SD Models 42% Extra 260 ARF Assembly

[Freddy Warbird]

I thought I would share my first 42% ARF assembly. This may take a few weeks, so here we go!

SD Models 42% Extra 260 ARF
Wing Span: 122"
Wing Area: 2666 Sq. in
Fuse Length: 111"
Engine: Desert Aircraft 150cc
Servos: Hitec HS-5955TG
Seiko PS-050
Control Arms: SWB
Extensions: AirWild Hobby's Silicon
Receiver: JR PCM
Power Equipment: Smart-Fly
RC Blimp: Tail Wheel, spinner
Batteries: Lithium Polymer

[Freddy Warbird]

This is a nice kit. All of the plane parts where well packed, and protected in the crate. All of the hardware is nicely separated in a train of individual plastic bags. I was surprised to find that none of the covering had wrinkles to iron out. That is rare! The only thing that bothers me is the instruction manual. There isn't one. So I guess I can start just about anywhere.

After giving the sub assemblies a once over, prefitting the the appendages, and while I am waiting for most of my equipment to arrive in the mail, I thought I would go ahead, and start with the landing gear, and wheel pants.

1) Removed Ultracoat from the mounting wholes with an soldering iron. Went over the mount area with iron prior to installation.
2) Deburred the mount using a Dremel, and file. Placed a section of foam inside the exhaust ducting to prevent any hot particals from attacking the ultracoat while grinding.
3) The fasteners have a self locking type nut, so just bolted in gear.

[Freddy Warbird]

4) For the pants themselves, Set wheel into opening, and marked the centerline.
5) Stand the pant up, measure 3/4" from initial mark, and awled the drill point.
6) Progresively drilled axle whole from a pilot to 41/64" to accept large axle nut. Nice, and sharp drills help! Careful when drilling. I know the pics don't show it, but the pant needs to be supported on the whole side while drilling, or it will vibrate like crazy, and ruin the pant.
7) Installed axle 272 loktite applied to threads.
8) Leveled Fuse, temporarily installed wheel and pant, parralled pant to bottom of fuse, and marked the location for the pant fasteners.
9) Awled drill point, and drilled out pant using a .167" drill.
10) Using a pair of channel locks, and 5 minute epoxy installed blind nuts
The wheel opening needed to be enlarged a bit for proper clearance
11) Installed pant, and secured fasteners with 242 Loktite.

[Freddy Warbird]

[Extra260]

NICE!!! This will be my next plane! Keep up the progress.

[Freddy Warbird]

Wheels are done! 242 Loctite paste on the collars, and pant screws. One less thing to do!

[Freddy Warbird]

Now For the cowl.
1) Installed lower, and upper halfs.
2) Applied blue tape to keep aligned.
3) Tailor measuring tape is perfect for measuring out the cowl fasteners. all the fasteners are spaced 1 1/4" apart from one another starting about 1/2" in from where the cowl meets the fuse.
4) Drilled and installed 14 per side (Dubro #525 No. 2 X 3/8" Button Head sheet metal screws). Its a clean look, but I ran out, and will continue tomorrow.

[Freddy Warbird]

OK. Got all my screws, and finished installing them into the cowl. Some additional strips of wood are needed for the ends of the cowl where the two halves meet at the front opening.

[Freddy Warbird]

Now for the part of any model I dread. "HINGING!" First, I must say that Robart hinges ought to be the standard for ARF's. They are so... much easier to install, and seal than the kind that came with this model. Besides that, they look better.

Like the Robart hinge points, I decided to glue the flat style hinges in with Gorilla glue.
1)I Ironed the hinge line, and used a thin artist paint brush to wick water into the hinge slots for kicking the glue. (Use very little water, just enough to damped the wood.)
2) I made a spatula out of a scrape piece of ply, to use as a tool, to lay the glue in the hinge slots .
3) Sanded the hinge, and applied a couple of drops of oil to the hinge pivot.( clean off most of the oil without speading it onto the glue surface of the hinge.)
4) Using an acid brush, I applied a very thin coat of glue to the hinges themselves.
5) Instaled all the hinges at the same time, flexing the control surfaces a few times to align the hinges, and wiping clean any glue that squeezed out. Taped the control surface to the wing panel, removing periodcally to clean expanding glue off the hinges, and flexing the controls again. (Repeat until the glue stops foaming.)
There is no need to use an excessisve amount of glue. The glue expands, and to much can ruin the wings.

[Freddy Warbird]

Sealing the control surfaces takes a long time with the way I'm doing it, but it gives the hinge line a finished look, and I like it. I used Ulracoat, and "color matched " both the top, and the bottom. I have started, and completed one panel. It will probably take me a week to finish the other three. Thank God the main wings are straight across blue to blue, and white to white on the bottom. As you can see, the horzontals are "not." The horzontals are a nightmare. But....with 70 degrees of available throw, bevel to bevel, it will be worth the work. ahhhhhh. Now back to work!

[TonyThomasian]

Looks Good! I like the screws you used for the cowl. makes it look real clean!

[Freddy Warbird]

Thanks! You need a really good allen wrench to spin them, and out. Hardened tipped.

[adrian]

Freddy marvelous job - I am glad youre a few weeks ahead of me so now I will make no mistakes - lol

keep up the good work and the pics!!!

[cbk07]

Freddy, looks great. Nice build. I put togeter one of these last June and it is a sweet, very light flying plane. One reccomendation I have is to replace the axles with Dubros or something like that. A couple of us up here have had the spot welds break and the axle will seperate from the screw. Keep up the good work! Craig

[Freddy Warbird]

	Quote:
	cbk07: A couple of us up here have had the spot welds break and the axle will seperate from the screw. Keep up the good work! Craig

That was the first thing I staired at when looking over the axles. "The welds." I still can't understand, other than cost, why SD didn't use Robarts. I would have paid an extra $50.00 to have the appendages pre drilled for them. But, I must say, that this Gorilla glue in like concrete once dried. My hinges are locked in but good!