Align 600MX motor shutting down

[Granpappy]

You arent flying in 'normal mode' by any change (i.e. with a throttle curve starting at zero)?

Looks to me from the log that the 'Thottle in' signal dips sharply exactly at the time that the motor cuts. That could very well simply be caused by you pulling back on the collective in normal mode and cutting power to the motor. This also ties in with your description i.e. that power cut just as you tried to reduce collective. That's why i'd say NEVER fly in normal mode.

So i'd advise if you are using normal mode, dont,... Fly in idle up, preferably with governor.

Yes well it's a lesson learnt. (probably why I've always flown with curves instead of governor).

[Granpappy]

Well after a thorough going over, I was lucky. Just need skid arches and a bottom plate.

I really didn't want to crash this heli. They never feel the same after.

[Phill. H]

Granpappy, in your earlier post you stated you altered the pitch curve to - quote "I then set pitch curve to -5, 20, 35, 55, 85" what do those figures equate to in terms of max and min degrees of pitch. May be you have too much negative pitch on there and when you drop the stick as well as chopping the throttle the negative pitch is just helping to slam it into the ground. Just a thought but maybe less negative is best for your set up until it gets sorted electrically.

[Grumpy]

May be you have too much negative pitch on there and when you drop the stick as well as chopping the throttle the negative pitch is just helping to slam it into the ground. Just a thought but maybe less negative is best for your set up until it gets sorted electrically.

I'd argue the opposite.. By having only slight negative pitch available it makes it FAR more likely that you will need all you have, meaning you are likely to have to pull the collective stick all the way back and thus (in normal mode) cut the throttle.

The real problem is cutting the throttle. I'm thinking it wouldn't happen if normal mode wasn't used, i stopped ever using normal mode years ago for this very reason. Normal mode is just a crash looking for a place to happen.

[Grumpy]

Yes well it's a lesson learnt. (probably why I've always flown with curves instead of governor).

I'm not really following you on the governor comment Grandpappy? The way to avoid this again appears to be to not fly in a mode that has a throttle curve originating at zero... i.e. fly in idle up.

[Phill. H]

[QUOTE=Grumpy;1190334]I'd argue the opposite.. By having only slight negative pitch available it makes it FAR more likely that you will need all you have, meaning you are likely to have to pull the collective stick all the way back and thus (in normal mode) cut the throttle.

Not getting into argument over that as we don't know his pitch settings and I did not suggest slight negative just less negative pitch. Does look like from his setup that ESC is set for 3 governed headspeeds ( says gov mode fixed maybe it should read set RPM ) but if he is using a throttle curve ( linear 0%-100% ) starting at bottom stick instead of the flat lines at 30%, 70%, 100% that's not good, can see where throttle starts to ramp up to first gov H/S at 1.288ms (30%) @18 secs into graph, second headspeed (70%) starts to ramp up around 30 secs in but never gets there due to throttle being chopped and going below the (30%) 1.288ms throttle input setting @ 38secs dropping out of gov and killing motor power output. Similar thing happens at other end of graph just with different time stamps. So basically Granpappy you need flat line throttle curves of 30%, 70%, and 100% in your Tx to fly gov mode with the ESC set the way you have it at the moment. Just use throttle hold switch for disarming or arming the heli.

[Grumpy]

So basically Granpappy you need flat line throttle curves of 30%, 70%, and 100% in your Tx to fly gov mode with the ESC set the way you have it at the moment. Just use throttle hold switch for disarming or arming the heli.

100% agreed, exactly what I mentioned back in post #46 but doesn't appear to have been followed judging by the log.

