Author Topic: Engine for natural gas generator  (Read 24680 times)

Procrustes

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Re: Engine for natural gas generator
« Reply #45 on: September 20, 2006, 08:40:12 PM »
You don't have to use a linear actuator.  I'd probably use a rotary actuator (stepper motor) with a pulley and cable.  You can get the cables and pulleys out of the junkyard for nearly nothing - anytyhing with fuel injection uses a single throttle body with cable-and-pulley control.  Another option would be a model airplane servo.  attatch with a spring and put a solenoid opposite for a force-close emergency shutoff.

Great ideas.  I've seen a linear actuator, the threaded rod type, that has configurable stops, basically contact switches that you can move back and forth to limit the fore and aft motion.  I don't know the brand of that actuator.  Without configurable stops I'll have to design an armature with trial and error and risk burning out the servo.

You don't happen to know if RC servos or fuel injection mechanisms have something similar, do you?  Thanks again for the idea.

aqmxv

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Re: Engine for natural gas generator
« Reply #46 on: September 21, 2006, 04:59:31 PM »
The RC servos definitely have travel stops - they're built in for airplane use, since every linkage is different.  Get the big ones for the 1/4 scale models - they're stronger.  The servo will respond to more motion input after hitting the stop with no motion.  It knows it's maxed out, so just won't do anything.

Travel stops for the injection stuff? definitely.  Usually they're part of the throttle body assembly, though, so this might not apply for you.

Now the good news - if you decided to go the automotive route, there are travel limit microswitches usually for idle and full throttle operation - to tell the computer that it's in idle mode or that it should go to power enrichment.  These are generally mounted on the other side of the throttle body shaft from the cable pulley.
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Procrustes

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Re: Engine for natural gas generator
« Reply #47 on: September 21, 2006, 06:40:27 PM »
The RC servos definitely have travel stops - they're built in for airplane use, since every linkage is different.  Get the big ones for the 1/4 scale models - they're stronger.  The servo will respond to more motion input after hitting the stop with no motion.  It knows it's maxed out, so just won't do anything.

Travel stops for the injection stuff? definitely.  Usually they're part of the throttle body assembly, though, so this might not apply for you.

Now the good news - if you decided to go the automotive route, there are travel limit microswitches usually for idle and full throttle operation - to tell the computer that it's in idle mode or that it should go to power enrichment.  These are generally mounted on the other side of the throttle body shaft from the cable pulley.

Excellent.  Thanks so much.