[Dicara]

Hi,

I just had my maiden flight with my new Hex and got 4x 8.5/9 min flights each one with an 1.3ah 4S lipo, its a Spedix S250ah, with a revo controller. and i have a few questions if that's ok.

1. when its low/touches the ground, it seems to suddenly shoot up into the air, you can hear the Motors jump up in speed drastically as well. is this normal? and is it possible to disable this.

2. when the battery runs low, is that a way to set it so that it once the battery reached a certain level it reduces the throttle/lands. the speed controllers i have reduce the throttle when the battery runs low and just cut out once they reach a point. but since i was keeping it low/in a imaginary box area over at the park, i didn't notice the speed reduction and they just cut out and it dropped and broke 2x props. which losing a prop or two isn't an issue, but is the battery got damaged from it just dropping out the sky, it could become one.

i do have a volt/amp meter on it and it is working/Calibrated with my fluke meter so it reads fairly accurately

there will Probably be more questions :p , but these are the main ones i can think of at the moment

Thanks

Justin

[NicholasDavid]

3.3v per cell is danger zone for damaging a 3s or 4s pack. You want to land at 3.5-3.6v and your batteries will last many cycles.10.5v is lowest for 3s and 14.0 is lowest for 4s I ever go.  With 3s 1300's batteries I get about 4 minutes. And after I've landed and unplugged they come up to 11.1-11.3. Which is almost storage and is easy on the batteries, so they could go longer. On 4s I typically use the same flight times 4-4.5 min. But that's discharging as far as I ever want to fly them to. 14.0v is 3.5 per cell. With my current level of flying I don't put too much strain on the batteries. But as you progress to hard acro flying and racing, expect total flights to only last 2 1/2-3 1/2 minutes. Using a voltage buzzer to start going off at 3.5-3.6v is what I use. And time your flights again to see how long you can safely stay flying. Some like an on screen display so they can always see the voltage and land when appropriate. As far as an auto return to home when voltage is low....that's what phantoms do. And other GPS assisted copters do. The racer/acro quads we are talking about here don't need that  heavy junk. Just get an OSD(on screen display) or use a voltage buzzer and timer. That's all you need

If you have it set so motors spin upon arming then yes it's jump up is normal.
There is a check box in the stabilization tab under basic I think that reads zero Intregal at low throttle or something like that. Make sure that's checked.

Also if you have always stabilized when armed "on" the it will do this as well.

I would make sure that "zero I at low throttle" box is checked. And have it set so your motors stop at zero throttle.
I have mine set so I arm and disarm on a Switch. So I can get as low as possible then just disarm and it drops a few inches.

[Dicara]

Hi Micholas,

Thanks for the reply.

For the low batteries, i don't mean for it to return home, i was thinking along the lines of when the batteries reach a set level, i.e. from your example of 14.0 volts, so when they reach 13.8/9, the chopper goes " NOPE, batteries are to low fool, I'm landing now and right here!" type thing


for the jumpy bouncy thing, i have the motors set to nothing happens when you arm, they only start up when you apply throttle. but thats not the issue.  the issue i'm having is when its already in flight, if it does more that brush the grass, without me doing anything it will just rocket up by about 3 to 6 feet. and you can hear the motors increase a lot as well.

the best way i can think to describe it is it's like it has a floor limit set and if it goes beneath that it takes control and forces you up. it even does it when trying to land. so unless i cut the throttle at lease 1 to 2 feet above the ground it will bounce/jump up even if i cut the throttle just as it lands, it will jump up, then acknowledge the throttle cut, at which point it will just drop and flip/crash. which sucks as that's the only reason i have broken a prop's so far



Edit:
Just looking throught he settings on the coppter, and in the Takeofflocation, it has a Down set to -1.56757 M. where all the others in this box are set to 0 M, could this be anything or something else entirely, i'm searching google for what this setting it. but so far all i can find is its to do with return to hom/arming location. but not what each setting is.

[Dicara]

with a bit of puckering, i managed to recording the bouncy issue :S

Landing bouncy bouncy

This one, i cut the throttle just as it landed/touched down, but it decided nope, i want just a few seconds more

Just bouncing around


This one i just left the throttle alone just to see how many bouncy bouncy it would do.

[jbarchuk]

This one i just left the throttle alone just to see how many bouncy bouncy it would do.

This is a very common question/problem.

I'll tell you this for a fact -- given enough space, as long as you never shut off the throttle it will keep bouncing till the batteries run out.

That said, both of your vids were 'improper' launches, and both vids never gained true 'flight.' In both vids the hex never got out of the ground effects space which for various size rotary winged vehicles might be a couple of feet to 6-8 feet.

Please read this thread where I explain the problem you're experiencing. The -symptom-of the original question was different, but the -cause- was the same. https://forum.librepilot.org/index.php?topic=907.msg6689#msg6689

If what I describe seems to make sense then try flying your hex again, but fly it 'properly' up in free air not in ground effects. You should get completely different results. If the way I described things doesn't make complete sense then ask again here and I'll try again.

[Dicara]

Hi Jbarchuk,

Thanks for the link and reply.

for the improper launch, yep, but in my defense i was trying to recreate the issue while holding my phone to record it, so trying to fly one handed while the other hand is busy, with only 1 days flight experience so im just happy i missed the pond

when in the park field, i'm guessing my launches are also improper as i had been letting the motors spin up for about 30 sec, before taking off, but i haven't noticed any issues. but going by your post in the other thread, that can confuse the FC, so tomorrow as i'm off work, i'l try launching straight away to see what happens.

for the bouncy bouncy , i don't see it while flying or hovering low, even brushing the grass is ok which is about 1 inch at most from the ground, it only seams to happen when it actually touches the ground. which makes landings a bit difficult as touching the ground is a bit hard to avoid when landing .

i've rebound the arm/disable to a  a switch on my transmitter to its just on/off instead of on the flight sticks, so as suggested Nicholas earlier in this thread  but i haven't had time to test it yet, but disarming it just before it hits the ground seams a bit wrong to me, and i'm worried it i accidentally hit it while in the air, but since i haven't tested it yet il give it a go and see how i feel about it afterwords.

[jbarchuk]

Doing any better lately?