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Jul 27, 2011, 02:58 PM
Human Being
sounds like you have a real frankenheli going on there, but at least it's alive bwa ha ha ha

For me, my V400 is finally flying how I would want I took it out today during lunch at it saw some wind gusts for the first time, and had some pretty bad tail wag issues when the wind came. After a little messing around I had it flying good and she had her first full battery flight. I was just taking it nice and slow, flying around a little back and forth, side to side, and some circles. my goal now for this one is not to crash Next I am going to get my v400 back working, and that will be the one i'll be a little more gutsy with since it's already been through a lot....

Here are the 2 things I messed with today that got rid of the tail wag:

One, I turned the tail delay on the 2702 all the way up, so my 4 potentiometer settings on the rx for my flybar heli are as follows:
Aile S. --> all the way down
Elv S. --> all the way down
Tail D. --> all the way up
Bal D. --> can't remember and i don't have my heli in front of me, but I think i turned it all the way up too (though this one might not matter if you have the Aile S and Elv S all the way down)

Doing the above improved my tail wag a lot, but there was still some of it going on when it got windy, so one more thing really made a difference. It has to do with the tail servo rod (the long one that goes along the boom from the tail servo to the tail rudder). First I made sure it was as straight as possible while routed to the tail. Second, and this is the real kicker, I tried to make sure it was secured as close to the blades as possible. I have the 450pro clone and on it there are 2 holders along the tail boom that hold the servo rod. I had put one up near the front, and the other kind of near the back. The one in the back was about 10cm from the blades, so i began to wonder if the rod was flexing when the wind hit the blades. I pushed the rear holder back so now it's only about 2cm from the blades, and now she flys pretty smooth I get maybe about 1mm of tail wag every now and then when hovering, but very very minimal and if i wasn't do damn picky i probably wouldn't even be able to tell (to get this perfect i'd probably need a more expensive heli ) I got a chance to burn through a whole battery, doing some basic flying, and it's nice to finally have a working bird
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Jul 28, 2011, 08:21 AM
kdean's Avatar
Hey dil.

Can you do a quick check of something for me? I'm not sure if my 2702v is doing what it is supposed to be doing. The elevator gyro is working fine, when i tilt the heli forward it tilts the swash backward and then back to level. But, when i tilt the heli to either side, there is no movement from the aileron and pitch servos. This would mean that only 2 of the 3 axis are working. Is this the same with yours? You may have to turn up your sens pots to get more movement. Thanks.
Jul 28, 2011, 09:20 AM
Human Being
Originally Posted by kdean
Hey dil.

Can you do a quick check of something for me? I'm not sure if my 2702v is doing what it is supposed to be doing. The elevator gyro is working fine, when i tilt the heli forward it tilts the swash backward and then back to level. But, when i tilt the heli to either side, there is no movement from the aileron and pitch servos. This would mean that only 2 of the 3 axis are working. Is this the same with yours? You may have to turn up your sens pots to get more movement. Thanks.
i'm not at home right now and don't have my heli with me, but I had been messing with those gyros so much that i'm pretty sure i remember this right (i can check later to be sure though). When I tilted the heli left and right the aileron and pitch servos were moving, and correcting the swashplate. When I had my gyros reversed, they didn't seem to be doing much even though the elevator still was, but once I fixed that they seemed to be pretty quick to respond to any tilt I made to the helicopter. Have you tried reversing the gyro? It's possible your rx is bad though.... To check your servos you could plug them into your v400 rx and tilt the v400 and see if they respond. Which heli do you have the 2702 in, is it your 450pro?
Jul 28, 2011, 10:16 AM
kdean's Avatar
Right now, i have the 2702 in my Tarot 450 pro frame (with Alfa 400, Volcano 40A esc, and Blue Arrow servos). I managed to scrap together the flybarless head, using one tarot blade grip and one exi blade grip. The tail is align with exi rotor blade grips. Its a real mess right now, but i've been putting alot of my heli money into the 500 project. I also have a new 2702v on the way but would like to test this fbl system on the 450 before i put it in the 500.
Jul 29, 2011, 02:37 PM
Human Being
any luck on that aileron gyro yet. I checked mine, and when i turn up the sensitivities, they move the swashplate the same as on my v400. I'm using exi213 servos which on my 400 i didn't have to turn the rx around like you did. Have you used the blue arrow servos on any of your other walkera rx's yet, and if so did you have to turn the rx around for them? I ask this because your rx on the 450pro is mounted the exact same way as mine, except in that picture you had your ail r and elv r switch opposite from me. I found that strange but attributed it to the servos being opposite or something, but now i'm wondering if it was just because you had your sensitivities pots all the way down so it didn't matter with the flybar.

