lama V4 foward fligth problem

[red350]

My lama v4 has the extreme upgrades alum. swash, extended iner shaft and the extreme body upgrade. also using dura blades with extended servo arms, linkage in 2nd hole. My question (or problem) is that in foward flight it starts off good then the heli starts to climb (after about 40 feet) and finaly ends up gust climbing with barely any foward movement. Is this normal or is there somthing that I can do to fix this? :confused:

[arbilab]

Because it won't operate outdoors (the wind is never calm here) I have never flown more than 7 feet in any direction, so I wouldn't have seen the problem you seem to have.

Empirically, the only way a V4 (I have one) can climb is with more throttle than needed to maintain altitude. Hypothetically, at extreme forward speed, it would bank as a result of advancing/retreating blades, but that should be well within the control range. What extreme forward speed does to the A rotor, again I can't say because I can't achieve extreme speed in any direction without hitting a wall.

Considering the blade airspeed vs. the craft airspeed, I can't see it causing a problem. But just because I can't see it doesn't mean it can't happen.

[red350]

Because it won't operate outdoors (the wind is never calm here) I have never flown more than 7 feet in any direction, so I wouldn't have seen the problem you seem to have.

Empirically, the only way a V4 (I have one) can climb is with more throttle than needed to maintain altitude. Hypothetically, at extreme forward speed, it would bank as a result of advancing/retreating blades, but that should be well within the control range. What extreme forward speed does to the A rotor, again I can't say because I can't achieve extreme speed in any direction without hitting a wall.

Considering the blade airspeed vs. the craft airspeed, I can't see it causing a problem. But just because I can't see it doesn't mean it can't happen.


I'm still kind of new to the heli thing. as you posted above, in regaurds to the throttle needed to maintain altitude. When I start forwards flight I feed in throttle to get the heli moving forward, once I get to speed should i reduce throttle instead of leaving it pushed up? This would make sense to me and could be my solution!!
I will try this the next time it stops raining and the weather clears up.

[abenn]

I'm still a beginner, so haven't done any significant forward flight. But I have been told that I'll need to throttle back a bit when I do get into forward flight because all helis get increased lift when moving.

[arbilab]

Yes, attitude changes require power changes. This is also true of fixed-wing craft (I'm a licensed FW pilot). But the power is only required for as long as it is a change in a model heli. More sudden change, more power. In a steady-state attitude, power = elevation.

[Mike_Then]

Understand that due to the inherent stability of a coaxial helicopter, you're never going to get extreme forward speed out of it. All coax helis are this way - even my Blade mCX which has the fastest FF out of all the coax helicopters I've owned (Hirobo XRB SR and Lama V4). Also remember that even for the Lama V4, there has to be NO wind whatsoever - even a gentle breeze has the potential to carry the heli away. It simply doesn't have the power or the capability to fight any sort of wind. Is it absolutely dead calm when you fly it outside?

It has something to do with the way the swashplate is aligned in a coax heli. Once is starts to slow down in FF, try flying a somewhat "serpentine" pattern. It does something to the way the swashplate is aligned (I don't fully understand it myself so maybe someone else can chime in and clarify) and it helps to maintain a reasonably fast FF. That's what I do with my Blade mCX and it really scoots.

[Balr14]

The upper rotor wants to stabilize the heli; the lower rotor wants to cause movement. The upper rotor will catch up and win, sooner rather than later. Constant direction change prevents the upper rotor from catching up. A shorter flybar or less flybar weight removes some of the upper rotors authority.

[jackclarke]

Taken from the Wikipedia -

"A coaxial model helicopter has limited forward speed, especially outdoors. Most such models are fixed-pitch, i.e., the blades do not rotate on their axes which simplifies the model, but eliminates the ability to compensate with collective input. Compensating for even the slightest breeze causes the model to climb rather than to fly forward even with full application of cyclic."

[Lamedico]

In other words coax copters are designed for calm conditions and slow flight. If you want a chopper that can fight wind and zip around you don't buy a coax.

[robinluijk]

If you want to fly forward with a LAMA4 then do it inside! Any slight air movement outside and you struggle, even with full forward cyclic. Still fun though!

For my second heli I bought the Honeybee FP (E004). :)

[arbilab]

Small world, my second heli after V4 was HBFP too. I need MUCH more airspace! While I can toss the V4 around a 7x11 room without consequence, the HB WILL hit something in the time it takes to error and respond to correction.

[jackclarke]

Small world, my second heli after V4 was HBFP too. I need MUCH more airspace! While I can toss the V4 around a 7x11 room without consequence, the HB WILL hit something in the time it takes to error and respond to correction.

In most cases "trying" to correct and it already hit the wall and in more pieces than you started. Have you tried collective pitch? The 450's are still pretty skitterish - its the nature of the beast - but they can be tamed to behave in a smaller room if you hold their leash tight enough. Choke chains work best.