Getting it on the Gear

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The first step in getting the fuselage on the landing gear is to hang the engine mount. The mount comes completely welded and powder coated, and really looks sharp! It seemed at first like the mount would not fit between the extrusions attached to the fuselage. It is really just a matter of easing it in. It's a tight fit, and if its canted off center, it won't go in.
Spacers are designed into the mount, presumably to allow for minor variations from plane to plane. This approach worked fine, and I was able to select the spacer thickness for a perfect fit. Drilling the bolt holes involved drilling throught the aluminum extrusion, the spacer, and the steel engine mount. The clamps ensured nothing moved while drilling.
I always have pleanty of help!
The mount is hung with countersunk 1/4" dia MS24694-S100 philips screws. However, the lower screws called out in the plans were too long and could not be seated properly.
On the lower two holes, I used shorter MS24694-S96 screws and low profile AN365-428 nuts as well. This took care of the interference problem.
The axles as they come from Sonex. The inside of the axle needed to be filed a bit to remove some powder coating, but otherwise fit perfectly.
I decided to drill the axles and gear legs separately. I first marked the proper location for the bolt hole on the axle, and then pilot drilled a #40 hole. The titanium gear leg was then inserted into the axle, and the pilot hole was used to set a mark on the gear leg.
Using this mark, the gear leg was drilled in the drill press to ensure the hole was straight and square.
I stepped up the holes using 4 different bit sizes to get to the 1/4" diameter needed: #40, 5/32", 7/32", 1/4". The smaller holes were pretty easy to drill. I used new bits and lots of WD-40, and paused whenever the bit got hot. The larger bits really heated up quickly towards the bottom of the hole. Too much friction along the sides of the hole that deep into the gear leg.
With the holes finished, the axle was attached to the gear leg with a stainless steel 1/4" bolt. This bolt was *tight*, and if I ever need to remove it, there will be lots of pounding involved!
The gear legs are captured in sockets integral to the engine mount. However, there was a bit of interference with the lower mount extrusions. I needed to remove some metal to create the proper clearance for the leg. Don't worry, this is normal.
This is another place my dremel tool earned its keep. A cut off wheel and sanding drum made this quick and easy.
Finaly, the gear leg is inserted into the socket.
Both legs are in.
The plans suggest using a board or length of angle to properly set the axle toe in. I used a length of straight steel pipe clamped across the front.
There is some interference from the axle socket, but the pipe would sit against the bottom. I then used a 0.060 thick shim against the inner portion of the axle, and rotated the gear leg by hand until the pipe sat flush across the shim (on the inside) and the threads (on the outside).
The upper bolt that holds the titanium leg in the socket needed a washer under the head so as not to rub the firewall. It is still a tight fit. With those two bolts now in place, the gear legs were finished.
The tail post channel is first made as part of the vertical stab. So at this point, I had to shift gears and make the vertical stabilizer. Once that was done, I took the tail post, fitted to it the tail wheel mount weldment, and attached them to the aft fuselage.
The tail wheel assembled.
Tail wheel and titanium rod mounted on the fuselage. The 2 AN4C-12A bolts that hold the titanium rod in place were just a bit too long. I ended up using 2 washers on each bolt. It worked fine, but should probably have AN4C-11A bolts instead.


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Updated: 2 May 05