The new KK2 FC, info and Q&A in first post. Read it before asking a question. - Page 721 - RC Groups
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Feb 20, 2013, 09:54 PM
Registered User
Quote:
Originally Posted by jasmine2501
If it causes the motors to surge more, then it definitely will lose efficiency. Accelerating the motor uses a lot of power. Brushless motors are really efficient, but if the motor is surging and it's unnecessary to maintain stability, you are wasting energy. Think about the worst case and the best case - in the best case, your motors would run at a constant RPM and the quad would be stable. In the worst case, the motors are surging hard and the quad is wobbling - that wobbling motion is a waste of energy. The closer your gains are to 'correct' the more that wobbling is reduced - but it's still there, it's just so small you can't see it. That's how a quad copter works (it's constantly wobbling, if it wasn't, we wouldn't need the KK). So, in the middle of the gain range, you have worse efficiency than the best case.

However - depending on your particular quad, it may not make a significant difference at all. It will make a difference because you're closer to the 'worst' example than the 'best' but it may only cut your flight time by ten seconds and you'll never notice.
every wobble has one motor speeding up and one slowing down so probably net zero.
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Feb 21, 2013, 12:16 AM
5th
5th
Mediocre Pilot Extraordinaire
5th's Avatar
I didn't read it on the internet. I was inferring it myself thinking along the lines of what jasmine2501 wrote. I don't think it would be a net zero because accelleration is far more expensive than constant rotation, but I might be convinced the difference is negligible. Still, a test might be easy enough. With a multi that is fairly stable at lower than average gains and a fully charged healthy battery, run five minutes hover on the lowest gains I can control. Then charge the battery and run another 5 minutes hover on the highest gains I can control. Charge again and compare mAh used per flight. Then again, the drift in conditions and the battery alone might cause an error greater than the effect I'd be trying to measure.

It was just a thought: I have a lot of them, and often they are worthless. But some are pretty good. I think of it like Edison finding the right filament to produce a working light bulb - he tried everything he could think of. I try to examine my ideas to see if they have merit. Sometimes I'm pleasantly surprised. In any case it rarely hurts to ask those that might know more. Correct or not, it's usually productive.
Feb 21, 2013, 01:25 AM
Registered User
Quote:
Originally Posted by 5th
It was just a thought: I have a lot of them, and often they are worthless. But some are pretty good. I think of it like Edison finding the right filament to produce a working light bulb - he tried everything he could think of. I try to examine my ideas to see if they have merit. Sometimes I'm pleasantly surprised. In any case it rarely hurts to ask those that might know more. Correct or not, it's usually productive.
If your tests prove that you are correct then your conclusion is "don't fly fly with overly high gains because it reduces flight time by using too much power"?. I don't do that anyway, because for me it reduces flight time by causing oscillations that result in a crash.
Last edited by kaptondave; Feb 21, 2013 at 01:40 AM.
Feb 21, 2013, 02:02 AM
AVR Dude
Quote:
Originally Posted by --Oz--
What frame rate does the KK2 v1.5 output to the ESC's (I am guessing it's higher than standard servo frame rate do to the ESC or Servo option in the KK2 menu)?
The ESC frame rate is 400Hz.
Feb 21, 2013, 03:24 AM
numnutchris
Quote:
Originally Posted by ripmax
surely there must be a straight forward thread somewhere here?
Same place where you got the SW, I suppose:
http://lazyzero.de/en/modellbau/kkmu...ashtool/manual

You need the Flashtool, Java and some driver for your usb->atmega cable.
Feb 21, 2013, 04:19 AM
Trust me I'm an engineer!
Quote:
Originally Posted by brontide
Looks like you could clean up some ofu that Rx wiring, you only need one of the Gnd, +5v wires and the rest can just sit sideways connecting the signal wires as appropriate.

Balsa is light and at that weight it should be quite stable, but I don't know how durable that would be long term. A harder wood like basswood would give it a little more resiliency.
Thanks, yes. I have done that with my Reaktor 3d because I ran out of male-male linking cables.
I have already snapped one of the motor arms off and glued it back on. I just used some balsa leading edges from an old glider kit, as I love to use leftovers that cost nothing.
I need to replace the ply centre sections as they are inclined to split.
My next goal is to do the chuck test that involves throwing it into the air like a frisbee and then giving it half throttle and see if it stabilizes. But looking for some long grass to do it above rather than the gravel of my driveway.
The main goal was to make something very light. I could still shorten the arms, and some of the wiring. I have set up the low voltage alarm on the KK2 so I don't need the accessory unit.
And I need some more flying hours to get accustomed to which way it is pointing when I am flying it!
Still haven't mounted my vidcam on it.
Feb 21, 2013, 05:36 AM
Registered User
Del-Dredd's Avatar
From Landor

"There is still something strange: when I hit aileron left I have -104 Left, and when I hit rudder left I have +104 Left. Is this normal?
Can anybody tell me the correct settings for 9ch Tx an Kk2?
Are these settings ok?
"

I use a 9X (FlySky TH9X) with ER9X firmware.

