question about idle up1

[Matt]

is this true about the head speed i thought that it had to be a v like 90 85 80 85 90 not 90 90 90 90 90
Recommended headspeeds

Headspeed
CP micro heli 2000-2400 rpm
ECO 8 1400-1800 rpm
Other CP nonmicro heli 1600-2000 rpm

If you are a beginner, then use a headspeed at the lower end of the range. If you are experienced, then use a headspeed at the upper end of the range.

Third, immobilize your heli so it will not fly by weighting it. For a micro heli, you can put a small ruler on top of the skids and weigh down the ruler with bricks on both ends. For a nonmicro, you can use a larger piece of wood and cinder blocks. Be sure to use a heavy weight on both ends. Make sure your landing skids will not separate from the helicopter frame.

Fourth, select the two-blade propeller mode on the tachometer. Next, place the tachometer underneath the helicopter so the sensor points upward and the rotor blades will pass over the sensor. Make sure the flybar and flybar paddles do not pass over the sensor because this will cause an incorrect headspeed reading.

Now follow the helicopter power-on procedure and arm the helicopter ESC. Be sure to stand a reasonable distance away. Slowly spool up the helicopter using the throttle stick and watch the tachometer reading. If the headspeed goes beyond the upper expected range, stop immediately, because the helicopter may throw a blade if the headspeed is too high.

If your headspeed is too high before you reach half stick (90% throttle), then you should use a pinion with a lower tooth count. If you are already using the smallest tooth count pinion, then you may need to lower the maximum throttle values to 85% or so to lower the headspeed slightly. Do not use a maximum throttle value of less than 85% because this may overheat the motor. See Section 30.1.10, “How ESCs work” for an explanation.

If your headspeed is still too low by the time you reach half stick (90% throttle) then you should try a pinion with a higher tooth count.

After you have adjusted the headspeed properly, copy the maximum throttle value to all points on the idle-up 1 throttle curve. If your maximum throttle value is still 90%, the idle-up 1 throttle curve should be:

Five point throttle curve: 90-90-90-90-90
Three point throttle curve: 90-90-90

http://www.swashplate.co.uk/ehbg-v17/ch13s04.html#N11A27

[aerobird]

On a micro heli, having a flat 'curve' may not be an issue, but a nitro heli definitely does not have that kind of settings.

Ideally, the headspeed should be the same throughout ALL throttle settings. It's the collective pitch that decides if the heli goes up or down.

Since the greater the pitch (either negative or positive), the more drag it creates, this would bogg down the engine (or motor). And likewise, at 0 deg pitch, there is very little drag, the engine will speed up. To compensate for drag, the throttle curve at Idle Up is a 'U' shape.