ELEV-8-v3 Full-System-Check

nomad

hello

today i make my first Full-System-Check indoors with my new Quad with propellers,
according the instructions step 28.
for security: the landingGear was with 4 heavy book blocked.

HipHipUrray
its running, no problems nothing crashes

but one thing:
in the instructions reading "and the propellers will spin at low throttle"
- what understand you under "low throttle" ?

in my opinion: Verry fast throttle (spinning).
where can i change this in the GroundStation software?

and as attachment: firstQuadTest-1509-324.jpg

the quad-frame is a modified tarot-650-sport frame
diameter 560mm, high total 180mm

Thanks for tips and hints
best regards
nomad

Publison

In "System Setup" in the Ground Station software, the throttle RPM can be changer, but it will not go below 800 RPM. It is my understanding that the props will spin when the Quad is Armed, just to let you know it is armed.

JasonDorie

ESCs for aircraft are not meant to spin at very low RPM. They do not have sensors to detect the orientation of the output shaft, and instead use what's called back-EMF (generated current) from the coils of the motor itself to determine when to change the currently energized coils. That doesn't work at very low RPM.

The Elev8-FC, by default, spins the propellers when the unit is armed. Not enough to generate much lift, but enough to prevent the propellers from stalling if you ever put the throttle stick at the lowest position during flight, and also enough to remind you that it's running and will respond to the throttle if you bump it.

In the GroundStation software, you aren't changing the "RPM", just the length of the pulse sent to the ESC at the lowest throttle setting. Standard servo / ESC pulses range from 1000 to 2000 microseconds. You can make the low (armed) value match the low (disarmed) value, which will mean that the propellers do not spin when the unit is armed, but I don't recommend this.

Publison

JasonDorie wrote: »

In the GroundStation software, you aren't changing the "RPM", just the length of the pulse sent to the ESC at the lowest throttle setting. Standard servo / ESC pulses range from 1000 to 2000 microseconds. You can make the low (armed) value match the low (disarmed) value, which will mean that the propellers do not spin when the unit is armed, but I don't recommend this.

In Ground Station 1.0.3, You can not enter a value less than 800. Is there another place you can do this?

JasonDorie

A value of less than 1000 is typically out of bounds. The limits are there intentionally to prevent users from entering values that will make the hardware fail. The servo driver in the Elev8-FC code itself will lock up with a value of less than 500.

To an ESC, which takes standard servo pulses, a pulse length of 1000 microseconds is the lowest "legal" throttle value, whereas a pulse length of 2000 microseconds is full throttle. You run the throttle calibration to get GroundStation to tell the ESCs what your lowest and highest throttle values are, so they aren't doing anything weird like auto-detection of the throttle range. There's no reason you should need to output a value of lower than 1000, but I allowed from 800 to 2200 because some servos allow that range.

So why do you need to specify a throttle pulse length of less than 800 micros?

nomad

hello
@Publison + @JasonDorie
thanks for your answers.

i think, i dont change the values, its too dangerous, if i flight and the
throttle is on the minimum, i want no crash.
best regards
nomad

geo_leeman

@nomad - You'll want to leave the setting alone probably. The spinning when armed is not enough to fly obviously, but is a good safety measure to make sure you don't go near an armed aircraft. Even at low RPMs the propellers can do damage, so make sure everything, including your hands, are clear before arming. Good luck with your first test flight!

nomad

hello
@geo_leeman
excuse my late answer:
i stand about 1 meter from the quad.
and the quad was locked with bigBooks....
regards nomadd