If you are looking for some detail drawings to build the inside of your J-3 take a look at this pdf file. j3inside.pdf The drawings are based up on full scale prints. Where I did not have prints, I was able to scale the parts using other 3-views and photos. Please note that you will need to make modifications for the items to fit in your Cub. Prints are for 1/4 Scale, when printing check that they are printed out 1 to 1.
Dynamic Balsa & Hobby Supply has a nice vacuumed formed interior kit for the 1/4 scale Cub. This is a good, for a quick install. The quality of the kit I got was great, it contained several sheets of parts that include, seats, foot pedals, kick plats, throttle panels, fuel cutoff, instrument panel, control yoke, and a few other small parts. A few instruction and a few drawings accompany the kit. I bought one but after a few years of use, I wanted to go to a little more detailed look.
For all Nomenclature and place cards check out Decal-It for them Most of the Cub nomenclature can be done with stencils if one wants to paint or will be able to offer them in decals or water slides.
As I have stated in other articles please read through the article before starting. The colors and details I have used are for the plane I modeled after. The details on the plane you are modeling may not match what is on the plane I’m modeling.
Preparing the cabin.
I cut a panel from 1/32 balsa one to fit each side to give me a solid surface to use. I then covered it with cloth covering and painted. It is recommended to trace openings where the carb heater and fuel shutoff is located. Glue the panels into the cabin, and hollow out the openings for the carb heat and fuel shut off to allow the panels to recess in to the wall. For the floor, the section is cut from 1/16-ply. Temporary fit them into the cabin and keep trimming until you have a good fit. Insert two toothpicks into the fire wall just above the floor, and all them to extend into the cabin area about 1/8 inch The front floor board should fit under the toothpicks, secure the back of the front floor board with a screw in each corner. For the back floor board it will be attached with a screw in each corner. You may need to add blocks to screw into. Paint the floor boards flat black.
Recommend taking a rectangle of card stock and keep trimming it until you have a good fitting instrument panel. Now transfer this to a thin sheet of plastic. I have seen both a flat panel and a panel that the top curve forward. Next cut holes for you instruments, you will want to cut the holes just a hair larger than the instrument. Next painted your panel with flat black spray paint. Flat black is used on full scale so that the sun will not reflect off the surface and blind the pilot
Next take a section of 1/32 or 1/16 ply and cut a rectangles that will fit behind the instrument gauges. This rectangle should extend on all sides of the gauges buy 1/4 inch. You will also need a strip of clear plastic to match the ply. Copy the instrument panel from the manual and glue it to the section of ply. Next apply a sheet of thin clear plastic to the top of the gauges. Place this behind the instrument panel and use small screws available from Micro Fasteners to fasten it all together. Four screws to each instrument, one in each corner. Do not use CA as it will fog the clear plastic.
Apply other details to the panel including nomenclature, switches, knobs, and pulls. If you want to make it stand out, make small rims to go around the gauges.
Seats and Seat Belts
You may need to narrow the seats to fit your Cub, The seats can be made simple as balsa, painted black or they can be made from vinyl. I covered the seats with a thin black vinyl material from a craft store. Vinyl will require a little more work The seat back and bottom are made from 1/16 ply. Use some batting and fill the seats giving them some form. The front seat frame is made from 1/16 dowels. The back seat will be mounted to two 1/8 dowels that span the width of the cabin. I have seen both round and flat top seat in the back of the cub so.
Seat belts are made from a 1/2 inch woven black ribbon from the craft store. The weave in the ribbon looks like a real seat belt. For the buckle you have two options. Option A is to buy two cat collars that snap together and used them. Option B is to build the buckles as outlined in the article in Submitted ideas section.
Throttle panels are triangle shaped. Trim two throttle panels from sheet of thin plastic and paint flat black. Apply text to panels and spray a coat of clear acrylic on the parts. To make the throttle lever, I bought a pack of wood balls about 5/16 diameter at a local craft store. Cut a small flat slot in the ball like you would see for a flat headed screw. Take a strip of 3/16 wide sheet metal 1 inch long, and bend the first 5/16 over and make an L shape. Glue the ball on to the 5/16 section of the L and paint black. Drill a small hole at the bottom of the long section and screw to the side of the cabin. It is recommended to recess the leavers into the side of the cabin. Now screw the throttle panel in place with three small screws, two on top and one on bottom.
