[TerryWighs]

Help anyone!!! On the rudder, and elevators (RV-8), I have installed the rod bearings, but am wondering about the jam nuts. Can those nuts just be snugged-up, or are they intended to be "torqued"?
Thanks

 

[IowaRV9Dreamer]

another related question

I think they should be torqued too (not sure to what value...) but I was wondering why Van didn't put a washer between the jam nut and the spar?

 

[DanH]

Correct torque never hurt a fastener.

Two notes. If you're using THIN jam nuts, you must use a lower torque value than for THICK jam nuts. If you use a crowfoot extension, you must do a quick calculation to find the correct torque wrench setting.

Dan

 

[szicree]

Set the crows foot at 90 degree to the wrench and no change in setting is required.

 

[Kevin Horton]

even if its not @ 90 the lever is negligible. were talking less than 1 inch so just torque to the high side of the torque value and you have room for error 80inch lbs on 8 inch wrench plus 1 inch lever = 71 actual http://www.engineersedge.com/manufacturing_spec/calculator/torque_adapter_extension.htm or just do the 90 deg and have zero error

You've got the math 180 degrees out. If you set the torque wrench at a particular value, it will always click at the same force value on its handle. The longer the extension, the longer the lever arm you are pulling on, and the more torque you are putting on the fastener. So, if you add an extension, you need to decrease the setting on the wrench.

If you want 80 ft-lb torque, with an 8 inch long wrench, and a 1 inch extension, you need to set the wrench to 71 lb.

 

[TerryWighs]

Thanks guys...now all I need is to find out the torque value for the jam nut???
Anyone know this torque value???

Also, in regards to "arm". Having trouble with this issue because the "arm" is measured from a different "plane" than the extension. When you use a "crow-foot" wrench, isn't the "arm" measurement from the nut to where the extension attaches...the length of the extension away from the arm should not matter???

 

[Kevin Horton]

Thanks guys...now all I need is to find out the torque value for the jam nut???
Anyone know this torque value???

There is a torque table in FAA AC43.13-1B. This is a 3/8-24 thread, with a thin, shear type nut. The table says 95-110 inch-lb. See page 7-9

 

[TerryWighs]

Thanks Kevin...have that publication, just couldn't find the data

 

[Jekyll]

Checked with Van's on this and was told to snug them down and not worry about torque.

Jekyll