tarot zyx bad problem. please help

[hemp]

Originally Posted by Mikej

I would look into 2 areas - vibration and static build up.

I have good news and I have bad news.

The good news is, I believe I've identified the problem and resolved it (waiting for rain to clear so I can get final confirmation.)

The bad news is, I have to eat some crow and admit to being wrong - I really don't like being wrong.

I said several times that I was pretty sure A) it wasn't caused by vibration and B) it wasn't the tail. Appears I was flat wrong on both counts.

I still don't quite understand the sequence of events, but in any case, I pulled the tail belt off and spun up the motor and the issue went away - so I had isolated the problem to being related to the tail. Pulled apart the tail assembly and went through every component, only to discover that the feathering shaft had a slight bend. It must have happened in the crash that followed the first crazy vibe incident preceding the rebuild. I did check over the tail when I rebuilt, but obviously missed this bit.

The design of the B450 feathering shaft makes it hard to "test" for a bend, so instead I measured for it. In hindsight I probably checked it the first time by spinning the screw on one end and watching the grip on the other end - that trick doesn't work with this bird because the shaft doesn't run through the hub, it's all one solid piece:


Thanks to everyone who offered help and suggestions, will be nice to finally be airborn again. Hoping the rain clears soon.

[Mikej]

Excellent - let us know how it goes ..

[4 stroke flyer]

Rain and gail force winds finally backed off. I took it out and got in a few mins of hover. All seems well and no tip over at take off. Thanks for the help

[BlueRay]

Originally Posted by 4 stroke flyer

I installed the ZYX on a trex 600E. Went threw the set up a few times just to make sure things were right. I got the machine lite on the skids and it just flipped on its side so fast I was amazed. Has anyone had or herd of anything like this with this unit? Any help would be great. Thanks
This is not my first flybarless unit. I curently have a BeastX and a Skookum 720.

Hi 4 stroke flyer, for what its worth I have had an occurance a couple of times where the heli has tipped on its side, suddenly on takeoff, the takeoffs where soft and slow so I managed to kill the thrittle and it righted itself back on the skids costing me only a set of blades a couple times, (the DFC head seems tough), I have checked all componants and set up paramiters and everything seems fine and the heli has performed fine many times since.

I'm not sure I have my tail pitch offset quite near the recomended 8 deg because I do often get a fair bit of rotation on startup and have to rotate the heli on the deck to get my normal tail-in orientation back before take off, I'm not sure but I think the tipping could have been because the skids got caught up on a rough part of the concrete and the heli could not rotate so it tiped to one side, since I made this asumption I am more agressive on startup / lift off and have not had a problem

Just my 2 cents, hope this is not a fault of the gyro..............

Tarot 450 Pro V2
Tarot DFC
Tarot ZYX
newbie pilot

[hemp]

Originally Posted by Mikej

Excellent - let us know how it goes ..

It's going. I flew four packs today, no hard landings.

It's clear I still have a vibration issue (even after replacing the bent tail rotor hub.) Pretty much has to be somewhere in the tail. However, I turned down the pitch & roll gains to 18 and it flies through the vibes just fine. I know, I'm tempting fate but I've sunk so much money and time into it already; I just need to fly so I don't lose my mind. Fixing it will come later, one way or the other.

[clough42]

Originally Posted by hemp

The design of the B450 feathering shaft makes it hard to "test" for a bend, so instead I measured for it. In hindsight I probably checked it the first time by spinning the screw on one end and watching the grip on the other end - that trick doesn't work with this bird because the shaft doesn't run through the hub, it's all one solid piece:

Most tail hubs are like this, but there's an easy trick to check for a bent hub. Pop the links off the grips, loosen the setscrew and take the hub-grip-blade assembly off the heli. Fold the blades together so the tips overlap. Pinch the tips together with the thumb and index finger of one hand and spin the hub with the other. If it's bent, the blade tips will shift and you will feel it.

[hemp]

Originally Posted by clough42

Most tail hubs are like this, but there's an easy trick to check for a bent hub. Pop the links off the grips, loosen the setscrew and take the hub-grip-blade assembly off the heli. Fold the blades together so the tips overlap. Pinch the tips together with the thumb and index finger of one hand and spin the hub with the other. If it's bent, the blade tips will shift and you will feel it.

Thanks for the tip! I'll give that a shot next time I'm wondering...