Knight 3D phasing question

[TheBum]

I noticed when I was re-setting the phasing on my K3D that there's a bit of slop in the phasing ring slots. When aligning the head and affixing the phasing ring, should the slop be cheated assuming that the phasing ring is always "pulling" the phasing pins?

[Mercuriell]

I assume you mean the slots in the washout block - I think it is a fair thing to do to rotate the ring forward just a tad to take up slack as I have found even ~0.5mm can make a difference to mixing - having it set square on is very nearly right but maybe just 0.5mm advancement ~ 6° gets it pretty near spot on for my setup - I plan to do a quick video on setting up the phasing ring as it is unusual in present day helis but not at all difficult to do

[TheBum]

Originally Posted by Mercuriell

I assume you mean the slots in the washout block

On the Knight, the slots are in the phasing ring and the pins are attached to the washout block.

The reason I'm kind of paranoid is because I was having problems with the heli rolling during power loops, which sometimes cause the exit to the loop to be at probably 60 degrees to the entrance. It may have been me, but even when I was cognizant of my stick positions, I was having the loop problems. Part of the problem is that the phasing may have gotten messed up during a botched auto that resulted in a boom strike. A dent in the boom was the only evident damage, but maybe the phasing ring slipped too.

[Mercuriell]

- same as the Odin ! - getting too old to try and mentally visualise stuff ! Anyway same comments apply

[hornet dave]

Regarding the phasing block, my experience with several helis has been that 90 degrees is close but never the best setting.

Here's my trimming technique:

1) level the swash with a swash leveler.
2) balance the heli on the mainshaft. Do NOT lift the heli by the flybar and say "it's balanced!", as that tells you nothing worthwhile. With about half a tank of gas, grab each blade grip and lift the heli so that it is on its side, with the main shaft parallel to the ground. Either the nose or tail will fall to the ground, play around with some weights until it stays parallel. If it takes less than an ounce of weight on the nose, or 1/4 ounce of weight on the tail, I would say you're OK.

the purpose of 1&2 is to get the heli to trim correctly with a level swashplate. if you end up having to add 14 clicks of trim one way or another, the rolling behavior of your heli will suck regardless of what you do with the phasing ring, and you will be seriously out of trim when you fly inverted.

3) Check your phasing - get it set close to where you think it should be and go fly. Rolls to the left and the right (without any elevator correction) should be without any significant nose-up or nose-down attitude after the maneuver. If the phasing is off, after a roll one direction, the nose will be up, while rolling in the other direction will cause the nose to go down. A couple continuous forward and backflips, without aileron correction, will also show you a phasing error. After doing a couple forward flips, the model will tend to have rolled in one direction, while backward flips will cause it to have rolled in the opposite direction. That's a phasing issue.

4) If you have phasing issues, adjust the phasing ring slightly, one way or another by a millimeter or so and try it again. You will either make the phasing better or worse, so try the flying tests and adjust it from there.

Switching blades, dampeners, paddles, flybar weights, these things may require a change to your phasing, so its a good thing its adjustable.

[webstep1]

but maybe just 0.5mm advancement ~ 6° gets it pretty near spot on for my setup

Same here - I have the timing advanced slightly.

[Ah Clem]

Alan,

There should be very little slop in the phasing ring/pins. Wear due to crash damage, lack of lubrication, or dirt/grit grinding/wearing is usually the culprit here.

I too have the timing advanced on my Knight 3D and Knight Pro (as others have mentioned).

I agree completely with the method Hornet Dave described.

After flying/testing/adjusting/repeating, the phasing is in a similar position on both .50 sized birds as it is stock on the Atom.

[TheBum]

Originally Posted by Ah Clem

There should be very little slop in the phasing ring/pins. Wear due to crash damage, lack of lubrication, or dirt/grit grinding/wearing is usually the culprit here.

I've only flown it for a few weeks and crashed it once, and it hit the ground at a very shallow angle even then. I can't believe that one crash would cause the phasing ring slots to spread that much. The question is: How much slop is "very little"? It's maybe +/- 1 degree at most.

I agree completely with the method Hornet Dave described.

I don't think my control is fine enough to tell the difference between phasing and inadvertent stick input.

[Ah Clem]

I would not think so sir.

Is it much different than when brand new?

[TheBum]

Originally Posted by Ah Clem

I would not think so sir.

Is it much different than when brand new?

Not sure. I didn't pay that much attention to it when I first set it up and only noticed it because the heli was rolling on me during loops and so I started paying close attention to the phasing. As I said, the phasing might have gotten jolted out of position after the botched auto for all I know.

[Ah Clem]

How far does it move?

I would try the method outlined above, as exact 90 degree phasing is seldom correct anyway. It is sort of the default in terms of getting it generally right.

The Knight 3D should fly through a loop with very little in the way of correction. It should perform an axial roll with very little in the way of correction-mine did not, until I played with the phasing.

[TheBum]

Does "advancing the phasing" mean setting the flybar such that it's offset clockwise from the boom when the swash balls are aligned?

[Ah Clem]

Look at your Atom.

The phasing/timing is advanced on the Atom.

The head is ahead (no pun intended) of the swashplate.

[Mercuriell]

Originally Posted by TheBum

Does "advancing the phasing" mean setting the flybar such that it's offset clockwise from the boom when the swash balls are aligned?

It's setting the blades forward a bit so that when they lag backward during rotation their centre of thrust is perpendicular to the mast - this is achieved by rotating the inner ring clockwise on the outer ring of the swash - there's a nice little discussion of blade lag on the compass site

[TheBum]

Originally Posted by Mercuriell

It's setting the blades forward a bit so that when they lag backward during rotation their centre of thrust is perpendicular to the mast - this is achieved by rotating the inner ring clockwise on the outer ring of the swash - there's a nice little discussion of blade lag on the compass site

I already read that back when I was researching my Atom 500 purchase and a certain element was complaining about phasing errors.