Dodgy Crasher
I'm bulding a Mig 29, not made up my mind single or twin motor vector thrust etc , my questions are if I go twin motor can I put y pieces on and link the motors then use one large esc ? say 60-70amp

If I need to use 2 esc's can I put a y piece on them and put them into the same slot on the receiver.

Or have I got this all wrong and the motors should power up independently, for example I want to go left  so left motor cuts back power and right one increases, looking from the back obviously, I had a plane like this when I was but a beginner, it turned nice and flat and was fun, I liked it so much I gave it to another guy just starting out when I outgrew it instead of just binning or scrapping it.

yeah I know I'm full of daft questions but I discovered that it saves money, time and crashes
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solentlife
1. No you cannot put two Brushless motors on one ESC. Reason is the the ESC senses the pulse as motor turns ... 

2. Yes you can put two ESC via Y lead to one output on Rx ... BUT if the ESC has SBEC - its reccomended to remove one RED lead so only one powers the RX. But if ESC's have linear BEC's - then it does not matter ... both red leads can connect.

OK ... I have a number of models with twin motors ... and I have not removed the one RED lead and all seems OK .... 

If you have enough channels - its worth having the motor / ESC's separate channels - this gives you differential throttle ability to turn as if its rudder ... 
I'll fly anything if I can launch it ! Youtube : solentlifeuk
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jimbosflyin
I'm bulding a Mig 29, not made up my mind single or twin motor vector thrust etc , my questions are if I go twin motor can I put y pieces on and link the motors then use one large esc ? say 60-70amp

If I need to use 2 esc's can I put a y piece on them and put them into the same slot on the receiver.

Or have I got this all wrong and the motors should power up independently, for example I want to go left  so left motor cuts back power and right one increases, looking from the back obviously, I had a plane like this when I was but a beginner, it turned nice and flat and was fun, I liked it so much I gave it to another guy just starting out when I outgrew it instead of just binning or scrapping it.

yeah I know I'm full of daft questions but I discovered that it saves money, time and crashes
Parkflyers International 
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Dodgy Crasher
Hi Jimbo, I take it the 2 esc's go into a splitter then into the single battery mentioned in the diagram.

Hi Solent, I'm liking the sound of differential throttle, now is that the same that was on my little electric trainer years ago, so how does it work, do I have to do some mixing on my DX9 to get that working or need a special receiver to handle that, I basically use dsmx receivers or compatible ones, a mixtures of Lemons and Spektrums in my planes. 
The diagram Jimbo posted is simple enough and needs no further explanation but I do need more info on the differential throttle before I make up my mind, twin motor or kickass single motor, there is some really high spinning motors out there for heli's and cars and adapting them to a plane would be simple, I just put one in a plane and tried it 2 days ago and it leaves my hand like and airgun pellet when on full throttle, my mate reckons it's quicker than my Durafly xtraracer, that would put it in the 100mph category, not bad for a home made foamie ðŸ˜œðŸ‘
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JTiger


This is a good video for setting up differential thrust on a Spektrum radio. He's using a DX6 but that should be almost the same as DX9. 
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Dodgy Crasher
Ha thankyou JTiger ðŸ˜ðŸ‘ ðŸ™Œ ðŸ™ŒðŸ™Œ
Thats perfect, same set up as a DX9 so easy for me to follow, I have saved this youtube video on my bookmarks, I was especially interested in the part where he said tying 6 motors together with 3 each side, pity the guy did not go into that a bit deeper, it would have been interesting to see how he worked that on just 2 esc's, I have not started the build on the Highlander yet but twin wing mounted motors looks an easy option, run the wires in the wings bere putting the skin on. Hmm I feel a complicated/challenging build stirring in the back of my mind.
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solentlife
My Lancaster has 4 engines ... 4 ESC's .... from 2 separate channels on my RX. It has a single battery.

Its simple ... battery connects to a Y main lead - the ESC's then are in pairs connected to one each of the battery Y lead connectors. The ESC's are connected i those pairs to one each of Rx channel.

A further refinement I have is to not have -ve differential (that's a line in programming to sort that) ... it means that on finals when I give rudder command - one engine speeds up but other does not reduce .. so I stay flying !! 

