aftermarket nosegear production?

brianwallis · #1 06-25-2007, 07:41 AM

Since the flip seems to be related to a resonance in the nosegear, is there anybody out there that would be willing to manufacture a nosegear that is different than the present nosewheel gear on the 6a and 7a? I'm thinking there are some awfully smart guys out there that have seen the resonance video of the nosegear and can calculate and design an aftermarket nosegear for the airplane....? (perhaps like the grumman line?(or adapt a aa-5 nose strut to the vans so we dont have to manufacture it?)
Best
Brian Wallis

rvpilot · #2 06-25-2007, 09:46 AM

Then what would break????

Phil · #3 06-25-2007, 09:56 AM

I've thought about finding a nose gear from a 172 or 182 and trying to fit it in somehow. But the chances of that happening aren't very good.

But I did wake up at 3AM last night with an idea, and I think it's a pretty good one too.

There are really two different problems.
1) Turf - The nose gear burying and causing the flip.
2) Asphalt - A general collapse from a not-so-graceful nosegear first landing.

The answer to #1 is pretty easy; put a bigger wheel there.

The answer to #2 is more challenging.

Have you ever taken a drinking straw and folded it? It's very easy to kink. But if you take straw #2, and make it a sleeve around straw #1, the support of the structure increases more than 2X.

Here's what I'd like to see:
- Before the landing gear is bent into position, sleeve it with a close fitting pipe. Then bend the entire assembly as one piece.

Weld it up to the engine mount as usual.

On the bottom side, cut it off a tad shorter and make allowances for a larger nose wheel.

There you go, a stronger nose gear assembly (Problem #2 is fixed) and a larger nose wheel (Problem #1 is fixed).

Honestly, I'm far from an expert and I'll admit that I'm very green when it comes to building. But it just sounds like a better way to skin the cat.

I can see some potential corrosion issues between the nosegear and sleeve. I'm sure a few drain holes in the sleeve would help. But not nearly as much as getting the right metals involved. I'd have to leave that to the metals experts.

It's just a thought.

Phil

airguy · #4 06-25-2007, 11:41 AM

I'm definitely all for a stronger gear - I'll accept the weight (and perhaps drag) penalty for a more robust gear that will be more forgiving of my Cessna-style crash-and-dash landing technique.

It will be a while before I get to that point, but I can say with a good deal of certainty that I won't be fitting the stock nosegear on mine - whether I have to design it myself or buy someone elses design.

pierre smith · #5 06-25-2007, 12:48 PM

I believe that a wooden stiffener front and rear, matching the current shape, then overlaid with several layers of carbon fiber cloth would sigificantly add to the overall stiffness with a small weight penalty.

As far as corrosion with carbon and steel, not sure how that issue would be resolved.

Regards,
Pierre

osxuser · #6 06-25-2007, 02:11 PM

How about using S-glass instead of carbon for the first few wraps.

Tandem46 · #7 06-25-2007, 02:26 PM

The easiest solution would be to move the nose wheel slightly aft, maybe 17 feet aft, back near or below the rudder. Oh wait, that design already exists, its called a tail dragger

Phil · #8 06-25-2007, 02:35 PM

Thanks for contributing an original idea, Tobin.

Pierre,

I kinda like the glass idea, but I worry it handling the shock factor. I guess if you can make wings or boats that bounce across a lake at 70mph, it should handle the shock of a bounced landing........

Intresting thought.

Phil

RV8RIVETER · #9 06-25-2007, 03:14 PM

Since you want to keep the gear leg from folding back and are looking to increase strength at minimal weight, glass or carbon definitely seems the best choice. But I would think you would not want to wrap it per sea. Why not a longitudinal build-up along the forward face of the gear to strengthen the leg from that bending moment, like a strap if you know what I mean? You could also shape the reinforcement to streamline the gear leg and kill two birds with one stone.

Just a thought.

L.Adamson · #10 06-25-2007, 03:34 PM

Quote:

Originally Posted by Phil

I kinda like the glass idea, but I worry it handling the shock factor. I guess if you can make wings or boats that bounce across a lake at 70mph, it should handle the shock of a bounced landing........

Intresting thought.

In the "good old days", as when my RV6A kit was produced; it was all wood stiffeners wound with fiberglass. The pre-made leg fairings didn't exist yet.

L.Adamson