P80 Shutdown

P80 Shutdown
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P80 Shutdown - 7/17/2004 10:25:29 PM

kelly vallee

Posts: 231
Joined: 6/18/2002
From: Granby, QC, CANADA
Status: offline

I need help, I have a P80 that is 3 and half years old. I have been getting failsafe on the last 10 or so takeoff, it happens about a minute to two minutes in the air. The turbine go to idle, I check on the ECU ( v4.00e) and it give me a failsafe, this is about the 15 time we use the failsafe in the ECU. We never use it before, I tried it without the failsafe program in the ECU and I still get a failsafe and the turbine go to idle, but I dont get a failsafe count on the ECU. I have a Futuba 9wc, the plane have 7 servos ( 2 digital), a jetcat valve for brake, a 1500 mah battery for the plane, and I switch the battery for another and still the same. I also seen a 75000 rpm the turbine for a second or two, looks like it skips on spool up and then kick in to the max. The fuel pump max voltage is 2.35v, temp is good. Do you have any suggesttion, the season is to short up here in Canada to waste it. If I cancel the failsafe with a switch in the tranmitter the turbine go back to full power. Kelly

Post #: 1

RE: P80 Shutdown - 7/19/2004 12:17:40 AM

kelly vallee

Posts: 231
Joined: 6/18/2002
From: Granby, QC, CANADA
Status: offline

I have been making more test, and I would like to know if the ECU pulls any amount of current from the receiver. I check all servo, valve and receiver and they all look OK. There is something in the plane that is pulling a large amount of current, causing the receiver to go into failsafe mode.

(in reply to kelly vallee)

Post #: 2

RE: P80 Shutdown - 7/21/2004 2:35:59 AM

kelly vallee

Posts: 231
Joined: 6/18/2002
From: Granby, QC, CANADA
Status: offline

Where is MR_MATT, my post has been up for days and I haven't had a answer. I have not seen him post replies on none of the of post.

(in reply to kelly vallee)

Post #: 3

RE: P80 Shutdown - 7/21/2004 3:47:26 AM

mr_matt

Posts: 6776
Joined: 12/7/2001
From: Oak Park, CA,
Status: offline

Sorry I missed this, I do have a real job that pays for turbines.

THe ECU definitely draws power for the RX pack, but not very much. I doubt the ECU is pulling down the pack.

As for why you are getting failsafes, that probabaly has little to do with the ECU. Have you changed out the battery? If you have been able top get 10 failsafes then it sounds very repeatable. I would start by changing the battery and the rx harness to make sure the voltage is stable.

Unfortunately, I cannot understand your message. This part:

<<The turbine go to idle, I check on the ECU ( v4.00e) and it give me a failsafe, this is about the 15 time we use the failsafe in the ECU. We never use it before, I tried it without the failsafe program in the ECU and I still get a failsafe and the turbine go to idle, but I dont get a failsafe count on the ECU. I have a Futuba 9wc, the plane have 7 servos ( 2 digital), a jetcat valve for brake, a 1500 mah battery for the plane, and I switch the battery for another and still the same. I also seen a 75000 rpm the turbine for a second or two, looks like it skips on spool up and then kick in to the max. >>

THis is hard to understand. Do you have the failsafe programming enabled in the ECU?

_____________________________

Matt
JetCat rep

(in reply to kelly vallee)

Post #: 4

RE: P80 Shutdown - 7/21/2004 3:56:54 PM

Gordon Mc

Posts: 6864
Joined: 1/30/2002
From: San Jose, CA,
Status: online

I'd suggest buying and using one of these: http://horizon.hobbyshopnow.com/products/description.asp?prod=HAN172

If the failsafe is definitely being caused by the voltage getting dragged down (as oposed to an actual RF source interfering), then this simple meter will allow you to (a) plug it in between the ECU and the RX to show how little of the RX battery power the ECU is drawing; (b) plug it between the receiver and each servo in turn, to see if one or more of the servos is pulling an abnormal amount of current.

Gordon

_____________________________

"Facts do not cease to exist because they are ignored." - Aldous Huxley
"He who establishes his argument by noise and command shows that his reason is weak." - Michel de Montaigne

(in reply to mr_matt)

Post #: 5

RE: P80 Shutdown - 7/21/2004 10:53:18 PM

kelly vallee

Posts: 231
Joined: 6/18/2002
From: Granby, QC, CANADA
Status: offline

We had the failsafe on the ECU for about 6 flights and we disable it and still getting the same thing. The next step we will put a 2800 mah battery with a new switch and extension, and see what kind of power it will take for one flight.

I also seen at 75000 rpm the turbine for a one or two seconds, looks like it skips on spool up and then kick in to the max.

Any ideas would be helpful!!!

(in reply to Gordon Mc)

Post #: 6

RE: P80 Shutdown - 7/21/2004 11:29:53 PM

mr_matt

Posts: 6776
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From: Oak Park, CA,
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quote:

ORIGINAL: kelly vallee

We had the failsafe on the ECU for about 6 flights and we disable it and still getting the same thing.

This is what I am not getting....what does the "same thing" mean? Do you mean that you are disabling "ECU failsafe" and still you are getting failsafe on the ECU?

