Remote Kill Switches for Gas Engines
#26
My Feedback: (7)
RE: Remote Kill Switches for Gas Engines
ORIGINAL: Big_Bird
Dan, I agree, it's probably a CYA issue with Futaba. However, in a Tower add Tech Notes Dura Trax doesn't mention that their fail safe can't be used with aircraft and it's only $17.99.
Ken
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXHLV3
Dan, I agree, it's probably a CYA issue with Futaba. However, in a Tower add Tech Notes Dura Trax doesn't mention that their fail safe can't be used with aircraft and it's only $17.99.
Ken
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXHLV3
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This is the Duratrax Failsafe Unit.
FEATURES: Prevents runaway nitro or gasoline powered vehicles
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Notice, it says vehicles, not just cars and boats.
So as you have discovered, cheaper and useable.
#28
Senior Member
My Feedback: (1)
RE: Remote Kill Switches for Gas Engines
Floater, yes I did miss the part about it being for Ni-Cds only. I re read it again on the Tower web site and missed it there also. I then went to the Duratrax web page and missed it there also. This isn't the first time that I've missed something that I should have seen.
As far as 5 volts goes with this device, it doesn't know the difference from 5 volts produced by a Ni-Cd, a NiMH, or a Li-poly (with a regulator). DC is dc and if sufficient current is available the device can't tell the difference. I do question the 3.8 volt low battery protection for airplane use. Most planes would have already crashed at this point. This is obviously protection for the battery pack on ground or water models.
Ken
As far as 5 volts goes with this device, it doesn't know the difference from 5 volts produced by a Ni-Cd, a NiMH, or a Li-poly (with a regulator). DC is dc and if sufficient current is available the device can't tell the difference. I do question the 3.8 volt low battery protection for airplane use. Most planes would have already crashed at this point. This is obviously protection for the battery pack on ground or water models.
Ken
#29
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RE: Remote Kill Switches for Gas Engines
To my knowledge there is only one failsafe unit made that incorporates an engine kill feature in the event of a total loss of power from the reciever pack for whatever the reason. i.e. broken wire, connector becoming unplugged, batt pack failure, etc. All other failsafes work only if you have battery voltage to the receiver and cannot kill the engine or retard the throttle in the event of total receiver power failure.
Jim
Jim
#30
Senior Member
RE: Remote Kill Switches for Gas Engines
I do question the 3.8 volt low battery protection for airplane use. Most planes would have already crashed at this point.
I have had two low voltage throttle to failsafe with PCM (60 Ultimate on glow) many years ago without crash.
You are correct. At 3.8v the batteries are well under the 4.4v knee on the discharge curve. The speculation was that the voltage momentarily spiked to 3.8 and the electronics were smart enough to go to failsafe even though the average voltage was high enough to hurry up and land.
Don’t know how to prove or disprove the speculation. I was simply happy that the airplane was still in one piece. I was glad it worked.
Bill
#31
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RE: Remote Kill Switches for Gas Engines
The MVVS 1.60 gas can be killed by closing the throttle all the way. I had n experience this past season that convinced me that a kill switch is required however. My throttle linkage popped off at the carb (nylon ball link, since replaced with a bolt-through ball link) The carb stayed open just enough to keep the plane flying. I had a flight that was about an hour and a quarter long waiting for the fuel to run out. The thought that the RX battery could run out of juice before the fuel ran out didn't occur to me until later that day, and it made my skin crawl!
#32
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RE: Remote Kill Switches for Gas Engines
in my Ultimate Bibe, i used to have a fiber optic kill switch. i went for a period of time having mysterious dead-sticks and got to thinking, maybe the kill switch was momentarily intterupting the power to the ignition unit causing the problem.....so i removed it from the system.
later i found the problem (was a clunk problem). fixed it and have been flying fine ever since. (unfortunately, i didn't put the kill swith back in). [you know where this is going....]
last week i had thurs off and went out flying. on the first flight of the day about 7 minutes in, the throttle suddenly went to full (DA 50) and stayed there! i don't normally ever fly at full throttle except on "up" lines. well i flew the remainder of the flight at full, circling downwind from the runway awaiting the inevitable.
i got lucky, it stopped at just the right place. with a little help from my friend ("....thanks Scott") we got it down to an uneventful landing (that thing glides like a brick).
anyway, turns out the servo had failed and went to full travel and just held there. i think i need to get that kill switch back in the plane.....
David S. - Tampa, FL
later i found the problem (was a clunk problem). fixed it and have been flying fine ever since. (unfortunately, i didn't put the kill swith back in). [you know where this is going....]
last week i had thurs off and went out flying. on the first flight of the day about 7 minutes in, the throttle suddenly went to full (DA 50) and stayed there! i don't normally ever fly at full throttle except on "up" lines. well i flew the remainder of the flight at full, circling downwind from the runway awaiting the inevitable.
i got lucky, it stopped at just the right place. with a little help from my friend ("....thanks Scott") we got it down to an uneventful landing (that thing glides like a brick).
anyway, turns out the servo had failed and went to full travel and just held there. i think i need to get that kill switch back in the plane.....
David S. - Tampa, FL