Power cut and re-start

[Tim Smith]

Okay here is one .My power started freaking out :tongue
In mid flight my engine stops and then quickly restarts it has done it a few times now today and I have my needle out 2 turns the 7 th gallon of nitro. is it the glow plug or is it the fuel ? 30% cool power nitro .... I even get the same issue at 1 and a half turns out is rich or lean causing perhaps and its not the glow plug? I was forced to do an Auto from 12 feet once and broke a skid bracket Replaced it and re test flew with the same thing power engine cutting out and dying and then restarting

[Finless]

You sure your not going into lockout? If you set your FAIL SAFE to idle then it would act JUST like that.

I will never forget a few years back when i had a flight pack going bad... I was doing tic-tocs and the heli engine shut off (or so I thought). It went into BFS and went into throttle fail safe. I auto'ed down and landed. I started walking towards the heli and thought the engine was off... The freakin heli spooled back up because I was still in idle up! What happened was the battery recovered enough (because the servos were no longer being moved around) to put the RX back in normal!

Anyway make sure it's not a lock out or fail safe condition!

Bob

[Tim Smith]

Hello BoB :) you are one of my heros I hope you know.Thank you for all your hard work and advice in video form.
well I have a couple of sanyo 5 cell Nmhi 2700 Mah packs.I always check the voltage before each flight and I keep em full charged..As for the fail safe I don't even understand how any of it works in my JR 9303 because they dont tell you in the manual .They only show you how to find it thru the menu.So its an untouched feature in my radio.Yesterday I put a new 8900G tail servo on and I took the Futaba S9254 tail servo and switched it to the Thorotle servo .I did have to reverse it. And all seemed well but that is when I noticed this problem:hug:

[Finless]

My bet is by default the fail safe is set to low throttle stick. I don't know JR FM radios well enough to know if it has BFS (battery or before fail safe). What BFS does is if the RX sees the battery voltage drop below a certain level it will go into BFS which either puts the throttle to low stick OR will pulse the throttle up and down to let you know. You have command of all other servos.
Regular Fail safe is a radio lock out (loss of signal to the RX) and with that you have no stick control and the throttle goes to low stick. The other servos may HOLD last position or go to a preset position. Again I do not know the defaults for a JR radio.

So even by defaults in your radio you could be having BFS.

The reason I think you might be getting that is a engine RARELY can completely shut off and restart on its own! In fact I am not sure I have ever seen that happen where the motor shuts off and restarts in flight....

Bob

[wacojoe]

I have read somewhere that an engine can "backfire" due to a rich condition and start running backwards in flight. I have had this happen on a plane but it was a 4 stroke and it was during ground run while adjusting the mixture at idle. Anyway in the forum a guy said it happened him on a heli and he auto'd down and the engine was running backwards. This is just what I read. What finless said makes more sence, but I thought i would share that with you.

[Tim Smith]

Well just to be certain and safe ,I went back to the bench and took the Futaba Servo off and put the spektrum 821 back on and Re reversed the setting as it was before yesterday.You are probly right about the low voltage.I noticed after I put the 8900g Servo on the day before that my pack voltage was depleating a bit quicker And then I put that Futaba tail servo on for the thorottle and I bet between the two they would draw the voltage down to the point that you reffer to and fail safe could kik in(is that what I understand).I do not have a voltage regulator on this heli .So every thing is running at 6.0v .Hopfully this will cure that scarey problem. Yes the Engine would acutally shut completely off then refire about 1 second later .I thought maybe I was to rich I was flying next to the Bay at sea level .
1 more question If at sea level should you run richer or leaner (I figure leaner since the air is denser) is that right? I guess I will have to get the carb smart and the ALign gover and put on this bird.
Back to the JR fail safe. I was messing around in there for the first time just now and noticed that in the upper right conner it shows stick positions and if you move the stick to a certain point and push clear it will lock that stick pos into the fail safe config some how.:hug::smokin: SO we have decided that it is not very wise of JR to manufacture some thing like a radio and put features in the thing that they do not give expamles of or explanations of how to use ( Especially something as important as FAIL SAFE for a RC Flying Model) they only show how to find it in the menu and the rest is all guess work unless you have a Finless in your cornner :lolol Dude you and your wackey Vids helped me get as far as I am now with these things , Because of you I have become an Edumacated Heli Freak :YeaBaby::noteworthy Thanks again Bob

[Finless]

OK I have never flown at altitude so cant say for sure but my thinking is as such.
Your needle valve sets your fuel to air mixture. So going RICH lets say means more fuel to air right? OK... At altitude the air is less dense (less molucules) right? So to me that would mean to get the right mixture you would have to lean the needle valve otherwise you would have more fuel to air.

