R/C Red Hawk Project into F16 Card Model

[mbauer]

A friend at work bought this small 3-channel RC airplane. He has crashed it several times replacing the parts as needed. His last attempt at eating a chain-link fence ended up looking like this! The wings were completely shredded.

The RC parts survived, the plane can be rebuilt for around $30 USD.

Red Hawk Specifications:
Wingspan: 41"(1041mm)
Length: 28.5" (723.9mm)
Fly Weight: 16.9oz (479.11gm)

RC F16 Card Model Specs:
Wingspan 21" (533.4mm)
Length: 36" (914.4mm)
Weight: 15.8oz (447.92gm)
Range: 500' (152.4m)

He gave me the parts to adapt them to a card model.

This thread is about converting foam/plastic to cardstock.

It will show some of the techniques I've learned/used to create big models that fly!

Best regards,
Mike Bauer

BTW-I'm in the process of moving to a new place (already here just need to get moved in...i.e.;Find my cutting tools!!)

[mbauer]

My answer to mounting the parts from the Red Hawk.

Cardstock used is International Paper's Springhill Tag 125#. Equivelant would be Springhill Index 110#.

The motor itself is mounted just like in the plastic model. 6-pieces of laminated cardstock easily handle the job of mounting the motor using the screws provided by the Red Hawk. Notice the half-moon shape cooling air flow holes. (changed while building from the small holes around the perimeter).

Inside there is an additional lamination of 4-pieces of cardstock around the motor. This stabilizes the motor and makes the tailcone extremely strong!

Battery tray will have one wrap of 1" (25.4mm) wide cardstock glued solid.

Servos are mounted on the plastic frame supplied by the Red Hawk. More photos later of control line(pushrods=fishing line) from servos to Elevons.

[mbauer]

Servos are mounted on the plastic frame supplied by the Red Hawk. More photos later of control line(pushrods=fishing line) from servos to Elevons.

Notice fuselage piece under everything!

[mbauer]

Notice "Fanfold" wingspar? Next Photos show these in action!

Bag of goodies, soon to be used! More parts supplied by Red Hawk!

[mbauer]

Wing construction using ribs/spars.

Double ribs allow tabs on both sides to help glue wing skin to rib equally (helps stop warping)

[mbauer]

When gluing skin to internal structure, start at tip and then work towards wing root! Must keep strecthing the skin tight to trailing edge, while gluing!

[mbauer]

Wings Ready to Mount to Fuselage!

Elevons are also done! Elevons are made from 6-total laminates of 125# cardstock. The center 2 laminates are the only ones that are complete. The other laminates are cut where the actual control surface is needed. You can see this on the left Elevon. The center laminates are used as the hinge! THe final laminates actually cover the rest and give it the airfoil shape.

[mbauer]

Rolling/Gluing the fuselage.

I use the chair and table top as "bridge" foundation for some wood dowel. On the dowel are wraps (bands) of double stick tape placed about 3" (75mm) intervals. This holds the fuselage for gluing and yet allows it to "pop" right off when done.

One wrapping session will last many, many models!

Outside fuselage skin is done, internal section is being glued! Lines on internal section are for the internal formers (bulkheads). Wingspars will penetrate thru both walls of fuselage. Lots of glue points = strong model!!!

[mbauer]

Photo of Inside View of Fuselage:
-Double wall fuselage design
-Wingspars
-Rudder Support (vertical cardstock in rear of photo-hazy looking)

[paul a]

got to love it another RC card model. it looks great excellent job!

[mbauer]

Fuselage ready for mounting of wings. Notice spar holes have been cut, they go thru both skin and internal fuselage pieces. Biggest opening is to allow gluing of the internal fuselage former.

Rudder internal support system is installed!

Notice how the motor attachment system fits nice and snug? Slides on and off, using velcro to hold in place during flight!

[mbauer]

Starting to align and insert the glue tabs.

Once inserted for test fit, slide slightly out and glue each side of the spars. Slide in and then hold while spars set. MAKING SURE TO KEEP THE WING LEVEL! as the glue sets.

Once the spars are in the next step is to glue the tabs.

Once both wings have been attached, the final step is to glue the wingspars from the right and left wings together. (harder than it sounds). Had to make a special tool to reach inside and use as a back-up while applying pressure with a wood dowel!

[mbauer]

Next is gluing side rail to fuselage.

Once this is done the Elevons are mounted to the side rail and also to the fuselage as well.

[mbauer]

Model Completed to this point. Moving to a larger apartment has interuppted the construction. Can't find anything!!! Better packing the next time!!

Still need to:
-Glue in Servo tray/Hook up control "rods" to Elevon/Servos
-Finish removable nosecone
-Weight balance (determine battery tray location)
-Wire the motor to the battery
-Charge the thing up and go fly it!

[mbauer]

All of the parts on the scale plus the trim and an allowance for the glue (extra cardstock added to the pile).

Looks like the card model is 1 ounce (28gm) less than the store bought foam so far.

Hopefully it will be up and flying by next weekend! Have to go thru some more boxes to find all of the stuff!

Mike Bauer