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Help!! Problem with H-Quad and KK2 I am at my witts end

#1
Ok some back story, I am a noob to multirotors but really want to fly one. I built a Flitetest H-Quad, DT-750s, Redbrick 30 esc's, 2200 3s turnigy and the famous KK2 board flashed with 1.6 firmware. I am useing and older Futaba 6 ch with a tactic anylink conversion, the radio is a non computerized one so I am limited to what adjusting I can do. I quickly figured out that I needed some expo but not having that luxury I chose to set up a 50% low rate on my dual rate switches for aileron and elevator I dont have dual rates for rudder and I was getting along with it anyhow.

Ok that should give you enough background, I was just getting to the piont where I could hover and was starting to work on moving how and when I wanted to. Sunday I was out with the quad it had gotten up to about 25 feet high and had drifted over my house. I began working on getting it back over the yard gave it some aileron to slid it over and it suddenly dropped its left side and promptly fell out of the sky I had only been up for about 2-3 minutes. I retrieved it finding somewhat minor damage made the repairs and came back out agian that evening again about 2-3 minutes of flying and it did it agian from about 20 feet up. So I am running all kinds of reasons through my head, none making sence to me, again no major damage, began repairs again left it until the next morning to try again. I went out again in the morning and had the same results yet again only this time I was only 6 feet up so no damage this time. Well I had no time to worry about it then off to work I go. I puzzeled over it all day to no avail. Well I just went out again tonight and was out flying up a storm finally getting comfortable with it did some basic manuvers everything seemed great I had been up the longest yet and was doing great when suddenly, yep here we go again, it does a sideways summersalt and down it comes. So once again out comes the glue and ply and the repairs begin again. By the way I was on auto level during every incedent and the battery voltage was never too low.

So here are my thoughts, is it possible the KK board cant handle the reduced rates? I have ordered a new radio, Turnigy 9X so I can dial in expo among other things. Could auto level not be handleing it, the lowered rates, I have to use it as I am not good enough yet to fly without it. Could it be a bad board? I have a couple of new ones on thier way from HK. I will be honest and say I dont know for a fact that it always dropped the same side but I think so. Could I be haveing ESC problems? Could it be a problem with the new flash, I have looked around and cant find any mention of anyone having a similar problem.

Someone please help I really want this to work. Thanks
 

FlyingMonkey

Stuck in Sunny FL
Staff member
Admin
#2
My first thoughts are it's either an ESC issue, or you've got a loose bullet connector.

I've had the same symptoms and it was due to loose wiring.

Also make sure you don't have a bent prop shaft, and that you have eliminated as much vibration as possible.
 

Tritium

Amateur Extra Class K5TWM
#4
I think the RedBrick ESC's are factory programmed for LiPo cutoff voltage (all mine have been). You might be seeing enough voltage sag to trip the cutoff. It needs to be set for NiMh type batteries.

Thurmond
 
#5
Trituim and PaulT, thanks, I thought I had them set but I will check agian. That makes some good sence because the voltage was close to 3.7v per cell when it does this and with the voltage draw of the motors it may have been lower than that in flight.
FlyingMonkey, I am fairly sue the wieing is good as it doesent show this problem until a couple of minutes of flight. And as to vibrations I did have a bad prop but dealt with that before the last flight so I dont think that is it but its a good thought.
 
#6
Ok so I just went and reset my ESCs, the battery type may have been wrong I cant be sure. So anyhow I took it out and decided not to use the Self Level and I flew around through a battery, at least down to 11.4v and had absolutely no problems this was maybe about 5-7 minutes. So feeling that I may have it finally whipped I switched batteries and decided to try the Self Level again and low and behold it falls out of the sky within a couple of minutes. Okay multirotor whizzes what gives, help a brother out. I am thinking of reflashing the board to an older version maybe 1.4 and see what that does. So what are you thoughts.
 

