Help on Mixing a Turnigy 9XR Pro

[DeepDiver]

Hi One & All
I am hopping that you can help me out here, I have just got myself a twin engine model boat, and would like to mix the motors, so that as I make a turn the inner motor slows down and the outer motor speeds up. yes I could just go out and buy a mixer but were is the fun in that, the radio is a Turnigy 9XR Pro
I am 75 years old so If you have any idea how I may be able to do this please take this in to account, in other words could you please take it step by step.
Thanking you for any help you can give.
Fred

[MikeB]

Assumptions:
Rudder is on channel 1
One motor throttle is on channel 2
The other motor throttle is on channel 3
You have erskyTx firmware on the 9XR-PRO

Mixes:
CH1 +100%Rud
CH2 +100%Thr
CH2 + 20%Rud
CH3 +100%Thr
CH3 -20%Rud

For help editing the mixes, the information in this manual: viewtopic.php?t=6473 is the same for erskyTx.

Mike

[DeepDiver]

Hi Mike
Thank you for your reply.
On my transmitter I have the rudder on Ch 2 and the Throttle on Ch4, now if I have this correct I go to page 5 (Mixer)
Go to CH2 and open
Source to Rudder
Weight to 100
Back to page 5
go to CH4 and open
Source to Throttle
Weight 100
back to page 5
Have I got this right so far?
How do I set the Throttle to 20% and the rudder to 20%
Thank you for your help Mike also Sorry to be a pain in the butt,
Fred

[MikeB]

To be able to control the motors at different speeds, you must use two channels for the throttle, one controlling each motor. You will clearly need two speed controllers, one for each motor.
Do you have this?

Mike

[DeepDiver]

Hi Mike
Thank you for your replay, and for the help you are giving.
Yes I have two ESC, do I read this right, two ESC going into two channels, say Ch 1 & Ch 4 this would then give me up & down on the two sticks, making it tank steering, is that right, I have also removed one of the red wires form one of the ESC.
Fred

[ReSt]

This is my programming for a 2 motor ship with motor support for steering.


What does it do?

First of all, the more you push a VERTICAL stick away from the neutral/minimum point, the greater the effect of its HORIZONTAL movement.
And my transmitter has the throttle stick on the right side.


All switches down = away from you.
Motors are disabled.

Throttle cut switch up
Motors enabled

Left vertical (Lv) stick neutral ==> both motors stop
Lv stick forward ==> both motors with same speed forward
Lv stick backward ==> both motors with same speed backward

+ Rudder switch On
motors are additionally controlled by left horizontal (Lh) stick (added to Lv)
The curve inner motor can be reduced from 100% down to 0
Lh left ==> left motor speed reduced between 100% to 0
Lh right ==> right motor speed reduced between 100% to 0


+ Ail/DRate switch On
similar to Rudder switch but motorspeed varied between 100% to -100%
Motors are additionally controlled by right horizontal (Rh) stick (added to Lv and Lh)
Steering support due to motor speed control and Rudder work in the same direction.
With both horizontal sticks pointing to the same side, the curve inner motor can even be reversed up to -100%


+ Gear switch on
reverses the direction of the rudder.
Rudder steers opposit to the direction of the motors, hopefully allowing some kind of shifting sideward.

Idea behind, but I don't know if it really works:
Both sticks pushed left and away will run the left motor pull with 100% and the right motor push with 100% and the rudder steering a left curve.
Both motors running with the same speed, but one motor pushes forward and the other pulls backward, there will be not much movement forward or backward
This should result in a slow left turn and the nose of the ship should try to turn left.
Now when (with Gear switch on) the Rudder is turned steering right (opposit to the motorcurve) in the water stream of the pushing motor, it should try to shift the backend of the ship to the left. And when back and nose try to go left, the ship could move sideward to the left ???



Setup:
======
Rudder is on channel 3.
The brushed motors are running inverse, the left motor has a left turning propeller and the right Propeller is a right turning one.
The left motor is attached to channel 1 and the right motor to channel 2.
Every motor has an ESC that can reverse the motor direction, that is with the stick in middle position, the motors stop.
As the neutral position for the motors is in the middle position of the stick, I use the self neutralizing stick (not the normal throttle stick) to control the motor speed and direction (upper half is forward and lower half is backward).
As this neutral position is really close, I enlarge it by using curve9 to enlarge the neutral area of the stick.

There are only settings in the Mixers, the Limits and the Curves


The programming:
================
Ch10 ==> Ch15 ==> Ch1 ==> left motor
Ch12 ==> Ch16 ==> Ch2 ==> right motor
Ch3 ==> Rudder

The mixing is done on ch10/12 using several multiply mixes
On ch15/16 a delay is added
on ch1/2 this delayed mix gets a wider neutral range and finally goes to the ESCs

Why use delays?
When rapidly changing the motorspeed from fully forward to fully backward or vice versa, there is a high current when the motor has to reverse the direction and my Escs may break the current for the reverse direction and simply stop the motor, nomore supplying current for the reversed direction (timeout forever). I then must restart the motor in the previous direction, go back to neutral, wait a moment and then continue with the reversed direction to reactivate the motor. By means of the delay, the reaction of the signal is slowed down so far, that my ESCs don't break the connection.

Switched mixes and delay in the same mix often do not work really good, therefor the separation of the mixes(ch10/12) with the delays (ch15/16)

With the output from ch15/16 we have the necessary signal, but still with the critical small neutral point.
That is resolved with Ch1/2 where by means of curve9 the neutral point is widened to a neutral area. (use of curve 17/18 allows even better adaption)



Rename the 2Motorship.bin.hex to 2Motorship.bin and load it into EEpSky to simulate the programming
And... by the way, I'm 80

2MotorShip.pdf

(68.71 KiB) Downloaded 41 times

2Motorship.bin.hex

(512 KiB) Downloaded 33 times

[MikeB]

With the mixer entries you are able to map any source (e.g. stick) to any output. So if you have the two speed controllers on channels 1 and 4,
start with three mixes:
CH1 +100%Thr
CH2 +100%Rud
CH4 +100%Thr
so the throttle stick will operate both motors and the rudder stick operate the rudder.

Now just add two more entries to add the rudder mixes in. Have the CH1 mix highlighted and press MENU, you should get a popup menu. Go down to "INSERT" and press MENU and a new mix will be created. Edit it to give the +20%Rud entry (weight = 20%). Repeat the insert on channel 4 to give the -20%Rud entry (weight = -20%):

CH1 +100%Thr
CH1 + 20%Rud
CH2 +100%Rud
CH4 +100%Thr
CH4 -20%Rud

Mike

[DeepDiver]

ReST & Mike
Thank you gentlemen for your time and help, it looks as if I now have some reading to do, after a quick read these are my thoughts.
Mick I may be wrong and I do hope I am, it looks as if I will have tank steering?
ReST that is a lot of programming, at the moment I am having trouble getting my head around as to were are CH 10 - 12 -15 & 16, I hope in time it will all become clear.
Talk to you again soon.
Fred

[ReSt]

The total mixup is done in steps.
ch10/12, ch15/16 and ch1/2 are the same programming but for left/right motor.
In the first step (ch10/12) the inputs from the sticks are mixed, in the second step (ch15/16) the delay is added and in the last step(ch1/2) the zero point of the 'throttle' channels is widend via curve9 to have a wider range for the stick, where the motors ar stopped.
This is done in separate steps because it is easier to understand and it does work more reliable.

Reinhard