Thunder Tiger Piper J3 Cub: A new take on a classic favorite

Model Airplane News, Jun 2001 by Palmer, Keith

MODEL AIRPLANE NEWS

FIELD & BENCH

REVIEW

A new take on a classic favorite

The Piper J3 Cub has long been a favorite airplane of modelers, whether in free-flight, control line, or radio-controlled form. Nothing else flies like a Cub, and practically every model manufacturer has a Cub of some sort in its inventory of airplanes. Thunder Tiger's latest is the 82-inch, IMAA-legal Piper J3 Cub, but make no mistake-this absolute blast to fly and-as you would expect from Thunder Tiger-this model is of excellent quality from nose to tail. What you might not expect is the level of scale detail that this ARF incorporates; with a little dressing up, this big Cub can get you into the winners' circle at your next scale contest.

KIT CONTENTS

The kit was delivered to me at the flying field, so I decided to open it there to get impressions from my flying buddies to add to my own. We opened the box and were greeted by a bright yellow Cub with all of the copmonents and was pleased to find that only a radio, engine and glue were needed to complete the airplane. The scale-looking landing gear is prebuilt and chrome-plated, and the wing struts are made from hard wood that has been airfoiled and notched to accept the mounting plates. We were all impressed with the covering job, as well; there was no sign of dust or debris between the covering and the airframe as I've seen with some other ARFs, and everything fit together nicely. If we'd had some CA and epoxy on hand, I think we could have built it at the field.

CONSTRUCTION

The kit includess a very nice 23-page instruction book that is filled with photographs. After thumbing through it, I estimated that I could have the Cub in the air in fewer than 10 hours, so I set off to work. The first step is to hinge the ailerons to the wings with the already cut into all of the movable surfaces, so this step took just 45 minutes, and 30 of that was drying time. The next step is to cut away the covering material from the servo bays and the aileron wire exit holes. The aileron servos are mounted on their sides, and the grommets fit between the preinstalled hardwood mounting blocks. Screw the nylon strap into place over servo to hold it securely. Extension wires are needed for the servo leads, and the kit supplies heat-shrink tubing to put over the connections. Use a piece of piano wire to fish the extension wires through the wing. Screw down the servo hatch covers with the servo output arms extending through the slots in the covers. Then screw the supplied control horns into place on the ailerons and use a short pushrod wire to connect the aileron to the servos.

The wing halves are held together by a joiner that is composed ofa piece of aluminum sandwhiced between two pieces of plywood. The first step is to glue the ply to the aluminum piece using 30minute epoxy and plenty of clamps. When the glue has dried, remove the clamps, draw a centerline on the joiner and dry-fit it into the spar box to make sure that it will go all the way into each wing half. When you're sure the fit is right, glue the joiner into one wing half and then the other, and join the halves as they come together using slow-curing epoxy. Hide the seam with the supplied yellow trim tape. Then glue the hardwood wing-bolt plate into place on the top of the trailing edge after removing the covering from where it will be glued. The holes for the wing bolts are already in the plate, so all that is left to do is to transfer the holes through the wing using the bolt plate as a guide. Two installed 1/4-inch dowels position the front of the wing to the fuselage. The one problem I had with the wing was that the cutout in the wing leading-edge center was not wide enough to fit over the front of the fuselage windscreen. I had to sand about 1/32 inch off each side of the opening to make it fit. The 1/4-20 blind mounting nuts are also pre-installed in the fuselage for the wing hold-down bolts. I was quite impressed with the alignment of the kit; everything lined up without any problems.

The fuselage is almost as simple as the wing to construct. First you need to remove the covering material from the openings where the stabilizer, fin and landing gear will go. The covering must also be removed from the pushrod exits. Use the supplied retainers and screws to hold the landing gear to the fuselage, and mount the scale wheels and landing-gear fairings to the landing gear just as the instructions describe.

Next, add the tail feathers. Start by joining the two elevators using the supplied wire joiner and thick CA. Next, hinge the elevators to the stabilizer using the supplied pinned hinges and 30-minute epoxy. With the wing bolted to the fuselage, I centered the stab in the fuselage and drew a line on each side of the stab so that I knew where to remove the covering. After making sure that the stab was parallel to the wing, I glued it in using 30-minute epoxy. I used the same procedure to mount the fin and rudder, except that the tailwheel wire must be glued into the rudder before hinging. I was very impressed with the fit of the stab and fin; the stab required no adjustment to make it parallel to the wing, and the fin was 90 degrees to the stab without adjustment.