Originally Posted by microdave

I noticed stepflyer does not seam to have any trouble using kk2 in cold weather. I have a t-copter with 1.4 FW. It likes to jump up and down evenly with all three motors. If I run it in the house it does not jump. Outside temp @ 20 deg f. I have tried different H. damp settings. Should I keep trying with H. damp or does anyone have any other ideas how fix the jumping. Everything else works perfect.

At first needed to lower a bit settings, but after some time quad was able to fly fine with almost old setup.
At the end my finger was freezing but quad start to fly normal ( got warm I suppose).

Watch for snow melting after flight, put it in room and do not power it until 100% dry.

Video, you can see oscillation at first and got better after some tuning.

x666 KK2 1.5 winter flight with cold wind (7 min 51 sec)

Hard to fly when pilot is freezing.

Originally Posted by srepfler

At first needed to lower a bit settings, but after some time quad was able to fly fine with almost old setup.
At the end my finger was freezing but quad start to fly normal ( got warm I suppose).

Watch for snow melting after flight, put it in room and do not power it until 100% dry.

Video, you can see oscillation at first and got better after some tuning.

http://youtu.be/k02mJluA8nc

Hard to fly when pilot is freezing.

Did you leave your quad outside for some time so gyro's is settled to temperature.

I always live my quad outside for about 20min and then fly. I don't need to set anything.

Originally Posted by er9xuser

Did you leave your quad outside for some time so gyro's is settled to temperature.

I always live my quad outside for about 20min and then fly. I don't need to set anything.

My settings was too close to limit ( right before wobble occurs), if I leave little lower no tuning is necessary, but like to play with it and got most as possible.

Originally Posted by srepfler

My settings was too close to limit ( right before wobble occurs), if I leave little lower no tuning is necessary, but like to play with it and got most as possible.

The problem I had in the cold looked more like glitching of the throttle signal, as all motors were affected synchronously. Very shorts bursts, about once a second.

Fred

Originally Posted by flarssen

The problem I had in the cold looked more like glitching of the throttle signal, as all motors were affected synchronously. Very shorts bursts, about once a second.

Fred

I think this is ESC problem. Maybe your esc's don't have external oscilator and are prone to temperature drift.

Originally Posted by er9xuser

I think this is ESC problem. Maybe your esc's don't have external oscilator and are prone to temperature drift.

They don't (Plush 12A) have that, but all four behaving 100% identically?

Fred

Originally Posted by flarssen

They don't (Plush 12A) have that, but all four behaving 100% identically?

Fred

I thought maybe the ESC's or one ESC could glich in the cold and cause the board throttle to up.

I have tried leaving the tri outside all night, it still jumps up and down. I jumps up, then without moving the throttle, it goes back to the altitude before.

I only have three motors. The tail motor has a different Esc than the other two. The tri moves up so evenly it is hard to belive one ESC could cause this.

I have tried changing the settings in the FC under self level. It does this jumping in self level, so changing the settings in pi editor won't effect the self level, will it?

It's jumping because it thinks it's falling; if you have exhausted your PI/P/HD tuning then I would also investigate dampening the KK2 board from jolts, it may just be that vibrations are getting the better of it.

It came to me last night that with these control boards (both this KK2 and the MultiWiiPro) you get a cute little frog out of the box that works just fine. It seems that everyone wants to make a lizard out of it. But one slip up and that cute little lizard turns into an alligator and bites you in the ass!

I have managed to get myself so confused trying to flash the KK2s and reprogram the MultiWiiPros that I am having to take a break before I cook the alligator for dinner.

Sudsy

Originally Posted by microdave

The tri moves up so evenly it is hard to belive one ESC could cause this.

You would probably see it move up similarly if you gently pushed up on just one arm while hovering.

Things to try:
- Reduce your gains. It is well known that oscillations cause height changes because ESC's (especially unflashed ones) spin up at a different rate than they spin down.
- After reducing your gains, turn off your auto-leveling for a test.
- After reducing yoru gains, turn off height dampening for a test.
- Reduce vibrations to the KK2. (balance your props, mount KK2 on vibration dampener)
- Starting warm in the house, get it ready, take it outside and fly it within 5 seconds (or fly it through the door). If it happens immediately (parts still warm) then it is air density related. If it takes more than 30 seconds, it is possibly cold parts related. You might insulate your KK2 to extend the time it takes to cool off. Wrapping in plastic wrap would make it take significantly longer to cool off.

Originally Posted by Sudsy

It came to me last night that with these control boards (both this KK2 and the MultiWiiPro) you get a cute little frog out of the box that works just fine. It seems that everyone wants to make a lizard out of it. But one slip up and that cute little lizard turns into an alligator and bites you in the ass!

