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Section 40a-05-Castle Nuts?

Stockmanreef

Well Known Member
I assume that the castle nuts for the nose gear leg don't have to be torqued and just have to be snug. Snug enough that the bolt rotates with the leg as it moves.

Thanks
ken
 
In this case, you want your nose gear leg to be able to pivot on the axis shared with those bolts. It's part of your "shocks", in conjunction with the stack of J-11968-14 (U-01407) Elastomer Pads and U-01416 Nose Gear Link Assembly.

From page 5-20:

FASTENERS AS PIVOT POINTS
In specific cases, bolts are intended to be used as axis of rotation. The most common example is the attachment of control system cables. Here, it is intended that the cable end fitting pivot on the bolt. In these instances, the nut must not be torqued to the standard torque value. Instead a castellated nut, safetied with a cotter pin, is used. Finger-tighten the nut, then install the cotter pin. The cable end fitting must pivot freely w hen the installation is complete.​

Of course, do not neglect to insert and properly bend the cotter pins.

Note: You will probably end up disconnecting U-01416 to accommodate later installation of the exhaust.




 
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I was wondering about this, even though it says finger tight, because I was wasn't sure what should rotate in this case the bolt or the bushing (greased) or both. In this instance, i was not sure, if the nut should be tightened down enough so that the bolt rotated with the nose gear and the bushing is what slid around when the nose gear moved. Or if both the bolt and the bushing should be able to slide around. When finger tight, the bolt does not move when the nose gear moves.

My thought was that if the nut was tightened down enough so that it moved with the nose gear (but not torqued), then it would not wear off the powder coating over time.

I guess, as usual, I am over thinking things.
 
In the case that there is a bushing, I think the bushing is acting as a bearing and the bot should not rotate relative to the bushing. If the bolt is only finger tight then it could be turning inside the bushing. often times, if not always, the bushing is slightly longer than the case.

I will be interested in the answer as I believe I have torqued mine to the spec.
 
I was wondering about this, even though it says finger tight, because I was wasn't sure what should rotate in this case the bolt or the bushing (greased) or both. In this instance, i was not sure, if the nut should be tightened down enough so that the bolt rotated with the nose gear and the bushing is what slid around when the nose gear moved. Or if both the bolt and the bushing should be able to slide around. When finger tight, the bolt does not move when the nose gear moves.

My thought was that if the nut was tightened down enough so that it moved with the nose gear (but not torqued), then it would not wear off the powder coating over time.

I guess, as usual, I am over thinking things.

I asked Vans' Builder Support about the tightness of those bolts on 27-Sep-16 (specifically relative to page 40A-05, Step 3 and 40A-06, Step 6). The response was (italics mine):

For the castle nuts, refer to Section 5 page 18 (now page 5-20) under "Fasteners As Pivot Points". In this case, with the AN7 bolts, I generally tighten them a little more than finger tight, the align the slots with the hole on the bolt before inserting the cotter pin.​
 
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I asked Vans' Builder Support about the tightness of those bolts on 27-Sep-16 (specifically relative to page 40A-05, Step 3 and 40A-06, Step 6). The response was (italics mine):

For the castle nuts, refer to Section 5 page 18 (now page 5-20) under "Fasteners As Pivot Points". In this case, with the AN7 bolts, I generally tighten them a little more than finger tight, the align the slots with the hole on the bolt before inserting the cotter pin.​

We might need a tie-breaker here as I had got my info from VANs support tech and they have confirmed that in area that there is a bushing, the bolt will get torqued as standard value. Other example of such place would be the aileron weldment or the stick pivot point in a RV7 which uses bushing and does not have bearing like the 14 does. Other places like the rudder cable attachment points that the bolt acts as a pivot point does not get torqued and only finger tight would be the correct way.
 
In cases where a bolt acts as the pivot/hinge point (such as the example of the clevis joint on a rudder cable end) the nut should be left loose enough to allow the joint to hinge with low friction.
In cases of a bushing, the bushing is intended to be constrained from rotating by clamping with the bolt but the bolt should still not be torqued to full value because the material typically used for the bushings can be compressed and distorted by doing so.
 
scott-

so what I said originally was correct? Snug down the bolt so that the bolt moves with the nose gear and the bushing is the part that rotates inside the engine mount.

Thanks
Ken
 
E-

So is putting the exhaust in place prior to the nose gear a "gotcha"?

Maybe a separate thread should be started with this as a discussion. I know that I would be pissed if I put the engine on and found out I had to release the nose gear to get the exhaust in place.

I went out and tried putting the tailpipe in with the nose gear link assembly "in place". As E stated, it does not look like it will go in with the assembly in place.

thanks
ken
 
E-

So is putting the exhaust in place prior to the nose gear a "gotcha"?

Maybe a separate thread should be started with this as a discussion. I know that I would be pissed if I put the engine on and found out I had to release the nose gear to get the exhaust in place.

I went out and tried putting the tailpipe in with the nose gear link assembly "in place". As E stated, it does not look like it will go in with the assembly in place.

thanks
ken
Ken,
No, that would not be an issue. To install the exhaust, the nose gear (portion in the picture) need to be removed to accommodate the installation of the tail pipe. It is actually pretty easy but will require to lift up the front of the plane off its nose gear.
 
scott-

so what I said originally was correct? Snug down the bolt so that the bolt moves with the nose gear and the bushing is the part that rotates inside the engine mount.

Thanks
Ken

Correct
Just confirm that the bushing is just slightly longer than the more in the strut so that you know for sure that the clamping force is on the bushing and not the strut end.
 
isn't it easier to just put in place now? Or will it be in the way? I will have to find an engine lift at some point, but I don't think that I will be able to have it around for a long time. Unless the local EAA has one.

I don't know what the timing is between mounting engine and putting on exhaust system.
 
E-

So is putting the exhaust in place prior to the nose gear a "gotcha"?

Maybe a separate thread should be started with this as a discussion. I know that I would be pissed if I put the engine on and found out I had to release the nose gear to get the exhaust in place.

I went out and tried putting the tailpipe in with the nose gear link assembly "in place". As E stated, it does not look like it will go in with the assembly in place.

thanks
ken

I have fitted that part of the exhaust numerous times without disconnecting the strut but i will admit it is a bit of a puzzle to do it.
It is also possible that there is a very slight variation from one system to the other that makes some fit and others not, but I have not had to disconnect the strut to install 3 different systems on an RV-14A.
 
isn't it easier to just put in place now? Or will it be in the way? I will have to find an engine lift at some point, but I don't think that I will be able to have it around for a long time. Unless the local EAA has one.

I don't know what the timing is between mounting engine and putting on exhaust system.

If you do have to disconnect it later you don't need an engine lift.

Think outside the box....

Add some weight to the tail and push the tail to the floor....lifting the weight entirely off of the nose gear and allowing you to do whatever you need.
 
yeah, I know I can push down on the tail. I was just being a pain. Also, I would not have to take anything apart. Although after building this long, I am used to putting it on, taking it off, repeat, repeat, repeat. I am really looking forward to the cowling. I understand that require a lot of repeating.
 
Ken,
No, that would not be an issue. To install the exhaust, the nose gear (portion in the picture) need to be removed to accommodate the installation of the tail pipe. It is actually pretty easy but will require to lift up the front of the plane off its nose gear.

No need to disconnect the nose gear to get the stock Vans exhaust tail pipe into the tunnel.
Gentle fiddling allows it to be installed from the forward or engine side, without much trouble.
In my case I had to do it twice!
 
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