Gear Tower Mod

[olyolson]

I’ve read most of the historical posts on the RV-8 gear tower mod but my plane is flying. Looks like this mod is best done during the build but I don’t have that option. Anyone done it to a finished flying -8?

Lots of good posts with lists of required materials so just looking for input from anyone who’s done the mod “after the fact” so to speak.

Why do I want to do this? Because torquing the gear bolts are almost impossible with a helper and literally impossible by myself. I did purchase the newer NAS bolts, nuts, washers and the clips that enable the bolts to be put in from the top and the bolt heads secured so you can check the torque on the nuts at the bottom outside the airplane by yourself.

Inputs?

 

[DanH]

The "remove one web" mod could be done easily. The mod which more or less makes F-802C removable might be a little more work.
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[olyolson]

RV-8 Gear tower mod

Mine has the plans 2 hole towers. I think just removing the metal between the holes and making a nice oval around the existing holes might make the most sense. With the extra room I think I could get my hands in there to access the bolts.

Anyone done it to a flying -8?

 

[Brent]

Gear mod

I have just finished modifying mine so that the bolts are inserted from the top, with the correct high tensile nuts. Rather than cutting into the tower which is structural, you might think about cutting an access hole underneath which is in the non structural floor area. The bolt heads can be restrained by milling a piece to fit into the channel at the fuselage side.

More details if it interests you.

Regards, Brent

 

[claycookiemonster]

Relax, it'll be all right.

We were not flying, however my project fell into my hands at the QB stage, so the towers were complete exactly as the plans call for.

I think it's mostly a matter of courage. We cut out the lower web, and so now we have a hole on top and a longer opening on the bottom when the cover is removed. Remember, you're really only replacing the structure provided by that lower web between forward and aft edges of the opening. The rest of it is already open! By the time you cover the large lower opening with a well made cover, IMHO, you're better off than what the plans originally provided for. That right there is TLAR, so I yield to the engineers among us. I'm pretty sure the original tower material there is 0.040, so we replaced it with the same.

Use dimpled screws and platenuts when you make your cover. Put dimples into your new opening covers. You want the shear stress there to be taken up by the shape of the dimples, not just the shaft of the screws.

Our screws are spaced every 1.5 inches around the perimeter and the cover overlaps the opening by 5/8" all around.

We have since mounted the gear legs and sworn profusely at the tight space down there. For the life of me, I can't understand why anyone would struggle with the original design.

 

[Brent]

Gear legs

Hi Clay,
I like your modification, but I would suggest that you consider when you start bolting it all together, that you substitute those inappropriate stamped nuts. As I have mentioned in a previous post, I have modified my gear legs to be mounted with the bolts from the top and using full sized high tensile nuts.

Of casual interest perhaps, is that we have followed somewhat similar career paths. I flew mostly single seat in the Royal Navy, followed by thirty years with American…….. small world. This is my second RV build, the previous one was an RV 9a.

Regards, Brent

 

[Brent]

Gear legs

Hi Clay,
I like your modification, but I would suggest that you consider, when you start bolting it all together, that you substitute those inappropriate stamped nuts. As I have mentioned in a previous post, I have modified my gear legs to be mounted with the bolts from the top and using full sized high tensile nuts.

Of casual interest perhaps, is that we have followed somewhat similar career paths. I flew mostly single seat in the Royal Navy, followed by thirty years with American…….. small world. This is my second RV build, the previous one was an RV 9a.

Regards, Brent