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Posted by represent | Mar 03, 2014 @ 07:45 PM | 11,582 Views
Originally Posted by Dodge161 View Post
For the KK2 board. Am I right in thinking that P gain/limit settings are adjusted when using the auto level function? If so... Are the I gain/limit functions adjusted when flying with auto level switched off? Do I gain/limit setting make any difference to flight when auto level is activated? Without quoting the mathmatical effects of P and I gain can somebody give me a real world description of how changing the I gain settings will affect flight thru the 3 axis. Also for the P gain please.

Self Level has a P gain setting. In SL mode, both the normal and the additional SL gains are active. You will get an oscillation if this SL P gain plus the normal roll/pitch gain (P, ?I?) combined is too high. Once you hit oscillation and back it off, I hear that if you want SL mode to react even quicker to the stick, you should increase the SL limit.

You need to understand the mathematical descriptions of the P and I gains. They both work based on how much error there is.

P gain says to run the motors proportionally to the error. If the copter is commanded to not rotate, and you grab it with your hand and rotate it at 5 degrees per second, you will get the motors spinning to fight the rotation with some amount of resistance. If you double the P gain you will get twice the resistance. Or if you rotate it twice as fast you will get twice the resistance. It only fights while the rotation is occurring. So if you rotate the...Continue Reading
Posted by represent | Oct 15, 2013 @ 02:25 PM | 11,380 Views
re: discovery pro BG horizon shift:

One thing you should try is Gyro Trust. I have UNCHECKED Skip Gyro Calibration on Startup. Then set Gyro Trust to 255. Now go to your flying site. Plug in the battery and immediately stand back and don't move, to let the gimbal calibrate its gyros. Now take off and fly.

I got amazing results by doing this. The horizon shift I've seen since I did this has been minimal. Before it would go completely off (45 degrees or so) just by yawing around. Now I can fly at full speed and make banked turns and it will keep the horizon horizonTAL.

Let me know if this helps anyone else!
Posted by represent | Oct 08, 2013 @ 08:26 PM | 11,667 Views
Aug 13, 2013, 06:22 AM
#3738 Report
T J Gilbert
The Devil Is In The Details...

507 miles from you in
United States, MS, Ridgeland
Joined Feb 2009
3,648 Posts
Originally Posted by godwisper
good one
I have read on other forums about people having an AUW of arnd 2kg with battery and are using 4s and 8inch props....
will this work ?
uhm its difficult to remove any of the fpv stuff or gimbal to be honest and just got the kit brand new assembled
Here's what I, personally, have successfully done.
Remember that there are dozens of ways to skin a cat.

When I was flying a gimbal + GP2 on my F450, it had an AUW of ~ 1550g.
My F550 with servo gimbal + GP2 was 2560g (6.7% over recommended)
My F550 now with H3-2D + VTx + iOSD + misc is 2630g (9.6% over recommended)
I have always used 4S lipos (3300mA on F450 & 5000mA on F550)
On the F550 + GP2 I used SunnySky 2212 motors that are slightly better (opinion) than DJI.
On the F550 + H3-2D I am moving up to SunnySky 2216 motors to get a little more lift.
Not because of poor performance.
Because I want the reassurance that I have plenty of power carrying the $$$!
I generally always use APC 9x4.7 SF props and eCalc tells me I should be OK.
My motors get a little warm to the touch & I monitor them like they are prime concern.
I can't (& don't) throw a camera platform airframe around like a hotrod.
I have a bare F330 and a Phantom for that.
My old F450 is now my FPV platform.

To answer your specific question, I think I'd try 4S + 8" or 9" props.
Check your ideas with eCalc.
eCalc is conservative, so if it says OK (or marginal) your plan should work.

Lastly, I'm sorry that you are discovering that your airframe is having problems with carrying everything.
If I recall correctly, you went with budget motors because of the expense involved and what you had to spend on your airframe.
With what you wish to carry, you'll need to be the judge of whether or not that was wise...
Posted by represent | Sep 04, 2013 @ 10:46 PM | 12,102 Views
Originally Posted by rob38

The s style sucks on my analyzer to

Ground problem. Lol

Bulding a invered V. Or dipole

Rob - there is more going on than what your analyzer shows. The "Sander style" antenna uses the receiver case and ground wires as the counterpoise and thus your analyzer only tells part of the tale because it has none of this. Of course, it does show it is a crappy antenna.

On the other hand, Anthony (Immersion RC's silent developer) and I had a very lengthy discussion about this at the Canadian FPV fly-in and we came to the conclusion that the monopole antenna causes RFI issues to be amplified as the ground wires that carry the RFI now have a direct path to the antenna port! This is what has been causing EZUHF users to get such crumby range.

Posted by represent | Sep 04, 2013 @ 09:58 PM | 12,363 Views
Rx antennas expplained.. sort of
Originally Posted by daveyedgar
sweet! thats great to know thanks! sometimes i would aim my antenna at the plane like looking down the barrel of a rifle hehe.

