evo 90 head

[Hassan]

I have a hirobo x-spec, Can I convert the head to a evo 90 head? Will it make a difference? If yes...where can I get the evo head set? Thank you

[Laurens]

In the US there was a promotion that you could buy an Xspec with Evo head. So I know its compatible with the Xspec. I think It'll make a difference otherwise they won't design a new head :wink:

[Jafa]

You can get more cyclic out of the Evo head than the Plastic and XSpec heads
It's about 7 degrees versus 6.5 at best (6 degrees is common on a Freya)

MrNoodles runs a Evo head on a XSpec - he likes it

But I must say, I've grip flipped my plastic Freya and the cyclic is quick
Certainly quicker than a Sceadu and quicker than a Evo I believe
I have just over 8 degrees of aileron
and just over 7 degrees of elevator
The difference is due to backing off to avoid binding
The head was not designed for these extremes

If you are interested I'll post more info on the grip flip

[Hassan]

Thanks for the help guys, yeah Jafa please tell me more about it.

[Jafa]

Ok - here's what you need to do for the grip flip.

1) Disconnect the grips and flip them over
(Taking blades off is a bit of pain with the bolts upside down)

2) You will now notice that the bell mixer on the seasaw
is on the wrong side - you need to flip the mixer to the other side.
But, it's important that you use the seasaw side with two screw holes
for the bell mixer, if that side is already there then you are fine.
Means you were using the middle position, the single hold side.
If you were previously using the two hole side you will have to flip the seasaw over
Mount the bell mixer on the seasaw hole furthest away from the mainshaft.
This is the stability setting and is need to prevent bogging and provide
smoother control (the grip flip makes the head quicker and more agressive)

3) The swash has two short and two longer balls,
use 4 longer balls instead - gives a mild increase in cyclic

4) The link from the swash to the bell mixer goes into the hole closest
to the bell mixer mounting bold

5) The link from the bell mixer to the grip goes in the hole furthest
from the bell mixer mounting bold

6) You need a double ball link in the grip - use the outside ball
Both M/A and Carbon extreme make double ball links,
I used CX ones cos I had them and also used one washer under it
(This step is important - it's about the delta offset and is needed)

7) Use the outter holes on the radius arms to the flybar cage

8) Reverse your pitch servo, the swash now goes up for negative

9) You will now fine that you can get something like + and - 14 or 15 degrees
of collective - way too much, bog city - Peg that back to 10 or 11

9) Check for binding with full negative (swash at the top)
and full forward elevator (both at full at the same tiime)
The swash tends to hit the rear radius pin

That's about it - hope I got it all

Make sure your engine is well tuned,
get a solid head speed just above the peek power rpm of the engine
and run a somewhat agressive throttle curve (lift the mid point)

I have only recently done this to my Freya
and I am rather taken with how fast she rolls
But it has not lost any of the Freya flying finess

Augusto, I3DM and others have all done this in the past
These steps are a composition of their experiences

Good luck...

[Hassan]

Thank you very much Jafa, I will try that and let u know what happens. I really appreciate it.

[Jafa]

No problem at all - I'm sure you will enjoy the results

It will be interesting to compare notes with you
on our flying impression of the Freya with this modification