Fuel cutoff and Cabin heat
They are round on one end and flat on the other. You will need to press form the panels and trim as needed. Paint with flat black, apply text to panels and spray a coat of clear acrylic on the parts. For the Fuel Cutoff I used a strait pen with a 3/16 ball head on it painted silver. The Cabin heat is silver flat circle with a black C in the center on a straight pin. You will need to recess the area where the panels are to go. Mount the panels with small screws and insert the pins in place.
Rudder pedals are made from 3/16 dowel. For the upright sections you will need to grind a U shape into the top and bottom so that it will be recessed to allow the top and bottom section to fit snug. Dry fit the parts by attaching the short section on top and bottom of the U cut on the upright section making a I shape. If you have a good fit apply a little glue and let dry. You will need a total of four. For looks mix up a little five-min. epoxy and using a toothpick apply a bead of epoxy around the joint on the I, you are trying to mock a weld joint. Paint black when done. On the back two pedals drill a 1/16 hole through the end of the T, and on the front two drill it only half way through. Cut two strips of pull pull wire long enough to run from the front pedals back under the back seat. Glue the cables to the front pedals. Attach to the floor by gluing the pedals to the bottom of the floor board.
The trim panel is made from a square of plastic (.015 thick). Cut out the long grove on top. I applied a small section of electrical tape to my cutting board. Paint the panel flat black. Apply lettering and spray with a clear coat.
Now for the handle. For the base I cut a section of 5/16 dowel about 5/16 long. Drill a hole in the center to allow a 2-56-thread rod to screw in. Next cut a circle of 1/32 ply into a 1/2 inch circle. Drill a hole in center and thread it on to the 2-56 rod. What you have now is a section of dowel setting on top of a ply circle with a thread rod protruding the bottom. Mix up a little 5-min. epoxy; apply as you rotate the part in your finger to form a nice fillet around the part. For the long part mount a 2-inch section of dowel in a drill. Sand the end of the dowel round as it turns in the drill. Now from that point down about 7/8-inch turn it to look like a bat. The end part should be turned down to about 3/16-inch. When done sand with fine sandpaper for a slick finish. Cut the handle off at 7/8-inch long. For the round end you will need to cut down the center for 5/16-of an inch and remove it. This will allow it to be glued to the previous part made. Some final trimming may be required for good fit, glue when ready. Now cut a 3/16 section of outer golden rod and glue in place to the knob end of the handle. The knob is turned from a section of 3/16-dowel. As done above apply some 5 min. epoxy to form fillets where needed. Paint as needed.
Apply plate to wall and trace opening for trim indictor. Remove plat and paint traced area flat black. Reapply plat and attach with screws. For the trim indicator a trim the head of a small nail into a triangle shape. Paint and applied in the indicator slot. Drill the center of the plate (where handle attaches) to accept a section of inner golden rod. Cut small section of inner rod and glue in hole. Now screw the handle on and you are done.
Kick plates can be made from squares of thin aluminum sheets. Extra detail can be added by very lightly spraying the panels with a mist of dirty brown, after dry come back with 600 grit sandpaper and remove the paint in the center sections making it look like your feet have rubbed it.
Make from 1/8 dowel, the flat part of the pedals is made from thin plastic. As with rudder pedals make a U shape to accept the cross members. Paint and attach to the floor boards.
The control sticks are made from 1/4 dowel, and the bottom section of the yoke is made from 5/16 dowel. All other parts are made from hard balsa. Assemble and paint flat black.
Install the instrument panel with 4 screws to the cabin. The front floor boards needs the rudder pedals and brake pedals attached. This is now ready to be installed. The back floor boards needs the rudder pedals and brake pedals attached. Next attach the control yoke to the floor board. You will want to attach a 1/16 black dowel to the back of the control yoke and allow it to extend back under the back seat. Install the front seat onto the back floor board and finish with attaching the kick plates with a screw in each. The back floor panel is now ready to install. Install the back seat by attaching the 1/8 dowels to the cabin sides.
The area behind the back seat has a curve to it and wraps around the back seat. Make this section from 1/6 balsa. You may need to wet the balsa to help bend into shape. Cover and paint to match the inside. Next just below the window line, install the deck behind the seat by using 1/6 balsa. In the center make a fake hatch out of 1/16 ply and clear coat it. Add any other details you want.
Full scale cabin