RC Tanks Australia Forum

Hi All
For years I have been going on about using your 9X series/Taranis radio to control the momentum/inertia features for your tank but never really explained how or had those features in any template or model file. My bad - time to fix the situation.

If you have ER9X or ERSKY9X then as you know I would say that you have the best possible firmware for controlling ANYTHING. In this post I'm only going to cover using the Slow Up and Slow Down mix feature. In addition to these features you can also include your throttle response curve and even the use of multipliers all to govern how your tank moves. I'm not going to go into those more advanced features here.

Ok here is how....
First up a basic understanding of how Slow Up and Slow down work - designed originally for planes these functions work exactly as stated - any increase from 75ms up to 225ms is affected by slow up and any decrease affected by slow down. The issue with tanks is that the throttle is neutral at 150us so when we reverse an increase in reverse speed is associated with a DECREASE in the ms value. So reverse acceleration uses your slow down value when we really want it use the slow up value.

Typically we want a high slow up value as tanks do not often go from 0 to 100 in 4 seconds. But if you program in a high slow up value all is good when going forwards. HOWEVER, when you go into reverse and try to stop the tank it just keeps going according to the slow up value. So to get around this we need to setup 3 separate mixes for the throttle channel. One for neutral, one for forwards and one for reverse. Each mix is then activated using the logical switches depending on the position of the THR stick. So create the following 3 mixes on your throttle channel (CH2) (I'm using ersky9x in the example below)

R +100 THR L9 Slow(u2:d2)
R +100 THR L7 Slow(u12:d4)
R +100 THR L8 Slow(u4:d12)

The first mix is for neutral, second for forwards motion and the third for reverse. As the second mix controls forward motion you can adjust the Slow up to dictate how slow the tank speeds up and the slow down to how quick/slow it comes to a stop. I do not like crashing into stuff so I keep this low. The third mix controls reverse movement so counter intuitively it is slow down that controls reverse acceleration.

Now create the three logical switches L7, L8 and L9 to activate the correct mix. So go to L.Switches and create...

L7 v>val THR 4
L8 v<val THR -4
L9 |v|<val THR 5

To explain - L7 actives the forwards mix and comes on when the THR stick is greater than 4 above centre. L8 activates the reverse mix when stick is more than 4 below centre. If stick is between 4 below and 4 above L9 activates the neutral mix. Simples eeek.

For safety it may be good to setup a emergency brake. So go to Safety Switches and add

CH2 S (Choose a physical switch GEA, ELE etc) 0

So when you activate the switch the radio sends out the neutral position.

Ok for your first time it may seem complicated but you need only set up these mixes and switches ONCE and then copy to your other tanks.

The benefit is that you have a great range of control over momentum/inertia values in both forwards and backwards direction, for acceleration and deceleration. A degree of control not offered by ANY tank control unit. However, using your radio makes this degree of control available to ALL tank control units.

Cheers and happy mixing
Kevin G

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rctanksaustralia.com

Used it on my turnigy 9x for a skittish T-34.
Works great
Thanks Kevin