I've got issues with my new tarot head

[HRPuffnstuff]

I've been having a vibration that mainly shows up in IU when the head speed picks up. It's causing a vibration throughout the heli. At first I thought it was being caused by my tail boom having slid up but fixed that issue and same problem. I checked the blade grips which were a bit loose and rebalanced the blades still there. Now I recheck the head and the blade grips have a lot of slop in them that I can't seem to get out. I compared it to the other head I've got and it's rock solid where this one is sloppy with the grips. I'm thinking about swapping out the feathering shaft to see if perhaps this one is defective. I loctited everything down in the beginning but this is strange.

Anyway I just swapped heads so the good one is now installed. I also noticed that the new main shaft that I'd used to build the other head is warped. I'm going to talk to hh about that one since one is straight and the one I used, without checking I might add, is not. Guess I'll fiddle with this head a bit and see if a new feathering shaft straightens her up.

[HRPuffnstuff]

Ok disassembled the head, oiled the bearings, reassembled and it seems to be tight again. I'm going to put this head in the box and use the other one for now. Not quite sure what happened unless the permatex didn't cure.

[shreddedpaper]

I had the same problem, whole heli shaking in IU, usually stopped as the head speed bled off when the battery started to drain. Drove me nuts trying different gain settings trying to solve it.
Problem was 4 little screws in the washout bearing connection. They WERE installed with loctite, but they still came loose. When I found they were loose, one was actually gone, other three in by about a thread or two.
I have since started using the brand name "Loctite" and not the "Permatex" brand. It does hold much better and the shakes are gone.

[HRPuffnstuff]

I'm glad you mentioned the wash out arms because I'm checking mine now and they are loose. I meant to check them in the beginning but it slipped my fragile mind.

[Gregchico]

At least you did not break your bolt....

[Being]

Originally Posted by Gregchico

At least you did not break your bolt....

Get rid of those brass washers. They are too large in diameter and ride on the bearing shield and don't allow the bearings free movement. The bolt head is the right size to touch just the inner race. Since removing them I'm able to tighten the bolts as much as I want and still have free movement.

[shreddedpaper]

Originally Posted by Gregchico

At least you did not break your bolt....

Oh Snap!

did you get the piece out?

[Gregchico]

I still have not got he broken part of the screw out, it is lock-tited in really well (I did not want it to come out.....)

This head was on my backup 450 that I just converted yesterday and had a"shake" like the OP talked about. So I checked mine and look what I found. My original FBL head/conversion 450 is still fantastic with 20-ish flights on it and one minor crash (that would have needed a new flybar).

I ordered a second head anyway when I ordered this last conversion kit (because I'm impatient and hate waiting for the mail) so I switched heads so I'm back up and running so to speak. I ordered 2 "Tarot 450 Pro Flybarless Metal Main Rotor Housing Set TL45117" from OOModels so they are on the slow boat over and I can have a backup ready to go again.

[InFocus]

Originally Posted by shreddedpaper

I had the same problem, whole heli shaking in IU, usually stopped as the head speed bled off when the battery started to drain. Drove me nuts trying different gain settings trying to solve it.
Problem was 4 little screws in the washout bearing connection. They WERE installed with loctite, but they still came loose. When I found they were loose, one was actually gone, other three in by about a thread or two.
I have since started using the brand name "Loctite" and not the "Permatex" brand. It does hold much better and the shakes are gone.

Something else that I noticed in this picture, and I've posted about this before.

The phase angle on these heads is not at 90degrees. For example, notice in the pic the swash ball is exactly forward, lined up with the elevator ball.
With the swash ball in that position, the blades should be exactly 90degrees perpendicular with the heli. Also, the ball on this grip should be directly above the swash ball.
You can see that the grip ball and thus blades, are lagging behind just a bit.

I can think of 3 reason why you really want the phase angle at 90degrees:

a. When you command an elevator change, if the phase angle is no 90degrees, you'll also get just a slight amount of aileron change.

b. I think this could cause the FBL to have to chase the heli a bit, because as it tries to make an elevator correction for example, the heli may also get a bit of aileron change, which the FBL will try to correct that, and so on..

c. This is also important when your checking your cyclic deflection angles, as you normally check the elevator deflection angle with the blades straight across, and the aileron deflection angle with the blades parallel with the boom. If the phasing is not exactly 90degrees, then you won't be at the true max deflection.

