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        Build Log Cartoon C-119

#1 davidterrell80 Aug 01, 2012 01:47 PM

Cartoon C-119
 
7 Attachment(s)
This is my first build log. So please, be gentle.

Back in 1963, I received several toy airplanes as Christmas presents. Among them was a toy C-119. Finding the photograph in my late father's Navy footlocker, I became tempted to make a cartoon RC out of the idea, based on my memories.

I do not remember what happened to the plane but, I remembered that the fuselage was an dark blue plastic and the wings and booms were silver. I wondered if I could build something around the PZ UM Mosquito brick, motors and props, keeping the weight down to overcome the added drag... or would something in the 180-size be necessary? I started making some sketches from the photo and recording some thought on a blog thread.

Then, I decided to go looking for information on the toy. found the same toy at the "National Museum of Play Online Collections" C-184-10 / U.S. Army Globemaster / Flying Boxcar

I also found an antique toy trader with a example of the toy.
http://www.txantiquemall.com/ttm_vintoys.htm
US Army Transport C-184-10
Materials: Metal & Plastic, Decals on Both Engine Mounts/Tail
Size: Wing Span: 22"; Nose to Tail: 17"
Condition: Played With, Split to Plastic on Nose & Tail

Interestingly, he was located less than 80 miles from where I grew up (Conroe, Texas) so, conceivably, he might have my toy.

I wanted it back! So, I bought it!

I received the prototype toy... and, it was spooky. I thought to myself, "I remember it being bigger." I suppose to a 5-year old it was huge.

I sat down and measured the airframe. Then, I began laying out a top view drawing. I can tell that the big challenge will be the main fuselage. The compound contours cry out for a vacuum molded shell but, I don't have the equipment. I could "make do" using the luan plywood, George Foreman grilling machine, and shop vac... and I may yet.

I finished the main portion of the drawing... lacking only a thorough treatment of the fuselage.

So... let us look to where we are going, never forgetting where we have been. With all of our errors showing, let us begin.
Hi, Ho, Silver! AWAY!

David

#2 davidterrell80 Aug 01, 2012 01:48 PM

CONSTRUCTION THOUGHTS

Controls
-- The AR6400T has the rudder and elevator servo integrated in the board. perhaps I should plan to put the board in one boom, aft of a motor, over or behind the wing. Then, I can run the elevator and rudder control linkages aft, through the boom to the tail surfaces. This, in turn, would allow me to control the elevator from one end, so the surface needs to be relatively stiff and perhaps balanced. For the rudders, I can use a pitch horn on one and use a linkage to reach across to the other side. Again, stiffness will be important. perhaps, a trailing edge carbon rod linking the two. The aileron servo could easily be in the opposite boom and I would use a single aileron, full-span on the outboard section. If the single surface proves insufficient, I can run a long rod to the opposite wing for a second aileron.

Fuselage
-- I could use a balsa or foam in a form and stringer approach to the fuselage and cover it with a material like aerolite.
-- As to any lateral CG issues, the fat fuselage gives me plenty of room to shift something to balance laterally.
-- Battery placement and construction. I'm thinking of incorporating a parting line in the fuselage at the waterline marked by the base of the wing. The entire assembly of wing, booms and enpennage would lift off the lower fuselage and I could then attach the battery to the underside of the wing as needed for balance, both side-to-side and fore-and-aft. In fact, I could build the wing, booms, and enpennage as a single structural unit; building a separate fuselage to attach to it.

#3 cracksmeup Aug 01, 2012 08:35 PM

Alright david I think this would be fun to watch iam sighned up . :D Joe :popcorn:

#4 Aero Andy Aug 01, 2012 11:03 PM

I'm here too David, looking forward to following the build. :)
Andy

#5 davidterrell80 Aug 02, 2012 10:14 PM

I have patterns made for everything but the fuselage. I'm planning to cut a first set tomorrow and, perhaps, assemble them up to check the fit. For simplicity, I'm thinking about using a single aileron on AC-1

#6 cracksmeup Aug 02, 2012 10:20 PM

Quote:

Originally Posted by davidterrell80 (Post 22341572)
I have patterns made for everything but the fuselage. I'm planning to cut a first set tomorrow and, perhaps, assemble them up to check the fit. For simplicity, I'm thinking about using a single aileron on AC-1

I like it when the glue starts flying david cant wait to see what you have come up with .joe:D

#7 davidterrell80 Aug 03, 2012 03:44 PM

while the drafting supplies were out, I thought to go ahead and finish drafting the fuselage plan. I chose to go with a profile, some frames, a few doublers, and shaped skin; all made from MPF foam. Then I estimated the weight. It looks like this.