As for failsafe... Here is a little more info for you.
There are 2 "camps" or arguements to how failsafe should be set on a helicopter. Both camps DO agree that throttle should fail safe to idle. But the rest is always a debate.
1 Camp says HOLD everything. The other camps says put everything at neutral.

So lets think about that and why I like it a certain way. If you are in a piro or a roll lets say and you lockout. For the hold camp, failsafe will hold the servos at the last input. So in the case of hold your heli would continue to roll or piro, etc. I personally don;t liek that idea. I am from the other camp. In this camp you would set your servos to go neutral. e.g. swash plate to level, tail to center stick. THis way to some extent the heli stops doing what you had it in when the lockout occurs.

So I set my fail safes to
Aileron to level or center stick
Elevator to level or center stick
Pitch to 0 pitch or throttle stick to center stick
Rudder to center stick
Gyro gain on HOLD (you don't want to shut off your gain)
Throttle to idle or low stick.

So there ya have fail safe 101 :)

Bob

[Tim Smith]

That Dialed me in great thank you.And as for the fail safe I belive netraul is the best thing to set it to as well.I mean if like you say it keep srolling or what ever your screwed ,at least in theroy if every thing returned to neutral you may have a change at recovery.,:noteworthy

You rrock the block Finnless Bob:thumbup:

[invertsick]

Hey timsmith,

You can do the failsafe setup during binding process of the rx and tx.

BTW r u using the 2.4 or pcm 9303?

serge

[Finless]

He says he sees the fail safe menus on his 9303 which a X9303 does not have. I suppose he could have a spektrum module though..... So I assumed h is on FM PCM RX like a JR 790 or something.

Bob

[Tim Smith]

7202 PCM JR 72mhz is the radio I have. Don't know why I told you that I musta been dreaming about having one.So I seem to have the fail safe figured out as well as the rich lean issue I got a ir spot temp gauge to help and watched Bob Break in flight video a few times till I got it in my head .Oh bob by the way That pattern that you fly the Figure 8 turn away from you with the loop looks like a ton of fast fun gonna try mastering that one:thumbup:
Now here is a new one for you .My heli came with the nylon bearing blocks ,So last week I changed them out for the Metal upgrades..........:thumbdown: Crappy Bearing Today when I spooled up I noticed this twicthing type sppin to to Main Rotors and imediatly spooled down shut it off and went to the bed of my pick up to see what was wrong now:confused:ANd after messing around I felt that the main shaft was tight and almost binding and ceasing but in a bumpy sort of poppy way as you would spin the shaft.SO I tore it back down and wouldn't you know it the new Bearing were crapping out already :dontknow:BangBut Luckly I found it so I put the old ones back on and it was to late to test fly .SO Tomorrow I will give it a hover and see if the carb fail safe issue has disapeared:smokin:
Thanks again for the advice

[chosen69]

So I set my fail safes to
Aileron to level or center stick
Elevator to level or center stick
Pitch to 0 pitch or throttle stick to center stick
Rudder to center stick
Gyro gain on HOLD (you don't want to shut off your gain)
Throttle to idle or low stick.

So there ya have fail safe 101 :)

Bob

Hey Bob,

so where would you set your flight mode switch when binding the X9303 for example ? Or in other words how would you make sure that the throttle is in idle or low stick ? Do you bind it with the flight mode switch set to normal mode and low stick ? Is the flight mode switch position stored too while binding and setting the failsafe ?

[Finless]

Chosen... I thought I covered that in a vid... But the X9303 is different depending on which RX you use! I used a AR7000 which what it does is HOLD everything but throttle on a lock out.

So how do you BIND for idle throttle? Well for bind I set my normal throttle curve to FLAT 0 across the board. This allows me to power up the TX at center throttle stick in NORMAL mode. On bind the throttle is at idle because of the normal throttle curve being set to 0% flat throttle. Once bound I change my normal throttle curve back to what is needed.

Now if your using a AR9000 you basically do the same procedure! It will failsafe to all center sticks (it has that feature if you bind at all center sticks) but because throttle is still set to a flat 0 on the normal curve... Thats what it will go to on a lock out!

Bob

[chosen69]

Chosen... I thought I covered that in a vid...

Sorry Bob, I guess that didn't come out right but my question was if it will store your flight mode switch position during the bind process i.e the pitch curve when it goes to failsafe as well ? Let's say you were in idleup when the lockout happens, the throttle would go to low stick (if programmed as you do with the throttle flat curve in normal mode) but does it go in normal pitch curve as well because you were in normal mode when you bound it ? If that makes sense ... :-))

[chosen69]

Disregard,

that was a stupid question just thinking about it !! When your locked out you don't have control anyway and by binding it with center stick you'll have zero pitch with idle power when it happens.... Sorry Bob, I'll have to remember to think before I talk.... happens to me all the time ... with sometimes less or more severe consequences ... :-))