As for an update on my v450pro, i've been having some good flights on it, and i'm getting more confident with it in the open area behind my house. It's flying pretty good, but there is still one thing i can't seem to get right. No matter how i good i adjust my pitch, I can't get the blades to track real well, tho the feathering shaft is new. I have noticed that on the main head that the blade holders and feathering shaft go into, it seems to want to rock back and forth. There is a bolt that goes through the head to hold it onto the main shaft, but it wants to pivot a little bit back and forth around that bolt. It looks like it doesn't have a really tight fit on there, so i'm thinking about taking it off and trying to bend it a little to tighten it, but i'm not too sure if that'd be a good idea.... maybe it's time to order my flybarless stuff instead
Jul 29, 2011, 05:22 PM
kdean's Avatar
I've read about that with the exi heads. After a crash, the head bottom hole might get bent open a bit, causing the head to rock on the shaft. You might have to take the head off and try to correct the bottom with pliers or a vice. It will temp fix but after a few flights you may have to correct again. That what i read have not experienced it.

Here is the thread I saw dealing with this issue:


Im sure now that the 2702v is not working. I've tried it on my v400 and same result. It might have happend in a crash but i did not notice because i was using the flybar head. I cant afford to try it with the fbl head.

I need to order some blade grips and a set of servos (hitec 5055) to get my other 450 pro frame in the air again. I still waiting on my other 2702v, spartan quark, and 2801 rx, to get here before i can finnish my 500 build.

I'm also working on using the 2612v rx on the fbl 450 pro, but found that it has to be mounted on the bottom of the frame. So, i need two servo extentions.

More waiting....

I think i'll take the M120 out and see how it handels a 10mph breeze.
Last edited by kdean; Jul 29, 2011 at 05:28 PM.
Jul 29, 2011, 08:16 PM
kdean's Avatar

450 pro FL w/26129 rx

Here are some pics of frankin-heli with the rx mounted below the frame. I'll post some video of flight later, if I can get it to fly.

This is the only way to get the gyro to correct in the right directions.

Depending on your tail servo normal operating rotation direction, you may have to reverse your tail servo arm. Putting the ball on the left of the servo.
Last edited by kdean; Jul 30, 2011 at 09:31 PM.
Jul 31, 2011, 11:56 AM
Registered User
Hi Guys, after reading your thread here ive noticed some of you have been having trouble with the 3-axis gyro's and I also read that you've been doing attempting to do airborne testing resulting in crash. I dont know whether this has been mentioned here but you can check your 3-axis gyro function by-

1. disconnecting your motor, then binding your heli
2. now increase throttle to around 50%
3. Check your ELEV gyro- tip your heli nose down and your swash should counter the movement(tilts back)
4. Check your AILE gyro next in the same way except with roll action.

If your using the 4F200 RX-2612 the orientation of the RX should be no different to the 4F200 in that its plugs forward and mount to the rear of the heli main shaft. The only reason some people invert the RX is if the gyro was giving the tail servo the reverse signal causing the heli to spin uncontrollably, but rather than invert the RX its easier in most cases just to swap the tail servo to the other side of the boom. The tail should hold well after that, if not check your GYRHLD>GYROSENS is set at about 78% for normal flight mode in your 2801TX.

Make sure your heli is vibration free as the RX-2612 does not behave well with vibration present. Its causes it to tip on take off. The later model RX that comes with the 4F200LM has reportedly fixed this problem from what ive read anyhow.

If youve fitted it to a belt drive clone then use a multimeter to test whether the boom is grounded to your motor mount. If the circuit is open then you should run a grounding wire between a screw in your boom and a screw in the motor mounting frame. Then check the circuit again with a meter. The belt drive can create static electricity within your boom and cause RX malfunction in flight.

Do all your mechanical setup with the RX dip switch in "ADJ" mode so the 3A gyro's dont mess up your setup resulting in servo's no recentreing. Then switch back to "WK" before flight test.

Ive got a RX-2612 fitted to my 4F200 and two more RX-2612's in 450's, and two RX-2610s, one in a HK450 and another in a HBK2. They all work OK if the setup is correct.

Hope this helps

Jul 31, 2011, 01:36 PM
Human Being
Hey Mick, thanks for the advice. I checked my tx settings (2801) and I had the gyrosens up pretty high so I just turned it down to 78. I had it flying pretty nice, but still had a little bit of tail wag present so this setting could help.

Unfortunately on about my 6th battery, I was lifting off and the helicopter foot got caught in the handles on this big box I use for my landing pad. It tipped a bit too much and the tail and main blades hit the box. I was able to get it corrected and back on its feet pretty quick, but since then the tail wag has gotten much worse. It may be the main gear, so i'm going to replace that and see how it goes. I also need to secure my rx better, so i'll be working on that today.

Oh, about the adj/wk switch, I have that on my 2614v rx, but not on the 2702v rx. Not sure why it's not on that one. When setting it up, I just try to keep it on as flat of a surface as possible.
Jul 31, 2011, 02:02 PM
kdean's Avatar
I found that with the 2612v rx, its better to check the gyro with the head spinning. So, i took off all blades and run a low throttle, then tilt the heli to make sure the gyro is moveing in the right directions. If i dont do this, its hard to tell what direction the aileron gyro is going.