Fuselage-31.2 g
flying surfaces and the booms-35.9 g
that puts the dry airframe at just over 67 g or 2.4 ounce

two motors, e-flight 180 Park with connectors and shaft keeper-23.2 g
receiver-4.6 g
two speed controllers with connectors-23.6 g
a Y connector for the controller-4.6 g
a hefty 7.4 V 800 mAh battery-43.4 g
three, 5 g servos (because I have them)-15.3 g
figure in 20 g for pitch horns, wire, glue

the job totals up to about 136 g. So altogether, I'm looking at about 204 g or 7.2 ounces.

With the two motors I'm planning, it should have almost 3-D performance.
Dad gum it! This thing will fly, even if I have to make it hang on the props.

If nothing else, I'll scale it up 30% and transfer the components to a larger airframe.

#8 cracksmeup Aug 03, 2012 04:16 PM

Sounds like a plane i would like to fly. :D joe

#9 davidterrell80 Aug 03, 2012 10:14 PM

2 Attachment(s)
Got a set of the booms and surfaces cut. Booms are glued but nothing is sanded.

#10 davidterrell80 Aug 06, 2012 07:45 PM

11 Attachment(s)
I have the central fuselage pieced together. As I suspected the nose section, with its compound contours will be the stinker. I've made two starts on it thus far, only to have them fail. I'm beginning to think a silicone cast of the interior to build a male layup plug will be the eventual way to go. Unfortunately, my staycation ends tonight and my ability to spend time on the plane will be much reduced.

#11 IWC Aug 06, 2012 08:39 PM

sub

#12 cracksmeup Aug 07, 2012 08:31 AM

I have seen ,i think his name is tam cut slits in the foam taking some out kinda like a long v and then gluing it back together to make the compound curve's .Iam trying to find his thread so i can show you how its done. This is not the thread i was looking for but you can get the idea of how to make the curved /round nose.http://www.rcgroups.com/forums/showthread.php?t=1403481 joe

#13 davidterrell80 Aug 07, 2012 09:14 PM

I appreciate the references and the encouragement.

I've thought about flat-patterning the nose and make it up using using thinner foam. I have the skills to draft it out and, if I want, I have TurboCad19 now.

I was trying to rush... being lazy... hoping to finish before my vacation ended.

I have some thin foam. Tomorrow, I'll take some and make an effort.

#14 cracksmeup Aug 07, 2012 09:35 PM

I have tried to cheat with foam and bending full pieces of balsa to make up compound curves when building balsa neccels on planes but i always end up back planking them with strips and sanding them to shape . If i would just planked them to begin with i would have not wasting any time. Will i try cheating again,probobly :eek:,iam hard headed sometimes at trying to do somthing new.:D I like your build so far david ,alot of thought has gone into the framework of the fuse and it looks good.:D joe

#15 davidterrell80 Aug 11, 2012 12:02 PM

4 Attachment(s)
Ok!

I made great progress.
I successfully made up the nose section, using some Dollar Tree 5mm foam for the skin.
I've assembled the fuselage. It still needs spackling and final sanding.


So here is the way ahead...

1. Fuselage: Spackle and sand. A thin coat of WBPU to toughen up the skin. Add the wheel attach points. Color her blue and color the windows and radome. Fabricate and add the wheels. Cut the wing saddle/hatch out of the upper fuselage and place magnets to hold it on.
2. Wing: Add a CF spar. Cut, hinge & horn an aileron. Color the wing.
3. Elevator & Rudder: Cut, hinge, horn & color.
4. Booms. Sand, color and attach to wing, placing horiz stab and aligning all.
5. Fins: Attach to the booms. Align and interconnect the rudders.
6. Servos: Elevator and Rudder are inset into underside of wing at booms. Decide if Aileron servo should be in fuse or in boom.
7. Rx & ESCs installation in fuselage.
8. Motor and cowl.


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