I have managed to get myself so confused trying to flash the KK2s and reprogram the MultiWiiPros that I am having to take a break before I cook the alligator for dinner.

Sudsy

Good analogy. I also have one that can compare it to our spouses but I will refrain from that one as everyone knows that "Santa is always watching".

I did that with my FreeFlight controller. Tried to re-flash so many times between the default firmware and MultiWii that I bricked it. Such a nice $50.00 board turned into a $50 piece of junk.

I hope I am more gentle with my new Crius All In One Pro.

Originally Posted by theothercliff

You would probably see it move up similarly if you gently pushed up on just one arm while hovering.

Things to try:
- Reduce your gains. It is well known that oscillations cause height changes because ESC's (especially unflashed ones) spin up at a different rate than they spin down.
- After reducing your gains, turn off your auto-leveling for a test.
- After reducing yoru gains, turn off height dampening for a test.
- Reduce vibrations to the KK2. (balance your props, mount KK2 on vibration dampener)
- Starting warm in the house, get it ready, take it outside and fly it within 5 seconds (or fly it through the door). If it happens immediately (parts still warm) then it is air density related. If it takes more than 30 seconds, it is possibly cold parts related. You might insulate your KK2 to extend the time it takes to cool off. Wrapping in plastic wrap would make it take significantly longer to cool off.

I would also check your solder connections for any cold solder joints or loose/frayed wires. Bullet connectors are notorious for that.

I have a small quad, 20-26m motors, 8x4 props, 18a turnigy plush esc. I am currently using p gain 100 and I gain 40 for roll/ail. I have never seen anyone using so high values in this thread (20 cm arms, means about 40 cm motor to motor) but it does not wobble or anything. It's really precise instead, maybe too much.

The tuning guide tells to increase p gain until it starts wobbling then go back a little. I think I can reach a p gain of 130 - 150 if i do that. Isn't it strange ?

Originally Posted by davibe

I have a small quad, 20-26m motors, 8x4 props, 18a turnigy plush esc. I am currently using p gain 100 and I gain 40 for roll/ail. I have never seen anyone using so high values in this thread (20 cm arms, means about 40 cm motor to motor) but it does not wobble or anything. It's really precise instead, maybe too much.

The tuning guide tells to increase p gain until it starts wobbling then go back a little. I think I can reach a p gain of 130 - 150 if i do that. Isn't it strange ?

Seems reasonable if your ESC's are responsive.

Are you running flashed ESC's or a high KK2 refresh rate? Either of those would put you in the "very responsive" category.

I suspect that most of the lower rates you have seen posted have been for unflashed ESC's and running a slow KK2 refresh rate.

Originally Posted by flarssen

Since you ask, I flashed mine to 1.5 yesterday. I tried it outside (-8C) and had some strange hunting on the throttle, like a combustion engine with rough idle. No movement around the three axis, just jumping up and down. Same problem both with and without self leveling on. Never had this problem earlier. I tried it in my basement later, and it worked OK, so it could be a temperature issue. I noticed some high fq oscillation, but that could be caused by the self leveling settings, which I haven't tuned yet.

Fred

Fred - you are not alone and while I feel sorry that you have this problem as well, I am relieved that I am not alone.
I built and flew my quad for a few flights - KK2 from HK and I believe it came with V1.4. I had zero issues and really liked it - very stable and smooth.
Then I made some changes, added my FPV gear and flashed to 1.5 and ever since then I have had a glitchy throttle. Mine originally was exactly as you describe - jumping up and down but that settled down to a periodic boost or loss of throttle. I can take off very smoothly and hover around a bit, but after 30 seconds or so it will periodically lose all throttle and drop straight down a couple of feet before recovering nice and smoothly. More rarely it will give a boost of throttle and jump straight up a couple of feet before reducing to a normal throttle level. I have tried everything I could think of.
First of all - the FPV gear was removed to eliminate interference - no change.
tried 2 different Rx's. (I am flying on 72mhz)
I found a poor connection on the rudder esc signal wire and fixed - no change.
I left the quad outside for half an hour before flying - no change.
Balanced props, reflashed (but used V1.5 again) - no change.
Checked all connections visually and electrically - all good.
Currently I have taken my quad apart (from when I checked all connections) and it is shelved until I receive a new KK2 (which is on its way) to confirm or eliminate that as the problem. If the new KK2 does not resolve the problem then I am left with the spectre that there is an issue with my radio (Futaba 7CAP).
I guess I should reflash my original board to V1.4 as well to eliminate that as a suspect....

And to theothercliff - thanks very much for your suggestions when I was having my issues. Unfortunately it still was not resolved. Sometimes it would seem to be as it flew nicely for a minute or so but then suddenly whoops! a drop of 2 or 3 feet.