Working with these walkera gyro / rx systems will vary from set-up to set-up. Servos, and servo placement, makes getting things right a strange balance of polarites. I found that the 2702v will work in the 500 if i swap the aileron and pitch servo connection. This is because the servo arms are in a position where it moves backward compared to the 450 set-up.

Im takeing the 2612v 450 pro out to the field later. Im very confident this time that everything is going in the right direction.
Jul 31, 2011, 02:07 PM
kdean's Avatar

im not sure but i think that when you enter set-up mode for swash (set sw), it should disable the gyro to allow mechanical set-up.

Not sure,

But i know in tail set-up, it will center the tail servo and disable head hold.
Jul 31, 2011, 05:56 PM
Registered User
Originally Posted by dilberto
Hey Mick, thanks for the advice. I checked my tx settings (2801) and I had the gyrosens up pretty high so I just turned it down to 78. I had it flying pretty nice, but still had a little bit of tail wag present so this setting could help.
Your gain may still be too high for that heli. Try reducing it a little at a time until the wag stops just like you would on an older style gyro. I had some problems with crazy tail wag on my HK450. At first I put it down to belt slip as the boom on the HK450 would slip into the main frame so I added some locking screws to the boom. It still wagged so I replaced the tail assembly with one from CopterX and still wag. So I set the gyro sens to 25 putting it in rate mode, and what do you know the tail held solid. Then I started fiddling with HH mode gyro settings until it held in HH hold mode. These days I do my mechanical setup with the TX programming "rate" mode for the gyro during setup and testing. Reverting to HH mode once im happy with setup after flight test.


ps- this video might be of interest-
Walkera 2801 Pro/Rx2702v setup for Trex 450/clone helicopters, plus test flight. (16 min 24 sec)
Last edited by Bravo47; Jul 31, 2011 at 07:13 PM. Reason: add link
Jul 31, 2011, 09:05 PM
Human Being
that sounds like you had a similar problem as mine, and i've been trying to get rid of it. You mentioned some things i'd like to try and i'll mess around with it some more once i get it back up and running...

I've been a little busy today. I turned down the gyrosens, replaced my main gear set with align gears, tightened the metal rotor head back into shape using visegrips, and secured my rx with a little block of wood (wood paneling 70's station wagon style ). I took it out back and it was flying mostly good but still had a little bit of tail wag. It wasn't enough to really bother me when flying, so I was taking it out and having some fun. About half way through my second full battery, I lost control of the tail and it went into a tail spin. I cut the throttle and steered it best I could into some real tall grass that I fly over (i mean real tall, over 6ft). Makes it a pain to retrieve the heli, but provides for a soft crash landing Haven't really dug into it yet to find out why I seemed to lose the tail that way, but I had noticed that there is a lot of play in the tail blades in general. When i wiggle the tail blades by hand, they goe back and forth between positive and negative pitch much more than i think it should. Being my only servo controlled tail heli, i don't have anything to compare to though.

Meanwhile, i've been doing some shopping for parts for my v400 and 450. I ordered the flybarless alzrc head for my 450, so hopefully that will help get things set up more similar to what the rx was engineered for. I'm also finally getting back to fixing my v400 and am getting ready to order a set of parts for that. I've been thinking about ordering another v400, but xheli has been out of stock for a while now...
Jul 31, 2011, 09:44 PM
kdean's Avatar
The looseness of your tail blade grips will cause tail wag. The tail rotor section of these 450s' really need attention before you go flying. My exi stock tail pitch slider was binding or sticking in full left and right. After takeing the it apart, i found that one of the arm joints was full of thread lock. I did not know any better, its my first 450 and tail servo control heli. I only noticied the problem after getting the Tarot frame and seeing how smooth and free that tail pitch traveled.

So, take it apart and find out what is causing the slop, and i'm sure that would fix your tail wag issues.

I took the mixed-up 450 pro w/2612v rx out and it flies. I was only able to put one battery through it because i did not track the blades, but also did not loc tight the ball link on the blade grip and it was comeing loose. There is also a thing the servos do, its like a pumping of the blades. You may get it if you bind your system, turn one of the blades sideways in the grip, and flick it with your finger. It wants to keep bouncing, and i noticed this was happening while flying a bit. I'll try to make some adjustments to the sensitivity and delay to work this out.

I also took my v400 #1 and its flying so smooth with the alpha at a low throttle setting. Also give better flight times for such a power hungry esc and motor.
Aug 01, 2011, 03:23 PM
Human Being
I'm putting in an order of a bunch of parts for my helis, and maybe i'll try to get some new tail pieces. The whole tail pitch slider seems to wiggle by hand a few millimeters back and forth real easy, until it catches. Maybe i'll look into some new links, or a new slider.

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