My Rx Test values are the same polarity wise.

Rudder Left is +ve value, Aileron Left is -ve value.
Elevator back is +ve Value and throttle from 0 to 100.

As for Motor 1, someone replied to you ages back that running without props will cause one motor or other to increase in speed as the gyros are trying to get the craft level but it is not moving to level (Very basic but you get the idea).

How long is it running before it is hot, check for binding or rough bearings, if it is the type where the mount clamps onto a tube you may have screwed up to tight and squeezed the bearing, I have done that before.

Leave it powered off for a few minutes, does it spin free by hand.

Deyrick
Last edited by Del-Dredd; Feb 21, 2013 at 05:55 AM.
Feb 21, 2013, 08:20 AM
Registered User
Quote:
Originally Posted by Gilbert Griffith
Thanks, yes. I have done that with my Reaktor 3d because I ran out of male-male linking cables.
I have already snapped one of the motor arms off and glued it back on. I just used some balsa leading edges from an old glider kit, as I love to use leftovers that cost nothing.
I need to replace the ply centre sections as they are inclined to split.
My next goal is to do the chuck test that involves throwing it into the air like a frisbee ....
Man, you have way more balls and way better flying skills than I do with these things. A balsa quadcopter would never survive the first toss in my hands. In fact I admire any first-timer with the guts to fly an all-balsa ship under any circumstances. Best of luck, but if it does not work out here is what I consider the best deal going for an inexpensive but tough first multi:

http://www.hobbyking.com/hobbyking/s...dproduct=24172
Feb 21, 2013, 11:55 AM
5th
5th
Mediocre Pilot Extraordinaire
5th's Avatar
Quote:
Originally Posted by kaptondave
but if it does not work out here is what I consider the best deal going for an inexpensive but tough first multi:

http://www.hobbyking.com/hobbyking/s...dproduct=24172
Did you hear they changed that kit?
Feb 21, 2013, 12:14 PM
Registered User
Quote:
Originally Posted by 5th
Did you hear they changed that kit?
Nope.
Feb 21, 2013, 12:29 PM
Registered User

Incredible


Incredible. Even a totally new multi rotor pilot can fly with the KK2 board. I am fascinated.

Tricóptero Tricopter V (1 min 58 sec)


It's a kind of warranty of fun.
Feb 21, 2013, 12:30 PM
HeliHarry
harrym's Avatar
Quote:
Originally Posted by 5th
Did you hear they changed that kit?
You mean this one...
http://www.hobbyking.com/hobbyking/s...B_Version.html
Feb 21, 2013, 12:44 PM
Registered User
Quote:
Originally Posted by harrym
I bought the one without the integrated PCB and added the power distribution board which has the battery and ESC power connectors installed.
Feb 21, 2013, 01:06 PM
Registered User
taz007's Avatar
Quote:
Originally Posted by Steveis
Taz007, check out my blog. There is a V1.4 with a lower gyro limit of 490 for you. However, I don't hold out much hope as your gyro z looks too high. But if you don't send the board back, it's worth a try.

https://www.rcgroups.com/forums/show....php?t=1836243
Cheers my friend but sent it back. just waiting to see if its covered by the 30days cover, But going to buy another KK2 next week .

Thanks again
Feb 21, 2013, 02:22 PM
Registered User
Quote:
Originally Posted by Del-Dredd
From Landor

"There is still something strange: when I hit aileron left I have -104 Left, and when I hit rudder left I have +104 Left. Is this normal?
Can anybody tell me the correct settings for 9ch Tx an Kk2?
Are these settings ok?
"

I use a 9X (FlySky TH9X) with ER9X firmware.

My Rx Test values are the same polarity wise.

Rudder Left is +ve value, Aileron Left is -ve value.
Elevator back is +ve Value and throttle from 0 to 100.

As for Motor 1, someone replied to you ages back that running without props will cause one motor or other to increase in speed as the gyros are trying to get the craft level but it is not moving to level (Very basic but you get the idea).

How long is it running before it is hot, check for binding or rough bearings, if it is the type where the mount clamps onto a tube you may have screwed up to tight and squeezed the bearing, I have done that before.

Leave it powered off for a few minutes, does it spin free by hand.

Deyrick
I have swapped the plugs on KK2 board from CH1 (motor 1 & esc 1) with CH2 (motor 2 & esc2) and the problem transsfered from M1 to M2. So I understand that the board increases the rpm's. CH1 has a problem or it could be like Deyrick said above.
Motors and esc's are ok.

About the hot motor, it is hot compared to others.
I thing that it is getting hot because it spins faster than the others.

I have checked also the screws from motors. They are ok and motors are spinning easy by hand.