small changes in power system setup can have huge effects.
Increase in current with one or two cells added, simple table.

Vriendelijke groeten Ron
• Without a watt-meter you are in the dark ... until something starts to glow •
e-flight calculatorswatt-metersdiy motor tips&tricksCumulus MFC
Last edited by Ron van Sommeren; Jan 16, 2020 at 09:02 AM.
Jan 16, 2020, 02:29 PM
Registered User
Thread OP
Quote:
Originally Posted by Ron van Sommeren
Don't forget to remove the red pin from your ESC connector. Otherwise you get two different voltages, linear lbec and battery, or lbec and lbec, fighting each other. Or in the case of switching sbecs, two frequencies.
No need to remove the red pin if have a bec-less controller.

(UBEC is a propriatery brand name, a generic informationless acronym, I prefer LBEC, linear, and SBEC, switching, those two acronyms contain more info.)

But don´t cut the red wire, you may need it again in another plane.





Thank You, for the likes of me a picture is worth a thousand words though I have used this procedure for reversing motor running direction THANKS
Jan 16, 2020, 02:38 PM
Registered User
Thread OP
You guys are the Greatest, I'm learning more every day here on r/c builders.
Jan 16, 2020, 04:20 PM
Registered User

Or you could use one of these external BEC's to simplify things


Quote:
Originally Posted by fastruchard
You guys are the Greatest, I'm learning more every day here on r/c builders.
Or you could use one of these external BEC's to simplify things, I use them on anything above 3S for piece of mind. They're better quality than the internal BEC on many ESC's.

http://www.castlecreations.com/en/cc...ro-010-0004-01

http://www.castlecreations.com/en/cc-bec-010-0004-00
Jan 16, 2020, 10:01 PM
If it flies, I can crash it.
rocketsled666's Avatar
In this model there are four ESCs, each with its own BEC. Buying another BEC is a needless expense. The BEC functionality of the ESC is independent of the ESC functionality. All you have to do is tie all the grounds together, and then separately feed power to whatever you want from whichever of the ESC BECs you want. There is literally no reason to add another BEC. Electrically, it's equivalent to using one of the ESCs BEC. There is literally no downside to powering devices in the same model with separate power sources.
Jan 28, 2020, 09:31 PM
Registered User
Thread OP

Going confused


Please see attached picture need to know what goes where with this ESC there is no color code. How am I to know what plugs where.


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Need help with wiring for charging multiple 1S batteries Asalas77 Batteries and Chargers 12 Jan 21, 2019 06:58 AM
Discussion Wiring electric motor Trisnpod Electric Plane Talk 10 Oct 23, 2015 07:16 PM
Help! question on wiring for four motor setup Don McGill Power Systems 1 Jan 05, 2008 04:41 PM
Two Or Four Brushless Motors On A Plane Do Need Two Or Four Brushless Esc's agapornis Power Systems 1 Jul 17, 2005 06:17 PM