Amp spikes correct?

[Wogboy]

Hello,

Attached is a typical download from a flight with my Logo 400 Vbar running the Hacker 1350kV motor and 70A ESC. I'm running an 18T pinion at 77% governed which is giving approx 2600 rpm headspeed. I'd describe my flying style as "intermediate".

My question is with regard to the Amp spikes on my graphs. Are these legitimate readings, or just anomalies or hiccups in the recording? There is an associated drop in rpm and Volts, but the Amp spikes are considerably higher in magnitude. If these are real, I'm concerned at the amount I'm pulling during manoeuvres, but maybe they are false readings like the spike in rpm at the beginning of the recording which I now know is associated with the ESC beeps at power up. Any ideas?

Logger is Eagletree V3, and I've tried re-zeroing sensors.

[andrewt1971]

I'm no expert but the way everything lines up I'd say those amps spikes are real.
I can get similar numbers from my protos (different motor and esc combination, but similar size and weight heli) if i'm heavy handed on the pitch.

Could you log a flight whilst recording the collective channel and see if the spikes coincide with heavy loads?

[Wogboy]

Hi Andrew,

The Amp spikes to me seem higher than what I've seen for other similar helis. Unfortunately I can't record the collective channel during flights as I don't have the add-on for this.

[andrewt1971]

There is a throttle logging channel built in to the eagletree, instead of plugging in the throttle (which is constant) feed in the collective signal from a spare channel on the rx, if you have one.

Otherwise 500 watts with 1200 watt peaks doesn't seem too bad. Could you go down a tooth on the pinion and up the gov to get the same headspeed, it may reduce the spikes slightly?

[Ecklund1]

I agree. I think it would be interesting to see the left stick graphed as well. I'm going to try that on mine. I've gotten spikes that seem to be too short and too high and wished I knew what my stick movements were at that moment to see if it's noise or real.

[Big Fil]

Honestly I don't see anything out of the ordinary with your amp spikes for the size bird your running. Those spikes are in most cases collective pops. Here's a graph done on my Logo 600 and you can see high spikes can be normal throughout a flight when getting on the collective.

[Wogboy]

Thanks, it sounds like they are legitimate readings. I wasn't sure with the false RPM indications I am also getting. It is a little concerning and I didn't think it would be pulling that many Amps during my manoeuvring, but I guess they're probably fine for the electronics as they're only momentary.

[Big Fil]

The false rpm readings are due to turn on beeps. If you run a castle they beep every so often after turn on and they show. The other anomaly always shows up at the start of the flight and is due to the soft start. Mine always showed the soft start as well but one great way to get rid of it is to have your logger only start recording when current is greater than 5A. This prevents all the dead time between pluggin in and actually starting the flight. The other way is to crop it out when you have the graph up by dragging a box around the data you want like you would in windows.

[Wogboy]

I'll give cropping a go. I tried using a trigger to start recording but this caused my RPM sensor to give false readings.

[RCSavager]

As a start trigger I've used the timed feature. I set it to start logging after 30 seconds of being powered on. You can adjust that of course but it gives me time to get the body on and walk away as I'm spooling up. But that cropping idea I didn't know about and I'm all over that one if it works. Great tip man, thanks.