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Elevator Bunge free play


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I have about 1/8 inch free play in my elevator measured at the rear edge.  All this free play appears to be in the elevator bunges.  Is this normal or are the nuts on the rear of the bunges supposed to be tightened to remove this free play?  Not sure if possible flutter is a issue with a small amount of free play?

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The bungee end nuts do not take up any free play- they are torqued down to hold the assembly together. The bungees have nothing to do with control system play- they are attached in parallel to the control system. If you were to remove them, the elevator play would remain the same.

When you say"play", do you mean that the spring in the bungee is not fully extended when supporting the weight of the elevator? It is normal for the weight of the elevator to compress the bungee spring, to some extent.

If you have play between the yoke and the elevator, then that is another thing entirely- start looking at all the rod ends, from the yoke to the tail. 

Edited by PilotCoyote
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The bungees incorporate springs in both directions, so there is always tension applied to the trim system. The play is usually in the rod ends. All the Mooney controls have some lost motion - there are a lot of rod ends. Dirt is abrasive and wears rod ends out. It’s a good idea to clean them and spray with Tri-Flow occasionally per the service manual. Tri-Flow is a dry film teflon lubricant. Don’t use oil or grease - it attracts more dirt. 

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I can’t find any description or instructions of how these bunges are constructed or supposed to be adjusted in the maintenance manual.  I assume there are two springs inside the bunge. Each to provide a dampening action in either direction. There appears to be some dead band or free play between the action of these springs around the neutral point.   There is a castle nut on the shaft that goes through the bunge.   Does anybody know what the purpose of this nut is and if it is supposed to be adjusted as part of rigging?

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1 hour ago, Gary0747 said:

I can’t find any description or instructions of how these bunges are constructed or supposed to be adjusted in the maintenance manual.  I assume there are two springs inside the bunge. Each to provide a dampening action in either direction. There appears to be some dead band or free play between the action of these springs around the neutral point.   There is a castle nut on the shaft that goes through the bunge.   Does anybody know what the purpose of this nut is and if it is supposed to be adjusted as part of rigging?

The bungee overall length is adjustable. The internal assembly is not adjustable. 

Elevator play has nothing to do with bungees. As stated above, most likely worn rod ends

20190828_172156.jpg

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16 hours ago, PilotCoyote said:

 

 

20190917_170940.jpg

Nice pictures! That's the spring inside the cartridge that pulls in one direction. There is an external spring that pulls in the other. The springs bias the elevator as the empennage moves with the trim. Without the bungees, the trim system would have to change the incidence of the tail by a greater amount to get the same trim effect. This system was used up through the J.

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