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6 EX GOING INTO FAILSAFE

PostPosted: Wed Feb 25, 2009 9:28 am
by Merv49
I've been having an issue with my 6EX apparently going into failsafe mode. I notice this problem when on a run and all of a sudden my sails are pulled in from full out. I can immediately reset by going to low throttle position on the transmitter and then back to high and everything works fine again.

I'm using a 7.2V battery so it's not battery failsafe or lack of voltage. During these incidents the rudder remains useable and I'm having this problem at what I consider very close range (less than 100 ft at times).

I've looked over everything and don't see what could be causing the problem. Is anyone else having this difficulty?

Merv

PostPosted: Wed Feb 25, 2009 9:37 am
by bigfoot55
I had a similar type problem but it was the armature on the RMG winch that was the culprit. Intermittant then finally quit. If you have that winch, you should check with Rob at RMG.

PostPosted: Wed Feb 25, 2009 9:51 am
by DBrawner
Merv,
Tom is correct that it's the RMG going into failsafe, not the transmitter. For some reason, the winch believes it's not getting the right amount of power. This is when I would look at how it's wired and current draw.

The rudder continues to work when the winch is in failsafe. You may also want to remove battery checking in the winch programming. That is the only feature that I have ever had a problem with on an RMG.

DB

PostPosted: Wed Feb 25, 2009 12:46 pm
by s vernon
A few years ago I had the same problem with a PCM radio. Every thirty seconds on a run the sails would sheet in. I got so I would sheet slightly in then back out before it happened.

This was with a T6XAS radio in PCM mode. I put a Skysport rcvr in the boat and switched the radio to PPM and the problem went away.

I always figured it had something to do with some sort of fail-safe in the radio that was out of whack and was only active in PCM mode.

I wonder if yours is happening like clock-work like mine was. Every 30 seconds from what I remember.

Scott

PostPosted: Wed Feb 25, 2009 1:13 pm
by Albert Stall
I too had the same problem just recently and it turned out that in my case, the battery connection was not seated in the receiver resulting in a low voltage condition and it was the RX causing the problem not the winch. I did call Futaba and they stated that the "low throttle" (in our case, sheet servo) is a safety measure programmed in the TX. Check your Futaba manual.

There is also a voltage regulator in the winch which I bypassed by using the "Alternate Connections" wiring shown in the RMG winch manual. This bypasses the internal winch regulator so you don't have to worry about that cutting out at low voltage. I did not install a separate winch switch but wired with only the RX switch in the circuit. As an added precaution, cycle your batteries and make sure it is not the cause of your problem.

As an aside, this past Sunday at the Palm Beach Gardens Regatta, I started having rudder problems. By a process of elimination, it turned out to be a bad pot (potentiometer) in the TX. My TX is only a year and a month old and I'm hoping they don't charge for replacement. The way you check for a faulty pot is to move the sticks slowly and observe if there is any jumping or hesitation in movement. It should be absolutely smooth movement. To be sure it's the pot and not the servo, connect the servo to another channel and observe if the condition persists.

Also, check out RMG'S info at the Electronics folder under "Experimental findings, current draw.

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Merv49</i>

I've been having an issue with my 6EX apparently going into failsafe mode. I notice this problem when on a run and all of a sudden my sails are pulled in from full out. I can immediately reset by going to low throttle position on the transmitter and then back to high and everything works fine again.

I'm using a 7.2V battery so it's not battery failsafe or lack of voltage. During these incidents the rudder remains useable and I'm having this problem at what I consider very close range (less than 100 ft at times).

I've looked over everything and don't see what could be causing the problem. Is anyone else having this difficulty?

Merv

<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

Al Stall

PostPosted: Wed Feb 25, 2009 3:49 pm
by Merv49
Well, it turns out that the problem is in the voltage regulator that I used to step down the voltage from my six cell battery to power the RX. I hadn't thought to check downstream of it to see if it was putting out the proper voltage. It turns out my 5 volt regulator was only putting out 4.8 volts and when under load the voltage to the RX was reading 3.6 to 3.9. which put the RX throttle channel in failsafe mode. DUHHHHHH!! This regulator was supposed to be rated at 10 amps but apparently it was defective. Out with the 7.2 battery and the voltage regulator. A six volt Batt with dual outputs to continue to bypass the winch regulator will allow me to keep it simple like I should have done in the first place.[:D][:D]

PostPosted: Wed Feb 25, 2009 8:07 pm
by greerdr
I think Al hit it.
Use the "Alternate wiring scheme" from RMG to get around this problem.

R.C.Greer

PostPosted: Wed Feb 25, 2009 9:35 pm
by Rick West
You might read the two Phantom of the Bilge articles on the Building Site. A long time ago when we decided we needed higher torque servos the Phantom moved in.

It might not be the problem but it sure sounds familiar. At any rate it is good information.


...94 [8D]

PostPosted: Wed Feb 25, 2009 11:29 pm
by Merv49
The Phantom of the bildge article led me to install a seperate voltage regulator since I was using a 7.2 volt battery. I should have installed one that wasn't faulty.[:D][:D]