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Nose gear rods Hard vs spring loaded


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First off disclaimer- I'm not advocating doing this to a flying airplane, this is just a head scratchier.

IIRC the electric nose gear rods were made with spring bungees (like the main gear rods) to help lower strain on the gear motor when going into the down and locked position. Obviously if they are loaded correctly (correct crush) the gear holds just fine as has been shown for decades. 

If the above is true, then why wouldn't the same postulation hold true for manual gear actuation? Wouldn't spring bungees work just as good for the manual gear airplanes? Would they reduce the down and locked loading of the Johnson bar going into the socket, just as we are pushing up against the hard wall with the solid rods? Does the airplane know what type of actuator is hooked up to the cross shaft? Johnson bar or electric? Does it care?  :-)

If they were the same length and adjustable to the same min/max length I'd love to get a pair of bungee nose rods and try them just to see what the Johnson bar loading is like (or different) in the down and locked position. I'd drag my jacks out to the airport and install them and rerig twice (once to try it out and once to put the correct ones back in before flight. 

It might prove interesting.  Anyone with any ideas to offer on the subject?

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I like your thinking Cliff!!

I strongly believe having the springs on the nose gear rods would prevent a half dozen nose wheel collapses each year. I think you can have a properly rigged manual gear airplane that puts too much stress on the nose truss fittings. Several examples I have seen here fail. 

There is enough stress to bend hardware, and the rods themselves if rigged incorrectly!! I've since replaced the rods and installed all new hardware on my electric nose gear rods. Lasar can reproduce the rods on an exchange basis. 

-Matt

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Sounds like a great idea and would result in reducing the force to move the last few inches to the lock down position. Too bad an old time Mooney Factory guy is no longer around to ask this design question of why no nose bunges.   I have never been able to see as clean of a break point of the nose over center link when checking preloads as I can see when checking the mains. Have others noted this?  I wonder if this is caused by not having bunges on the nose?  I have tried all kinds of things to try to provide more certanity of the nose over center break point including a dial indicator and feeler gauges.  I have found watching for movement of the nose gear doors is one way to detect the initial movement of the over center link.   I am still not as comfortable of measuring the break point on the nose gear. 

Edited by Gary0747
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The spring bungee rods should work just fine on a Johnson Bar system. I think Mooney didn't put them in because they are not necessary and cost extra money to make. 

The manual gear system actuates to a very precise position when down and locked. An electric motor always has some amount of uncertainty on where it will stop because of inertia and friction. They had to add the compliance to account for that uncertainty.

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