bugsiegel

My Feedback: (2)

I have a questio about a governor. I'm new to heli's and have read all the threads about heli governors and I still have some basic questions. because of the cold weather I haven't been around the local guys to ask these questions so I'll ask them here.
I understand that a governor will hold a spacific rpm especially when unloading and will help avoid overreving at low to 0 thrust or even negitive thrust. does the governor lock the throttle to a spacific rpm or do the rpm's change with the movement of the stick and still protect the engine from drastic rpm changes.
and the second part of this queston is this. can't the heli just be throttle locked to a desired rpm and then just flown on pitch? I'm refering to the two other modes not normal mode.
Paul

wisdom-seeker

You have to understand that without a governor, the engine will change RPM if the throttle is not adjusted to compensate for changes in torque load. This is normally done with throttle/pitch curves in the radio, which attempts to keep engine RPM constant by varying the throttle as the pitch changes. There is no feedback in that system, and as a result, RPM can change as a result of changing forces, especially in hard 3D flying. A governor, directly senses engine RPM, and changes the throttle as necessary (independent of stick position) to keep the RPM constant. In that case, the throttle input from the transmitter is used as a suggestion, not a mandate for throttle position.

sandal

Without a governor, the collective stick controls rotor pitch, and throttle is mixed in via the throttle curves.

The governor replaces the throttle curves. You can program rpm settings for normal and idle-up modes, and the governor will keep rpms constant. That is the governor's job; keeping rotor speed constant at all times during all sorts of maneuvres. The throttle servo is plugged directly into the governor and not the receiver, and the governor takes control over the servo to keep rpms constant.

Can the heli be throttle locked? No. The need for power is not constant. Lets say you're flying in idle-up 2 and the collective stick is at 1/4. This can be at least two very different situations:
1) You are in a high speed dive. Very little or no power is required, and the governor will pull the throttle back to idle to prevent the rotor from overspeeding.
2) You are hovering inverted. A lot of power is required, and the governor will increase throttle to keep rpms at the programmed value.

Cyclic inputs require more power, tail rotor input to the left require less, to the right requires more.

Without the governor, you have to go for "average" settings that will be approximately correct, but never perfect. Humidity and temperature will make settings drift, and the heli will fly slightly differently every day. The governor makes revo mixing and throttle curves unnecessary (but keep the throttle curves programmed in case the governor quits). It keeps rpms constant no matter the weather or maneuvres (within reasonable limits).

I hope you got answers to a couple of your questions. Someone with more heli experience can give you more information. I'm going to order a GV-1 as soon as possible.