5 Blade head phasing

[RotorBlade]

Guys
I'm cracking on with my Trex 450 pro build for an MD500 and want to get the 5 blade head set up right.
I watched a video on how to phase it, but the swash follower (is that what it's called?) with which I adjust the links to get to 90degs, attaches to the shaft via a collar with a hex bolt through it, a bit like the jesus bolt above it. This bolt screws into a small threaded brass collar which has no flanges, so there is nothing to grip to enable the hex bolt to be tightened to lock the collar round the shaft. You can see what I mean in this picture - the small round brass bit just visible below the head.

Is that a fault with the head? It was not expensive, so is it useless? What about a longer bolt with a nut?
Thanks for any help fellas.
Keith

[trillian]

It may just be me at the end of a long day etc. but I cannot make out from those pics exactly what it looks like. Basically there has to be a swash driver that attaches either to the hub or the shaft and has a jointed arm going to the swash.

[Aidi]

Cant see it on the pictures, but you are right about the swash follower. Once in the correct phase it need to be tighted up so it does not move on the main shaft.

Be careful when setting the phase on a multiblade head. Where you might read that links from the swash to the head need to be at 90 degrees, you will more than likely find the the actual phasing is well out of kilter. You can only really get around this if you are going to use electronic phasing (3 axis flybarless controller).

To get true phasing on a 5 blade head, what you need to do is line 1 of the blades so its parrallel to the tail boom. Then whilst stirring the cyclic, move the swash follower until you get on movement on the blade which is over the tailboom. As said, you might find the links to the head are not parallel, but thats not too much of a problem if the angle is not to acute.

Something also to bear in mind is the quality of the plastic links. The one i bought was pretty good from a metal point of view, but the plastic links were an awful fit onto the balls. Cost me about £4 to get a good quality set of plastic ball links to do the job properly.

[RotorBlade]

Yeah, sorry - I didn't mean to load the first picture.
Also, I took them to email to a mate to show the problem I have with the length of the elevator arm detaching from the anti-rotation bracket because it is too short, because the swash is a different size to the original.
It showed the bit I meant so I decided to attach it.

I've cropped a bit out of it now to show what I mean. The little brass round is all there is to tighten the bolt that secures the collar round the shaft and it's that collar that adjusts the hinged section setting the phasing. If I tighten the hex from the other side, it just rotates. If I try to grip it with pliers, there's virtually nothing to get hold of. It can't be left, yet if you look at the 4 & 5 blade heads availabe, they all look the same.
Thanks
Keith

[RotorBlade]

Thanks Aidi - I will be using an Align 3G. What's the best way t get it right with that?
Keith

[Aidi]

No idea mate! I built and flew mine without any stablization! Its possible, but i wouldnt advise it if you have the 3G system. I cant remember the websites, but there are some dedicated scale heli forums out there which i am sure will have lots of info on this.

Just incase you get confused about my description with phasing and some of the videos on the net. You can achieve the same result with phasing by using a blade at right angles to the boom and the link from that blade grip at an angle to it is then in line with the boom. It achieves the same result as the boom method.

The only other thing, and it might be more to do with me trying to fly without stabliization, is tail authority. I found with mine i had to fly carefully or the tail would blow out very quickly and suddenly! But i think this would more than likely be counter acted by using the 3G system.

[Zeeflyboy]

Tail misbehaviour is much more likely as a result of the lower headspeed used with multi blade heads...

You either need to use a multi blade tail or longer blades etc.... Something to increase the authority at lower speeds.

[Aidi]

Yep, go high and it was almost uncontrolable, go low and it will hold, but not well. I figured a four blade tail would be better or as you said a longer blades. Perhaps gearing would have also been an option. I sold it before i smashed it!

[RotorBlade]

I've got a 4 blade tail on the way from the US;-)
This mooma is gonna FLY

Mind you, I've got to resolve this swash follower first.

[trillian]

I've got a 4 blade tail on the way from the US;-)
This mooma is gonna FLY

Mind you, I've got to resolve this swash follower first.

Worst case if the supplied swash driver isn't getting the phasing right I would imagine you can get another one that clamps to the main shaft and can be positioned where you need it.

[mole hunter]

Hi RB,

I can't quite see your problem with the top clamp bolt from your photo. Has its thread stripped or has the the socket rounded out?

Anyway, here's a bit from our dan on the subject. Multi blade Phasing video - Heliguy.com

He had a 4 blade tail rotor as I remember and it flew really well.

Good luck, Marty

[RotorBlade]

Hi Marty - the thread is good from what I can tell, but the way it was assembled, the brass (I don't know what to call it) you can see receives the hex bolt that tightens the clamp. The hole in the assembly is round - the brass bit is round. As I tighten the hex bolt, the brass bit simply rotates in the collar and I cannot tighten it. It is so small and less than 1mm proud of the collar, so I cannot get a pair of pliers on it to hold it in place. It is similar to the jesus bolt idea, except that with that, the bolt sticks right through, you put a nut on it and tighten it down.
Unless I can tighten it, the swash follower will never hold the phasing in place.
Hope this explains it better.
Keith

[dannyhough]

Longer bolt with a Nyloc on it and problem solved, i take it you can remove the brass thingy???

[RotorBlade]

Nah - you need the brass collar to press down on the inner section, locking it to the shaft, while allowing the outer sleeve that links to the swash the freedom to move. Longer bolt worked though!