Nose wheel casting installation

The Long-EZ nose wheel is a castering wheel (meaning it is free to swivel like the front of a shopping cart wheel - well a bit more fancy than that). Steering is controlled by differential braking on the main gear wheels. The assembly that attaches to the nose strut tip is NG401A (as referenced on page 13-4 in the plans). I purchased mine from Jack Wilhelmson (http://www.eznoselift.com).


Here is the NG401A assembly installed to the strut tip.


Ok... so let's discuss how I did it.

I started out by installing the strut back onto the fuselage (remember, at this point, the strut only has the NG6 pivot mechanism attached on the other end). This allowed me to swing the strut by hand. Mimicking a retracted position, I was able to mark the edges that needed to be cut to make the channel from F22 aft to the wheel well.



With the marks made, it was time to cut!


After removing the foam, the strut was now able to fully retract into position.


I should note that I had to trim a little bit more off from the F22 notch - I used a metal hand file to do this.


Once I was happy with the channel, I clamped the NG401A assembly onto the nose strut to test it out...


...and good thing I did test it out! Look at how the nose wheel stuck out below the fuselage bottom waterline...


NOT GOOD!!



So like with most hurdles that come along the way, I closed up shop and gave it very much thought as to: A) what is the root cause, and B) what can we do to fix it.

Since the strut was butting up against the fuselage floor, it couldn't be retracted any further (unless I cut out the channel and glass a modified tunnel for it). This led me to lean towards a shimming solution - by shimming the NG15 casting, I could rotate the entire NG401A mechanism such that the nose wheel would be tucked up higher.

So I built a shim out of plywood about 2" in length (the thick end being 0.19" thick and shimming down to zero) and just wide enough to fit snug inside the NG15 casting.



Notice how the thick end goes towards the strut tip so that the NG401A assembly would be lifted up higher into the wheel well...



So I placed the shim inside NG15, re-clamped the assembly onto the strut, and tested it out again... This time it was perfect! Notice how the wheel is now tucked up into the wheel well and does not protrude outside of the fuselage when retracted.




Now that I was happy with the shim, I needed to install it permanently. I started out by sanding everything nice and smooth - ready for bonding...



I drew a line where the shim needed to be placed and painted the strut tip with plain epoxy.


I then mixed up some wet flox and coated the underside of the shim...


...and placed it onto the strut tip. I made sure the thick end was oriented towards the end!


I then coated the top of the shim with plain epoxy and placed a 1 ply BID over it...


Wetted it out and let it cure over night.



Next day, I trimmed everything up and sanded everything smooth... getting it ready to install NG15 on permanently.


First, I got my hardware ready. The plans say to use AN525-10R24 bolts; however, builder hints in CP#51 suggests to go with AN3-14A (since some Long-EZ owners noticed that the AN525 bolts weren't as strong as the AN3 type bolts). So I ordered AN3-14A bolts and realized they were a tad too long. Case and point, when all was said and done I went with AN3-12A bolts.




Anywho, so my mom was visiting and I put her to work! Look at her go mixing up some resin!


I painted on plain epoxy to the strut tip and smothered the top with wet flox. I also added wet flox to the inside of the NG15 casting. Notice how I applied tape to the bore to prevent resin and/or flox from getting inside.


I pressed the casting into place and flipped it over. I then applied wet flox to the other side of the strut tip...


...and applied some wet flox to the foot rest (by the way, this foot rest replaces NG2 and is made out of stainless steel - also purchased from Jack Wilhelmson).


I placed it onto the strut and applied the hardware. I tighten the bolts a little at a time making an 'X' pattern such that the foot always remained level (in the roll orientation). As for the pitch orientation, it was slightly higher on one end, but this was expected since the shim is doing its job!


After everything was properly torqued, I filled in all the gaps with flox and let dry overnight.




With everything dry, it was time to reassemble NG401A together.


And there you have it! NG401A permanently bonded to the nose strut tip!


2 comments:

Tango Charlie said...

Yay for Mom! :)
I like the simple solution of a shim that you came up with for your problem. I notice that it only helps put a little more caster angle on the nosewheel with it in the extended position, which probably is not a bad thing. Thanks for sharing the snags you run into along the way, and the way you overcome them.
What is the purpose of the foot? Is that what contacts the ground when the plane is parked?

Ary Glantz said...

Thanks Tango Charlie!

The foot is meant to help minimize damage in the event of a wheels-up landing. The fuselage nose will have a bumper (the size of a hockey puck) that gets attached to the bottom of the F1-3 bulkhead - this bumper is what contacts the ground when the plane is parked (not the wheel foot).

However, I'm not sure if the foot was tested to see if it would actually come in contact with the ground before the nose with the extended nose mod.

Any who, this is what came in Jack Wilhelmson's kit so that's what I'm installing for now. If later I see it makes no sense to have the foot rest, I will probably replace it with the original flat panel plate.