Mixing Question, Spektrum, motors not starting simultaneously.

[Thembi]

I'm building the King Tiger by Lubos (which is amazing!).

I'm using my Spektrum DX6e to run it (I know there are all types of boards, transmitters, etc. for tanks but this is what I have)

I have two ESCs running into the elevator and ailerons on the receiver and have the mixing figured out and does what I want it to do, but....
...the motors don't always begin running at the same time, there is some lag in one or the other when starting to move forward/backward or turn. I played with the trim buttons near the gimbals on the transmitter and it is better.

Is this the best way? I see there is a trim option in the mixing but haven't played with it yet, should I use that as well? THANK YOU!!

[General Jumbo01]

I di this sort of thing with twin prop, twin motor boats. Set both ESCs to work from one signal and then each ESC to increase / decrease as a mix from input 2. You can select say the left dongle to provide forward/reverse throttle (back forth) and steering left right by the mix. It makes for a simple, natural solution in use. You can turn on the spot by using the mix to reduce the esc throttle to go into reverse on extreme left or right 'turn'.
.

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[Pavel]

There is another nasty problem...
Motors and speed controllers are not made as twins.
I had this problem even without mixing.
I have 4 motors and 4 speed controllers.
And as in your scenario, the motors did not start working at the same time, I swapped all the devices, but the result was the same...
I always have several motors and controllers in stock, I found some that worked more or less at the same time.
Yes, you understand that all the motors are on one gas channel...

[General Jumbo01]

You show a set of 35t cans so plenty of torque but low revs. One not so simple solution would be to swap it all out for sensored brushless motors and programmable brushless ESCs where you can carefully tune each motor start just when you want them too. You could also check that all props are able to rotate freely with no snagging. Failing all that, just blast off the start on full throttle!

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[jhamm]

Hi Thembi,
all brush motors are set to clockwise rotation in the timing by default.
If you run the motor anticlockwise, it runs slower.
The timing can be adjusted on the 540 13T motors seen on your picture.
This allows you to achieve the same speeds
Look at the video:
https://www.youtube.com/watch?v=UMN8a4N839Q

[General Jumbo01]

Hi again Thembi, l failed to spot you are running 13.5 motors. These are higher revving motors made for race cars so are less 'stable' than a 27t or more stock motor. You may find that simple replacing them with a well known brand 27t can, a low cost fix, may do the job.

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[Pavel]

You have not disconnected the red wire from the One speed controller!
There must be ONE BEC
One of the reasons for incorrect operation!!!

[Thembi]

You have not disconnected the red wire from the One speed controller!
There must be ONE BEC
One of the reasons for incorrect operation!!!

You mean a positive lead to its battery? Really?....why?

Sorry, what is "BEC"

Thanks!

[Thembi]

There is another nasty problem...
Motors and speed controllers are not made as twins.
I had this problem even without mixing.
I have 4 motors and 4 speed controllers.
And as in your scenario, the motors did not start working at the same time, I swapped all the devices, but the result was the same...
I always have several motors and controllers in stock, I found some that worked more or less at the same time.
Yes, you understand that all the motors are on one gas channel...

Thanks, I think I heard about this before we guys running two motors on r/c planes.

[Thembi]

You show a set of 35t cans so plenty of torque but low revs. One not so simple solution would be to swap it all out for sensored brushless motors and programmable brushless ESCs where you can carefully tune each motor start just when you want them too. You could also check that all props are able to rotate freely with no snagging. Failing all that, just blast off the start on full throttle!

Sent from my SM-A226B using Tapatalk

These are what the designer (https://www.3dprintedtanks.com/english/) recommended, they seem to run at a decent speed