The correction for this is pretty simple. Just remove the washout arms and flip them over, i.e., the word Tarot will be upside-down, facing inward. You have to unmount/remount the links as well. This puts the 'wide' part of the arm against the headblock. The end result is the swash phase angle is exactly 90degrees now.

To be honest, it is is only off by a really small amount, so maybe you won't even notice, but I wanted the best physical setup possible. (on edit: also if you look at pics of the Blade 450X, you can see its phase angle is exactly 90 degrees).

[shreddedpaper]

I wouldn't put too much stock in that pic, blades are folded back and the swash is crooked.
My washout arms are at 90 at midstick. I've seen the arms reversed before and they really stick out at an odd angle.

Maybe I'm misunderstanding what you're saying? I've never noticed any strange effects from this, stick forward-heli forward, stick left-heli left and so on.

[spykez]

Some of these pix are also done on cameras that have quite a bit of ... what do you photographers call... spherical aberration barrel distortion etc...God knows my mobile phone's camera is pretty bad in that regard.

[Coorslite]

removed the brass spacer, snugged everything up tight and still have a vibe at 100% headspeed...any other ideas?

[InFocus]

I'm not talking about the washout arms being 90 degrees..

Phase angle is. Looking down from the top of the helicopter..

If the blades are exactly at 3 o'clock and 9 o'clock, the swash balls for the blades should be at exactly 12 o'clock and 6 o'clock.. That would be a 90 degree phase angle..

I know what folks mean about cameras playing tricks, but that is not the case here.

Check for yourselves on your heli, and you'll see what I'm talking about.

[Gregchico]

Originally Posted by Coorslite

removed the brass spacer, snugged everything up tight and still have a vibe at 100% headspeed...any other ideas?

If the vibes are in the air try turning down your pitch and/or roll gain. Mine was at 40, now it is vibe free at 32.

[shreddedpaper]

Originally Posted by InFocus

I'm not talking about the washout arms being 90 degrees..

Phase angle is. Looking down from the top of the helicopter..

If the blades are exactly at 3 o'clock and 9 o'clock, the swash balls for the blades should be at exactly 12 o'clock and 6 o'clock.. That would be a 90 degree phase angle..

I know what folks mean about cameras playing tricks, but that is not the case here.

Check for yourselves on your heli, and you'll see what I'm talking about.

You're right. It's off by just ever so little on the B450. I had never noticed it before.
It might be the slightly smaller diameter of the swash compared to the Trex type. I have the same head on both machines, the Trex appears to be near perfect and has more vertical washout arm at center stick, the B450 is just slightly off and the arms toe in at center stick

I have a spare rex swash, I may play around and see if a pin can be located/drilled and pressed in to the plate and function on the B450. Good eye InFocus, never noticed.

[InFocus]

I agree with what you've said though, if what you have is flying fine, then there's no issue, its just a nit thing. My trick to flip the arms over solves the issue though, so you don't have to do the advanced stuff like trying to put a Trex swash on the B450.

[shreddedpaper]

How are you flipping the arms over? do you have a pic?

[InFocus]

Note how the wide/thick end of the arm is away from the head block, to sort of act like a shim. (I have the grip links removed so they don't get in the way of the picture.).

[spykez]

Originally Posted by InFocus

I'm not talking about the washout arms being 90 degrees..

Phase angle is. Looking down from the top of the helicopter..

If the blades are exactly at 3 o'clock and 9 o'clock, the swash balls for the blades should be at exactly 12 o'clock and 6 o'clock.. That would be a 90 degree phase angle..

I know what folks mean about cameras playing tricks, but that is not the case here.

Check for yourselves on your heli, and you'll see what I'm talking about.

I got an old head and had to manually adjust mine. So it is spot on but a right PITA to get right. Separate washout base follower arms. I have just seen perspective distorted on some pics so I usually take angles I see on pictures posted sometimes with a pinch of salt.

But you're absolutely right. Try and get phasing right.

[shreddedpaper]

Thanks for the pic InFocus, that explained it well. Out of curiosity, doesn't your washout arm collar rotate on the base of the head itself? Could this be rotated to correct the phasing? or does that cause another problem? Sorry if I'm beating a dead horse. I have the blockier looking head, and after looking at it, doing what you did would most likely correct the phasing. But as I said, the phasing is only out by maybe 1mm. On my next rebuild, I will try it to see if there are any noticeable differences.