4 motors 4 esc.jpg 
I'll fly anything if I can launch it ! Youtube : solentlifeuk
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Dodgy Crasher
Hi Solent, so you put positive differential into both sides instead of one negative and one positive as shown in the youtube clip, that was probably the set up in my little trainer as I don't recall it totally cutting power to one side, I more seem to remember it reducing slightly while the other side powered up more, thereby making flat turns with little or no elevator required, which was probably more mixing on the transmitter via rudder and adding some up elevator.
I think I'm grasping this now, and the Highlander model plans from this site with 2 small wing mounted motors is looking ever more likely, it will also let me shave a small amount of weight from the nose and if the 2 motors fall closer to the cog then it's game on for a 2200a 3s lipo to power it all.
Thankyou again Solent your input is great as are the other guys who have responded to this thread.
I will post a photo once I get around to making that plane, hopefully before the summer.
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solentlife
mmmm hard to explain for you as I don't use Spektrum.

Basically I have programming line in each motor channel which takes rudder instruction to say + or - to respective motor. The +ve is about 20% but -ve is zero%.

This then means that one motor speeds up to yaw forward ... while other motor stays at throttle set speed and is less than other motor. Push rudder stick other way and now the other motor gets the +ve while other gets the zero -ve.

I started doing that because when on landing finals - last thing you want is one motor to drop below flight setting. 

But if your model is a floater or you land at decent speed .. its actually not such a problem.
I'll fly anything if I can launch it ! Youtube : solentlifeuk
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Dodgy Crasher
Hi Solent,
I see where you are going regards to the final tweaking if landing in not ideal windy conditions, motor cuts on one side equals bad news .
However I did see on the youtube clip the guy sets it all on an on/off switch so he can fly normal, now that could be a plane saver if things are not going well and that is one thing I will definately go with.
That guy also set 100% positive and negative and I'm guessing that can be seriously reduced to 30% or whatever so one motor drops by that amount and the other increases by the same, instead of the all or nothing set up he has.
I'm going to set that up on the bench as soon as we get some weather good enough to make me want to stay in my garage for more than 2 minutes.
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solentlife
100% each way is definitely not something I would ever do. But in a video - it shows the effect better.

The max I would ever consider would be about 40% but it depends on the model. My HK Lancaster has about 20% I think ... the FRC Mossie I crashed !! had about 25% I think ... 

Its more for ground handling ... and 'rudder' effect ... so it does not need lots of differential.
I'll fly anything if I can launch it ! Youtube : solentlifeuk
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solentlife
I use er9x / ersky9x in my radios and the differential is :

Ch 3 :  100 THR
+         30 RUD      x>0

Ch 6 :   100 THR
+          -30 RUD    x<0

Basically this says full throttle range on Ch 3 & 6. Add 30% Rudder but the 0 means send 0 rudder command that reduces throttle

The + /- and < .. > are of course because of the contra rotating motors I have !!  If they all turned same way - then there would be no need for + / - on the 30% or < .. > .. 
I'll fly anything if I can launch it ! Youtube : solentlifeuk
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solentlife
You could of course add a rudder 'curve' on each throttle channel to initiate the differential .... 
I'll fly anything if I can launch it ! Youtube : solentlifeuk
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Dodgy Crasher
Hi Solent,
I see your also giving this some thought on my behalf, much appreciated ðŸ‘
Now I think contra rotating motors is the only way to go to avoid torque to one side, i tried NOT contra rotating a while back when I couldn't wait on a spare prop arriving by donkey class post from HobbyKing and had to trim the rudder heavy one way to fly straight.
So rudder curve are you talking about an expo curve ? 
I went to set up 2 motors on a piece of wood today and only stopped when I realised I did not have two matching esc's, I have 2 x turnigy 1400kv motors but then noticed I had a 20a and 30 a esc, and I have no idea if this would have an impact so I might need to wait until I get a matching pair.
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XDmToter
I went to set up 2 motors on a piece of wood today and only stopped when I realised I did not have two matching esc's, I have 2 x turnigy 1400kv motors but then noticed I had a 20a and 30 a esc, and I have no idea if this would have an impact so I might need to wait until I get a matching pair.


If you are just bench testing to get your radio mixes right, I wouldn't worry about having two different ESCs. However, I would definitely use matching ESCs in the plane. You don't want a more efficient ESC generating more thrust on one side. 
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