Tritium

Amateur Extra Class K5TWM
#7
Unfortunately I have heard tales of redbrick problems on multicopters from more than one individual (might be your issue, might not as some RedBrick work OK when another batch doesn't. They are ALWAYS changing the design of the RedBrick series). The best ESC's to use would be a SimonK flashed one. Another to use stock that has fast timing is tne Hobbywing Skywalker series and of course the HobbyKing "Blue" series esc (it's also SimonK Flash-able).

Thurmond
 
#9
Tritium, Yes I think thats it. I was playing with my quad this morning and noticed that if I brought the power on until it just sat and basically ilded that the #4 motor would slowly speed up until it would begin to lift off, last night after I changed batteries I also noticed that #4 had trouble starting and staying in sync with the others. So I now believe I have a bad ESC and it is shutting down #4 motor hence it falling to the left when it has and episode. I think rather than fix the effected one I will just replace them all with something else. I would like to use Plush 30s but they are never in stock so maybe the HK Blue 30. Does anyone know how low in amps I could safely go with these motors they are suppose to have a max draw of 18 amps with an 11x8.4 whish is what I am running. I was thinking about trying a 20 amp that was capable of 25 amp surge but I think that may be getting too close. What does any think of the HK SS series I was thinking about the 25 30 I have some of them on hand? Thanks for all the adivce so far.
 

Tritium

Amateur Extra Class K5TWM
#11
#12
Tritium, I do indeed live in the US almost dead center to be exact, just a bit west of BFE, LOL I think I am going with the HK Blue series 30s, from what I have found they can be flashed if I so decide but like yourself, others have said they are pretty good in stock form, I'll just make sure I get a couple of spares just in case. I have to admit I had my doubts about the Red bricks when I started but made the mistake of trying them anyhow, so it looks like it will be down for a couple of weeks, oh well I guess I'll get my tricopter out anduse it for the time being. I want to thank all who offered their assistance it has been greatly appreciated.
 

Tritium

Amateur Extra Class K5TWM
#13
Tritium, I do indeed live in the US almost dead center to be exact, just a bit west of BFE, LOL I think I am going with the HK Blue series 30s, from what I have found they can be flashed if I so decide but like yourself, others have said they are pretty good in stock form, I'll just make sure I get a couple of spares just in case. I have to admit I had my doubts about the Red bricks when I started but made the mistake of trying them anyhow, so it looks like it will be down for a couple of weeks, oh well I guess I'll get my tricopter out anduse it for the time being. I want to thank all who offered their assistance it has been greatly appreciated.
Tell me about it. I have about 7 RedBricks on hand at 50A ea. Great for airplanes as a general rule and I guess great for helis if you believe the advertising but many times they do not play well in groups of more than 1 at a time. I had originally purchased 3 for a tricopter (my first) and then decided quad so ordered another. To my surprise HK had dropped the LARGE red heat sink from it and wrapped it in heat shrink. So I tried again to find an older one with the heat sink and did but again it was marked with the same part number but was very different than the originals. I have given up on red brick BUT I currently have the orginal 3 on a new tricopter I am working on. I will report any esc issued.

You wont go wrong with the Blue 30's. (unless they change them too ;) )
Just remember that the blue 30's do not have all the pads for flashing in a single convenient location unless the design has changed. I, therefore, HIGHLY recommend the HK flashing tool they have overpriced for about $20 (it should be $5 but they think you are going to use it to make money and price accordingly)

Thurmond
 
#14
Well I finally got my replacement ESCs, the KH Blues were out of stock by the time I made my mind up but the Plush 25amps were in so I got them instead. Man what a difference my quad flys great now. I also got the Turnigy 9X radio I had ordered and that made setting up and adjusting it all out much easier as well. As a side note I also have a Tricopter I was attempting fly with, an I86 board, I just replaced it with a KK2 flashed to 1.6 and it is much more managable as well. My hat is off to Kaptinkuk he has developed one fine pice of equptment there. So I am finally officially a member of the Multirotor club and love it, with a bit more practice I may even consider myself a full fledged Novice, LOL. Thanks to you all for the help you gave it is much appreciated.