[French Paul]

I'm interested in where you set your zero degrees of pitch at on your tx.
on mine I can use 0(100% neg) - 100(100%pos) so I set all my helis up at 50 which is midstick To then set 0 degrees.
on your setup you can go -5, so I'm lost as to where this translates to on you sticks.
if your tx is 100 neg to 100 pos with 0 being midstick then that would explain why you needed to reduce your pit curve as you have to rely on the motor to spool down to come down and the wind will make it climb as you don't have enough negative to fight it. Almost flying like a fixed pitch would....really bad in gov mode.
do you use a pitch gauge and what is your overall pitch range neg to pos?
Paul

[Phill. H]

+ 1 on trying to work that one out in my post #63 of this. thread. As you point out most of us have zero pitch at midstick, baffled. Basic pitch curve in my own Tx DX18 is shown as linear 0-25-50-75-100, 100neg to 100pos is shown in monitor servo travel

[Granpappy]

Granpappy, in your earlier post you stated you altered the pitch curve to - quote "I then set pitch curve to -5, 20, 35, 55, 85" what do those figures equate to in terms of max and min degrees of pitch. May be you have too much negative pitch on there and when you drop the stick as well as chopping the throttle the negative pitch is just helping to slam it into the ground. Just a thought but maybe less negative is best for your set up until it gets sorted electrically.

Sorry for the delay in replying. I've been on site today with no IT access.

Okay I just fly in normal mode as I have no intention yet of flying upside on this heli. Mechanical travel is set in the FBL to -12 deg through to +12 deg. Pitch curve on the transmitter is -100 to +100. Therefore Pitch= Throttle/(100/12). So -5 ,20,35,55,85 in the throttle equates to -0.6, 2.4, 4.2, 6.6, 10.2 degrees of pitch.

[Granpappy]

I'm not really following you on the governor comment Grandpappy? The way to avoid this again appears to be to not fly in a mode that has a throttle curve originating at zero... i.e. fly in idle up.

What I meant was I prefer using a curve instead of governor because you always have throttle control irrespective of where the collective is. I know it was daft to use normal mode with a governor and 0,30,30,30,30 set in the throttle, but I thought that if the heli dropped out of governor mode then the curve would take over and I would still have throttle control. I didn't expect :-
1. the motor to stop and not restart when putting collective back in. (like trying to flair it)
2. the constant rise in head speed to lift the heli with only a few degrees of pitch on. I was expecting 4 to 5 degrees before the heli came of the ground. With the faster head speed it lifted a lot earlier.

I used a 0 in the throttle curve instead of a straight line as backup in case either Throttle hold failed or the motor had a runaway up. The motor is what I am trying to determine the serviceability of, and using governor was probably ill advised in the first place under these circumstances.

That is why I said a lesson was learnt. If I was an expert on this then I would not have started the thread.

[Granpappy]

+ 1 on trying to work that one out in my post #63 of this. thread. As you point out most of us have zero pitch at midstick, baffled. Basic pitch curve in my own Tx DX18 is shown as linear 0-25-50-75-100, 100neg to 100pos is shown in monitor servo travel

I think I have answered that.

[Granpappy]

I'm interested in where you set your zero degrees of pitch at on your tx.
on mine I can use 0(100% neg) - 100(100%pos) so I set all my helis up at 50 which is midstick To then set 0 degrees.
on your setup you can go -5, so I'm lost as to where this translates to on you sticks.
if your tx is 100 neg to 100 pos with 0 being midstick then that would explain why you needed to reduce your pit curve as you have to rely on the motor to spool down to come down and the wind will make it climb as you don't have enough negative to fight it. Almost flying like a fixed pitch would....really bad in gov mode.
do you use a pitch gauge and what is your overall pitch range neg to pos?
Paul

I have a digital pitch gauge that I use to set 0 deg, +12 deg, -12 deg during mechanical and FBL set up. After that I just use maths to determine my pitch settings for flight.

[Phill. H]

Sorry for the delay in replying. I've been on site today with no IT access.

Okay I just fly in normal mode as I have no intention yet of flying upside on this heli. Mechanical travel is set in the FBL to -12 deg through to +12 deg. Pitch curve on the transmitter is -100 to +100. Therefore Pitch= Throttle/(100/12). So -5 ,20,35,55,85 in the throttle equates to -0.6, 2.4, 4.2, 6.6, 10.2 degrees of pitch.

Does that mean at bottom stick you only get 0.6 degrees negative, think maybe the way it's wrote down that's confusing me "So -5" and to -0.6" i'm taking as minus symbols, take it you are using them as indicators to the actual curve.

[Granpappy]

Does that mean at bottom stick you only get 0.6 degrees negative ?

Yes that is correct. Could probably do with a bit more.