_____________________________

Matt
JetCat rep

(in reply to kelly vallee)

Post #: 7

RE: P80 Shutdown - 7/22/2004 12:52:02 AM

kelly vallee

Posts: 231
Joined: 6/18/2002
From: Granby, QC, CANADA
Status: offline

YES!! I disable the ECU failsafe and I'm still getting the failsafe error. I think the the failsafe that is built-in the Futaba 9Z for the battery is the one thing that signals the ECU to go to idle. I then I cancel the failsafe with a switch on the TX and the turbine come back, and I have full control. I'm gets like to know want amount of power should the ECU pull from the receiver.

(in reply to mr_matt)

Post #: 8

RE: P80 Shutdown - 7/25/2004 12:37:28 PM

kelly vallee

Posts: 231
Joined: 6/18/2002
From: Granby, QC, CANADA
Status: offline

I came back from a fun-fly yesterday and I was talking to people and they are telling me that JETCAT recommends to use a 6 volt battery for the receiver. I have always use a 4.8 volt battery with no problem, is this true or not? They say the voltage drop is less on 6 volts and this helps with the failsafe not to kick-in, since the voltage is higher it doesn't drop passe has fast and low as a 4.8 volt battery to activate the battery failsafe. Thank you.

(in reply to kelly vallee)

Post #: 9

RE: P80 Shutdown - 7/25/2004 5:31:43 PM

mr_matt

Posts: 6776
Joined: 12/7/2001
From: Oak Park, CA,
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I don't think it is mandatory to use a 5 cell Rx battery with the ECU

I noticed something from your first post:

quote:

ORIGINAL: kelly vallee
I tried it without the failsafe program in the ECU and I still get a failsafe and the turbine go to idle, but I dont get a failsafe count on the ECU.

So it sounds to me like you did indeed disable the JetCat ECU failsafe functionality. If this is the case, I am pretty sure you are getting the failsafe from the default settings of the 9ZAP, not from the ECU.

The 9ZAP has a feature called battery failsafe, and it is set as a default to be enabled. If I remember correctly, this is set for 3.3 volts. My guess is that your set up is drawing the receiver voltage down below 3.3 V and you are getting the battery failsafe from the receiver. This could be caused by a long battery lead, weak switch, excessive servo current draw, etc. In this case, a higher voltage battery will indeed help. And this has nothing to do with the ECU.

Good luck,

_____________________________

Matt
JetCat rep

(in reply to kelly vallee)

Post #: 10

RE: P80 Shutdown - 7/26/2004 3:25:53 AM

Gordon Mc

Posts: 6864
Joined: 1/30/2002
From: San Jose, CA,
Status: online

quote:

ORIGINAL: mr_matt
The 9ZAP has a feature called battery failsafe, and it is set as a default to be enabled. If I remember correctly, this is set for 3.3 volts. My guess is that your set up is drawing the receiver voltage down below 3.3 V and you are getting the battery failsafe from the receiver. This could be caused by a long battery lead, weak switch, excessive servo current draw, etc. In this case, a higher voltage battery will indeed help.

Matt - hope you don't mind me butting in here, in your forum ... if so, lemme know and I'll bug out

While a higher voltage battery may indeed cause Kelly to no longer see the problem, may I suggest that before resorting to using a higher supply voltage, the cause of the voltage drop should be determined if at all possible (especially if this same setup used to work ok, but now suddenly has problems). Otherwise, simply plugging in a higher voltage battery could be masking the problem, not solving it. e.g. if a degrading switch or connector is causing the problem, it may continue to get worse until it causes an all-out failure.

Checking the voltage throughout the system, and the current draw per servo (including "loading" the servo) may be a pain in the butt to do, but it could save the model as well as someone's life.

Gordon

_____________________________

"Facts do not cease to exist because they are ignored." - Aldous Huxley
"He who establishes his argument by noise and command shows that his reason is weak." - Michel de Montaigne

(in reply to mr_matt)

Post #: 11

RE: P80 Shutdown - 7/26/2004 4:14:32 AM

mr_matt

Posts: 6776
Joined: 12/7/2001
From: Oak Park, CA,
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I feel like no matter what, Futaba's basic voltage sensitivity is too high, so no matter what you do with wire guages or servos you should have the margin inherent in a higher voltage pack.

_____________________________

Matt
JetCat rep

(in reply to Gordon Mc)

Post #: 12

RE: P80 Shutdown - 7/26/2004 4:44:40 PM

kelly vallee

Posts: 231
Joined: 6/18/2002
From: Granby, QC, CANADA
Status: offline

We have check all servo and brake valve for a drain on the battery system and everything is OK. Sunday we changed the battery, extension, switch and still had the same problem. Then we changed ECU and still had the same problem, the next step is to change the receiver. I will keep you up to date on what happens.

(in reply to mr_matt)

Post #: 13

RE: P80 Shutdown - 7/27/2004 3:32:17 AM

kelly vallee

Posts: 231
Joined: 6/18/2002
From: Granby, QC, CANADA
Status: offline

Well, after many test we at last found that the receiver is the problem. I would like to thank Mr. Matt and everybody for the help, I would like to know if the new plastic cas of the 5.0 ver of the ECU fit directly over the 4.0 version of the ECU and the price of the box. If not what is the price to retrofit the older version ECU in the new 5.0 ECU box. Thank You again. Kelly

(in reply to kelly vallee)