Logo 600 stretchers (to 700) consider this.

[MrMel]

I was out flying back to back with my stratus, switching heads between Logo 600 head, L14 hardned shaft with stiff dampners and original stratus head with solid shaft.

To put it in plain text, the heli when I had the Logo head flew like crap.

The whole mast + head is too soft for 700mm blades so in manuouvers like piroflips etc it start to "wobble", like if your timing is behind, before, behind, before and so on.

Worth considering, If I gonna go 700mm on my Logo, I will put on a stiffer head/main mast.

[Flybar-less]

I run 2 washers per side from the 3092 kit on the stock head. Seems stiff enough.

[MrMel]

I was running K&B greens + Mikado hardest, Im talking about whole head moving, shaft flexing...

[Eyon]

im supprised if it does, its a pretty decent head block. i run orange k+b with a hardest mikado, and the plastic rings, and i cannot get any flex at all in the head! works great with V-Extremes and V-Bar

[MrMel]

Well, I wont be running logo head on my future stretch logos at least.

Just wanted to give a heads up, maybe its as simple as this is why some feel it fly strange...

However, on the bench, measuring how much force is needed to bend the blades down to a potenial blade strike, you can actually see the shaft flexing, not only the dampners.

[Eyon]

i have a feeling that they fly strange due to low disk loading. there is always a very fine line with loading. too much it will fly like a HOS, too little then you loose any precision and all momentum through maneuvers. a decent 90 size i think will work out between 9.5-10.5lbs, but when yuou go for a 7.5lb model on 710 blades, you will have no massive directional stability.

its like the same with planes, too much, its a pig to fly, too little its a pig to go in a strait line, get it right, then it flies beautifully.

might be worth experimenting and putting the weight of the logo up to 9lbs with the stretch kit, then see what happens!!

[MrMel]

perhaps is it because its so light you wont see the flex I did today.

(it was very profound, piroflips really looked like crap)

[Griffo]

Hmm this problem sounds very much like the one I experienced whilst using the 700 for filming. Very interesting. I had assumed it was the stiff neoprene belt that was casuing this so I purchased a couple of new PU belts to replace it (not installed yet).

I've got a pack of K&B dampners so I might try installing the green ones. Perhaps that might fix the problem.

[Flybar-less]

My 700 weighs about 8lbs. with the FP 5350s. It flys very precise and predictably wtih 690s or 700s. Rolls ,piro-flips, funnels...all manuvers are very precise..

I am running 2,200 headspeed. Perhaps this helps.

I have used Maniac 700s (200g), Radix 690s (190g), and RT 690s (170g) with similar results. The 2 motors have been the Neu 1915/1Y w/14T, and the Actro 32-3 Max w/18T.
The Actro allows about a minute more run time and cooller batteries.

[MrMel]

I would worry running 2200 with 700's on ANY plastic grip, I would worry ALOT.

[Flybar-less]

I just replaced them on this heli becuse they had about 400 flights with Maniac 620s @ 2,400 RPM.

[MrMel]

Your running undersized head with RPM's not even supported by the blade manufacturer, I would be afraid, but thats me.

Ive gone the opposite way, lowering headspeed, raising pitch, flying smooth.
Got 6+ min flighttime now on many of my machines :)

[Flybar-less]

Since my first heli in 1976, a Revolution 40, a Cricket in 1982, many XCells in the '90s, I've owned and flown much worse. And yes, recently the famed Align 600 blades that I would not fly due to departing weights.

The Head on the Mikado is built better then the FAI heli I competed with 16 years ago, which ran NHP 210g 720s @ 2,200 RPM. Intrestingly the only engine that would power this beast was a supercharged YS91 4 stroke. Bent lots of connecting rods.