4 in 1 ESC.

[ERIC CLAPHAM]

I am toying with the idea of building one of two electric 4-engined models I have been collecting data on. They are both fairly small and to save weight, I thought I would have to use 4 small brushed motors thru one ESC. Is it possible to use brushless units with a 4 in 1 ESC for normal throttle control so reducing the AUW even more ?

[Denis Watkins]

There are brushed motor ESCs Eric, with normal 2 wire feeds and you need then do the arithmatic to fit in with your need.

[ERIC CLAPHAM]

I am well aware that there are ESCs for brushed motors having even built and used quite a few over the years. My question was - Can I use 4 brushless motors thru one 4 in 1 ESC for normal throttle control. That is, rather than using 4 dedicated ESCs.

[Colin Bernard]

I have one fitted in my Vulcan with 4 EDFs. Hasn't flown yet, but testing shows that the 4 in 1 unit works well.

[Denis Watkins]

Wow Eric, I thought you were just going to try a brushless ESC. Apologies

The ESC will treat the 4 motors as one output, but as with all things electrical, the least path of resistance,

One motor may set off before the others, but experiment and balance them up

[Allan Bennett]

I tried a 4-in-1 ESC on one of my quads. It certainly worked okay, but I ditched it after the module controlling one of the motors blew, and because I didn't like the plug-in nature of all the modules inside it. I replaced it with 4 individual ESCs which, I think, are lighter than the particular 4-in-1 I had (it was inside an aluminium box which acted as a heat-sink). Individual ESCs, in my situation, actually made placement easier too because the 4-in-1 was particularly chunky.

By far the simplest arrangement is a single brushed ESC driving four brushed motors, but the disadvantage is brushed motors are generally less efficient than brushless ones (so heavier for the same power output), and will need more maintenance. If going this route, the ESC needs to be rated for at least the total of the four motors' amps consumption.

[Stephen Jones]

That is interesting comment Allen,

I also was toying with the idea of a 4 in 1 Esc or a 2 in 1 ESC for some projects i would like to get on the way .

But when having problems with a twin that is using two separate Esc that would not fire up correctly or one would cut out . The Project was put on hold.

So are you saying that you need to make sure that each ESC is rated at being able to power all the motors even though it will only be powering one of them and this is to compensate for the total load .

If the expected load of each motor is 20 amps then i would need two 50 amp ESC for a twin ?

is this right ?

Steve .

[Simon Chaddock]

Stephen

I have 4 twins and one 4 engine plane all with separate ESCs with no problem.

Yes the motors may start to turn at very slightly different throttle points but must run under load at pretty similar speeds as you can hear the distinctive frequency 'beat' of nearly matched RPM.

[Frank Skilbeck]

Posted by Stephen Jones on 23/09/2017 11:42:33:

If the expected load of each motor is 20 amps then i would need two 50 amp ESC for a twin ?

is this right ?

Steve .

No, if your motor/prop combination pulls 20 amps then you need an ESC on each motor that will comfortably supply 20amps, 30 amp ESCs would do the job. But if using a single supply battery then you will need one that can supply 40 amps.

On a couple of twins I've got I've plugged the ESCs into separate channels in the Rx and set it up so I can have rudder mixed in, makes handling a tail dragger on the ground easier and works really well on a twin engine float plane.

[Stephen Jones]

Thank`s Frank,

So i need a 40 amp Esc for each motor on a twin that is pulling 20 amps on each motor and are fed from one supply battery, Say a 1800 3s 40c lipo .

Steve.

[Allan Bennett]

Posted by Stephen Jones on 23/09/2017 11:42:33:

. . . So are you saying that you need to make sure that each ESC is rated at being able to power all the motors even though it will only be powering one of them and this is to compensate for the total load .

If the expected load of each motor is 20 amps then i would need two 50 amp ESC for a twin ?

is this right ?

Steve .

No, my comment refers to a brushed motor, where they can all be controlled by a single ESC. So four 20A brushed motors could be controlled by a single 80A brushed ESC. They could also be controlled in two pairs by two 40A brushed ESCs, if that would make the wiring simpler.

I have several electric twins and, with brushless motors, have never had any out-of-sync problem. The key in my opinion is to use good quality motors and ESCs so you can be sure their characteristics are as near the same as is possible. Then you have to "teach" each ESC your transmitter's high and low stick positions; usually this is done by powering up the trannie, putting its throttle stick to maximum, and then powering up the receiver and ESC. The ESC should then beep a few times, at which point you move the throttle stick to zero, and should hear more beeps. That should indicate that the ESC has learned what the transmitter's full throttle range is. Do this calibration without any prop installed, in case a fault causes the motor to start unexpectedly.

When using brushed motors it's quite easy for them to get out of sync if their brushes wear at different rates. I crashed one model when the brushes on one motor failed completely on take-off That's when I converted it to brushless.

[john davidson 1]

Brushless multis must use an esc for each motor and cut/disconnect the red wire on all except one esc to supply juice to the receiver. Just built and flown a B17 , works perfect, a good tip best to buy motors and esc's as a batch to ensure they are matched . I would be interested to receive info on how to use a quad copter esc in a multi plane.

[Paul Marsh]

I have and had no problems. Still fly this, now on 2.4 and using twice more capacity batteries and 3 s. Seems to cope ok, only need 1/2 power for cruise, where on the heavy 8 cell Nicad, it was full chat, struggle for 6 mins than land.

Was using 3000 mah Nicd 8 cell.

Now using 6000 mah 3 s lipo and still is lighter than the original pack - tail heavy now, so ideally it can go up to 8000mah and be the same weight. Used then 2 x 4000 mah 3 s packs in parallel. and stays up for over 20 mins...