Emergency shutdown method

[fabricator]

I see much ado about nothing, has anybody ever heard of a runaway Lister CS or listeroid?

[carbon-rod]

The issue is more around my automation of the engine. If for example the servo that controls the rack fails or opens fully or something crazy or the rack itself jamms because of the WVO build up or for whatever reason there needs to be a secondary (reliable) form of shutting down the engine.

[oiler]

It can and will run away...believe me
Mine did about a year ago. The rack got sticky from the wvo and the govenor was unable to close it.

[vdubnut62]

Sorry, but I have this mental picture of a runaway Lister hopping away across the fields, flywheels thrashing madly,
belching black smoke...........
Ron

[rcavictim]

Sorry, but I have this mental picture of a runaway Lister hopping away across the fields, flywheels thrashing madly,
belching black smoke...........
Ron

B&W or color?  Is this about a rebellious adolescent Lister running away from home?     Must be a Listeroid since Dursley Listers have impeccable grooming.

[Tom Reed]

Well if you're going to do a spring loaded flap. Just hold it open with a small pin and use the solenoid to pull the pin in an emergency. This would also allow manual engagement in an emergency. I know I managed to stick the hand crank on the shaft while trying to remove it. It was a bit nerve wracking having to reach past it flip the fuel lever, while it was barely hanging onto the crankshaft and spinning at 650 rpm. The rack on mine also got sticky from WVO and was over speeding when a large load was dropped.

[carbon-rod]

vdubnut was the Lister trying to make it to the next state where it could run free with the other listers?

The system would need to be directly connected to the spring loaded flap with the solenoid running continuously in order to open the flap. Basically it needs to be fail safe so that if the control circuit craps itself it will just shut down automatically and not require 12v to be injected by a control circuit, also if the power cable broke to the solenoid while it wasn't activated when you went to try and activate it for an emergency shutdown it wouldn't work.

[fabricator]

You could easily automate a roid with a morningstar RD1 relay driver, they are more like a logic controller, it includes timers and voltage and temperature activated features.

[Tom Reed]

Ok I see you want to be really really fail safe, not just an over speed shut down. As the Fab said, you'll need something with a timed delay to hold the flap open while the engine comes up to speed.

[carbon-rod]

yep this is the emergency shut down only, normal shut down and operating will be done by the rack, but if for some reason the engine speed or temperature goes out of bounds then it will shut it down using the flap.

I am building my own controller that will control the rack servo, monitor temperatures and also control the solenoid so in there I will be able to configure all the timings required for start up etc...

[fabricator]

OK, so if the thing is running away, it needs to pull the rack wide open, you could put together a Y branch in your intake big enough to hold a ball that will plug the intake pipe, put a small spring loaded detent in the Y branch, when the rack pulls wide open a cable could pull the detent down and the ball would fall into the intake pipe.
No solenoids, no fancy electronics, all controlled by the existing linkages.

[carbon-rod]

mmm this wouldn't work though if the rack was stuck?

I am all for simple, however I am kind of defeating the purpose by building a control system and adding electronics for it any way, but that's ok for my purpose as it doesn't need to be sitting in a field where it is required to be very reliable, for me I would rather a system that is fully automated, and because I have an electrical background that is actually half the fun automating thing is what I like to do..

[Tom Reed]

Fab, that's only 1 scenario, agreed probably the most likely, but they can run away by sucking the engine oil past the rings too.

[carbon-rod]

I'm hoping by introducing suction by closing off the intake it won't cause oil to suck up past the rings but I thought in the worst case scenario when I did have to shut it down with the flap at least it won't be able to suck in any air to combust the oil that it pulls past the rings so hopefully it should die pretty quickly...

Ill be checking the rack regularly and making sure its nice and free so hopefully there will never be a day where I need to use the flap, but I reckon it will be very handy if I do ever need it! I might also hook up an emergency stop button on my shed which is in series with the solenoid so I can shut it down manually while keeping my distance

[fabricator]

Fab, that's only 1 scenario, agreed probably the most likely, but they can run away by sucking the engine oil past the rings too.

They still need air for combustion.