Unfinished business- Frank's Li'l Roughneck- Sterling kit 1967

[Frank v B]

Next Project.  Sterling Models Li'l Roughneck.  22.5" span, 3 cells, E-Flite 180 and a 6 amp esc., 3 channel (rudder, elevator , throttle)

I have built this plane twice and never got it off the ground.  Am aiming to correct history by making it again.

First attempt- 1968- single channel .020 Pee Wee motor- never got it off the ground but it was a cute plane.  Looked like a small Astro Hog.
Second attempt- about 1990- again with an .020 but before GWS revolutionized miniature RC for the masses.  Never got it off the ground and got frustrated.
This attempt-  funny reading about the kit.  Posts on the build described the rock hard balsa that was a Sterling Trademark.  I will build it lightly using all the fine points I learned from the Guillow's Arrow.

The plan outline:  https://outerzone.co.uk/plan_details.asp?ID=3102

The free plan.  I still have the original plans and parts outline.  https://freercplans.com/plan-lil-roughneck-1791.htm

The video- Bruce Tharpe's rudder and throttle version.
https://www.youtube.com/watch?v=Prk6S_w_lDQ

Have started cutting parts.

Frank

[Frank v B]

Cut out the main fuselage parts.

[Frank v B]

Keep going...

Photo 32- Notice the bottom of the servo has come apart.
Photo 033- same servo, bottom closed, dental floss wrapped and glued.  It ain't coming apart again.
Photo 133 - the start of the fuselage
Photo 135- fuse sides joined
Photo 136- used 1/16 sq. stringers instead of 1/16" sheet. Bottom of the nose installed.

To save weight
- left out the fuse doubler on both sides.
- used 1/16" stringers on the turtle deck instead of 1/16" sheet.
- front fuse top is 1/32" instead of 1/16" on the plans.
- left out the fuse bottom sheeting behind the wing.  Just used 1/16" square sticks.
- will change the wing from 1/16" fully sheeted balsa top and bottom to a regular open structure with covering.

Frank

[octagon]

Looks good Frank. I like the planking on the turtle deck. Are you using CA on this plane?

[Frank v B]

Rob,

Yes, I am using CA and some 5 minute epoxy.  It is a bottle of thin CA that was given to me by John's Hobbies to use on the hinges for the 10cc Valiant.
Don't tell my wife.  Our house is a CA-free zone.... most of the time.

Frank

[Frank v B]

Fuse completed and sanded.  Weighs exactly 1 oz.

[Frank v B]

Wing.

Changed the design because it was heavy. 

The original design was  twelve widely spaced  1/16" ribs between a top and bottom 1/16" wing skins.  No trailing edge, no spars, only a 1/8" dowel for the leading edge.

Changed the design to a more standard two spar, trailing edge and 18 ribs and 3/16" square leading edge (rounded off).

The ribs had to be changed.  Picked a flat bottom rib from my collection of about 30 rib templates.

Installed a trailing edge, placed a bottom spar where it was located on the rib and then filled in all the other ribs.

Once this assembly has dried, I will tackle the leading edge.

Frank

[Frank v B]

Installed the leading edge.

This wing has a fair amount of dihedral...  a must to allow it to turn with only rudder and elevator. 
I build both halves together but the LE, TE, and both spars are cut in the middle.  Only 1 of the two center ribs was installed (right wing half). 
The left wing half center ribs is not installed.  This way I sand the proper angle into the spars until the proper dihedral is cut in, then make the center rib fit, then glue everything in place all at once when the dihedral is set.  This way setting the center rib angle is not critical and all spars and LE, TE are perfectly aligned.

Frank

[Frank v B]

The wing dried over dinner.

- Removed the left wing from the plan, sanded the angle into the 4 sticks (upper & lower spars, leading edge and trailing edge)
- cut the center rib to shape.
- clamped some scrap balsa to a rib and determined the 2.25" dihedral.
- glued everything.

Frank

[Frank v B]

All bones.  No skin.

next- have to figure out the landing gear.

Frank

[octagon]

looks really fun Frank. What motor will you use?

[Frank v B]

E-Flite 180 on 3 cells.  The one in the video on the first post is a 180 on 2 cells.

Frank

[Frank v B]

Figured out the landing gear.

- drilled holes in the spar and embedded a plastic tube inside a soft balsa sheer web.
- formed the landing gear and added a smaller tube onto the wire where it will insert into the larger (white) wing tube.

Note: the reason for the two tubes is mostly to add thickness to the wire so it spreads the loads.  Without them the wire will probably rip out on the first landing.

Two things about landing gear on tiny airplanes I learned from experience
1) undersize the wire.  This way half the landing impact is absorbed by the landing gear and the other half by the plane.  If the landing gear is too strong (thick) it will rip it out of the mounts.
2) Torque rods are better than coil springs to achieve the above.  A torque rod is where the permanent mount into the wing is offset from where the landing gear leg first touches the wing.


- glued in the rudder and elevator servos.

Frank

ps: The second photo shows that the rib was stolen from a 60% size Junior Falcon I built about 15 years ago.

[davidk]

I hope, in a few years, to understand (or at least pretend) some of this.

[Frank v B]

David, David,

I guess it may come across to you as computerspeak is to me.... the guy with the flip phone.   

Let's try this one. (DavidSpeak in parentheses)

- built the tail cone (ass end) of the fuse.  Made from 3 pieces of soft balsa on top of a 1/16" sheet to mimic the stab (horizontal ass-end wing).  Photo 80.
- sanded it smooth to follow the contour of the fuse. (made it fit in.) Photo 83.

- covered the plane with film in my inventory (put clothes on it from my closet!). Photo 84.

Next- final assembly

Sorry David. Couldn't resist.

Frank