Tank Telemetry

[nikolas george]

Hi All,

I have been playing with telemetry on my Elephant using a Taranis Radio System.
I am not an expert at 'tronics, but so far i have found that ........
- when i switch the tank on but do'nt activate anything the current is 0.3 amps
- when I drive in straight lines in the hallway (tile floor) the current is up to 6 amps depending on the speed I go at. Turning is less, but I have to go very slow for that.
- in the garden in a straight line it is about 7 amps
- turning on short grass varies but is probably 12 amps-15 amps. I have not tried to spin the tank on the grass because I do'nt want to pull it up.
- sound on its own is about 2 amps
- smoke on its own (without moving) is also 2 amps
- Gun up/down (servo) is a bit hard to read, but I would say 1- 2 amps and the same with side to side (maybe a little less)

As I said I am not an expert - so I want to check if this sounds about right or if I have wired something wrong. I am using a Taranis current sensor and it is placed just after the battery but my neighbour said this was the wrong place (?) but then did not know where it should go. My simple brain says that voltage and current should be recorded as close to the battery as possible.

If anyone has tried telemetry, what sort of current do you see ? Does this sound right?

I have motion, sound, and smoke. No recoil.

[Gerhard Michel]

Hi Nicolas,

I'm using telemetry in all my tanks, and I can say that your metered values are quite probable. Also the sensor is at the right place because so you can find out the overall consumed power of your model, which is important for the remaining capacity of your battery.

All my models show similar values: standing without sound about 1 amp, standing with sound 1,5 to 6 amps (volume is adjustable by transmitter, maximum output power 120 to 300 watts), driving with moderate sound straight forward on hard grounds 4 to 6 amps and so on, up to 60 amps (!!) when tableturning in rough grass with steel track links, rooting out the grass.

I have only one Armortek model, but the values don't depend much upon my chosen model. Therefore I think that all bigger models in 1/6 scale show nearly the same power consuming behaviour.

This is the standard screen of my telemetry, showing battery voltage, actual current flowing and consumed capacity till now:

[nikolas george]

Thats great Gerhard. Thank you for the information and for confirming that i was measuring things right.

We are off to the local common this afternoon with the Elephant (I do'nt mind digging up the grass there!!!!!). I will report on the current consumption we get there.

[Gerhard Michel]

Hi,

when you avoid nest-building like my first King Tiger, you will have moderate power consumption.......

[nikolas george]

Haha - love it! A nesting King Tiger. Did you end up with a bunch of 1:16 scale KT?

Well, Sunday was a bit too wet to run on the grass so we went out yesterday.
The grass on the common was about 3" to 4" high.

Running in a straight line - peaked at 6 amps. Spinning on the spot (one track going forwards and the other in reverse) started at around 22 amps but I guess as the grass got dug up it dropped to around 17 or 18 amps. All of this was with no sound and smoke.

Next test is to find a hill

[Gerhard Michel]

Several years ago this was the first test run with Olaf's steel track links which have a very high traction. No hill could generate more power consumption than table turning in rough grass.

[Adrian Harris]

Those figures sound close to what I'm getting with the 2009 King Tiger, which doesn't have the higher efficiency motors fitted.

Peak current at the last show was just over 30A, with sound but no smokers, running on fairly short grass.

Adrian.

[Jerry Carducci]

As I'm beginning my King Tiger project I've been experimenting with the motors and electronics. I've been wanting to use one of my
FrSky ETHOS X20 series systems, actually an X20HD system to prove it out.

I have a whole raft of telemetry sensors on the FrSky smart bus. I'll be posting a bit more on my budding thread over in the KT sub section.

Jerry

[Gerhard Michel]

I'm using telemetry also (and mainly) to supervise the temperature of motors and ESC, but mainly the single cell voltages of my LiFePo4 battery (used without a BMS). Yes, also the temperatures of motors and the voltage of each cell could be shown at the display, but much more important is that acoustic warning messages can be programmed in the transmitter, if there is a temperature or a voltage problem. So I don't have to look at my display for such informations and may drive my tank freely, and I may use the telemetry display for general information as shown above; e.g. the consumed capacity of my battery.