Oh and since we are on the subject. I understand that the length of the antenna at the receiver is also significant, made that length to be "tuned" to the receiver and transmitter. Is that true?

and the antenna should be layed out flat and not coiled or wrapped or anything correct?
Yes all true. Your antenna length should be: 2808/your frequency in MHz = Ideal antenna length in inches. So your antenna should be 39 inches long.

The antenna should be relatively straight and flat. You can let the end dangle off the end of your wing and it won't hurt it.


Imagine a doughnut forming around both your rx and tx antenna. This is the radiation pattern. Now imagine that there are "ribs" along the circumference of the donuts. You want these "ribs" on the TX and RX to line up with eachother. If they meet at a 90 degree angle the signal is almost completely lost! This is why pointing the antenna at the airplane is simply the WORST thing you can do for radio range. The signal comes out the side of the antenna, not the top.

A quick tip:

If you place your 72 MHZ receiver antenna in a different orientation than your FPV TX antenna, it knocks out a huge amount of interference thus increasing your range.

The best set up for...Continue Reading
Posted by represent | Sep 04, 2013 @ 05:49 PM | 14,490 Views
TBS Discovery Epic 7km FPV Flight (Full version) (13 min 52 sec)

Obviously this isn't my own 550. But looking at his specifications and equipment, I think with the right battery (and Fresnel zone) I could match his flight with my own 2.4ghz video system. Would I want to? Probably not. I like keeping possession of my gear.

From the video description:
Published on Sep 4, 2013
Yesterday I improved my personal distance record in long range FPV (Long range for a multirotor, of course) with my TBS Discovery. Now it's 7 km I believe this is the farthest flight ever made with TBS Disco.

Next time will try to reach 8km. Enjoy the video!


TBS Discovery frame + TBS Core
TBS69 FPV Cam + 2.4 ghz Lawmate VTX (TBS Tuned 800 mWt) with Circular Wireless Skew Planar Wheel
Lawmate VRX with 2.4 ghz 14dbi patch antenna
Graupner MX-20 + EzUHF TX& 8ch Diversity RX
900kv T-Motor, 10x5 graupner e-prop, Two 4s 4200mah Kypom batteries in parallel
GoPro Hero 3 BE
Foxtechfpv Dv-02 (My ground station DVR)

AUW is 2.1 kg.
Posted by represent | Aug 26, 2013 @ 08:16 PM | 12,093 Views
This is just a clipboard of posts where I keep information I am using and don't feel like writing down. Browse at your own risk.

Originally Posted by ZACATTACK
Snipeworm...when your calculating things on multicopters, a 1.8:1 to 2:1 thrust to weight ratio should be your goal for a good handling & hovering aircraft. So if your craft has an AUW of 3000grams or 3Kg your motors should be producing 6Kg or 6000grams of thrust minimum or a little more...If this means going to 5S if the motor can handle it, so be it...If it means going to a 12" prop on 5S, So be it..Will the frame handle these mods?? NO?? Look for another frame that will. All these things must be computed and mapped out to reach your lifting weight and flight time goal. Once you go below that ratio of 1.8-2:1, your start loosing period.
Just saving the above for future reference. Thanks ZA

2. With telemetry, you can fly to 14.2v under load without problems. The batteries will come back to 14.8v resting.

You'll see that when you charge them back you're putting about 78-80% back into them (MAh count) which is the best practice.

3. Quote:
Originally Posted by WallyWumpus
I have a 550 with 1038 props, stock motors and ESC's, gimbal plus gopro, flying weight is 2.2kg. I use a 4s nanotech 4500 battery, and I land at 14.0v, which occurs at 11 mins. Voltage recovers to 14.3v before charging.
I usually discharge a 4S pack to...Continue Reading
Posted by represent | Aug 24, 2013 @ 01:27 PM | 20,169 Views
Represent here. Okay let's do this. I don't have a ton of time on my hands, so regretfully I am not going to make a video for you guys just yet- I might in the future though. This is basically way too long to do a video. What I am going to do is walk someone through adding FPV to their 450 or 550, narrative-style. I wish someone had done this when I was getting started, it would have saved me a ton of time. I'm not going to explain everything, but I will try to hit the high points and add any necessary caveats. Let me add that I am pretty OCD on researching things like this- I spent about a month reading at night and on the weekends about how to do this right. So what I am about to tell you is one of the right ways to do it, IMO.

So the first thing you have to realize when doing this is that you have choices- many choices. One of the most important choices (Choice "A") is how you are going to source your FPV gear/setup-
(a) do you want to be thrifty and piece your system together from cheap parts that may or may not work bought from across the internet? (i.e. Hobbyking)
(b) do you want to spend a bit of money and get a "ready to fly" FPV system that might work OK? (i.e. ReadyMadeRC's kits)
(c) do you want to get an FPV system from one of the FPV gurus himself, IBCrazy?

Because I wanted my system to work the first time, and because I don't have time on my hands to experiment and because I have no wife to prevent me from...Continue Reading