ShankRC (AviationStation.net)

The material in the National Balsa short kit is of good quality.

I have a feeling these stringer notches are going to need deepened when the time comes.

The necks on these alignment tabs are entirely too small and there are too many of them. There were a dozen or so broken off when I received the kit as well as a few that I broke off separating the parts.

More broken tabs on the 1/32" plywood.

The front and rear spar joiner box sides should all be the same length. Not only are they not the same length, but none of them are the correct length.

The ribs at the aileron bay had no seat for the rear spars to keep them spaced properly. I've added one to all of the ribs similar to the one shown here.

Ribs and front shear webs in place. You can see the large amount of washout built into this wing.

Starting the tip construction.

Adding a light balsa filler piece to the top of the rear spar.

Filler piece sanded to the contour of the ribs. The front spar will get the same treatment.

Aileron ribs, hinge pin, and inner nyrod guide tube dry fit together.

I use 3/32" aircraft ply for the hinges in lieu of the formica that the plans call for. I guess I can't fault National Balsa for this one since Wendell calls for formica.

I epoxied a small ply reinforcing plate on the inner rib where the hinge pin will end.

3/32" aircraft ply control horns cut out on the scroll saw. Again, the plans call for formica but I feel that these should have been included with the short kit.

All jig tabs made up and ready to glue up the aileron.

It was decided to go with concealed linkages on the ailerons so I've removed the little ply plate reinforcement and added a new hinge location that will allow room for a torque rod setup. The plywood control horn will be removed later.

aileron trailing edge added.

The area of the top rear spar with the pencil scribbles has to be carved/sanded down to form the wingtip.

Enough top sheeting on to pull it off the table and inspect things underneath.

Top sheeting completed and rough sanded.

1/16" plywood shear webs sized to fit.

Plywood shear webs glued in place in the two rib bays beyond the spar joiner boxes.

Mounting blocks epoxied in place and then filleted with a mixture of epoxy and milled fiberglass.

Top view of mounting blocks prior to sanding flush with the top wing sheeting.

1/16" music wire hinge pin bent to final shape and notched into the wingtip.

Hinge pin inserted all the way into the wingtip notch.

First piece of sheeting glued in place.

In order to "pin" the spar joiners in place, I have to install them now before completing the bottom sheeting. The joiners are epoxied in place and then...

Birch dowels rough cut to length until the epoxy cures.

Dowels sanded flush to the joiner box.

Ribs are notched out to allow the torque rod assembly to drop in place.

I chose to use the square tube for the bearing tube in order to get a more positive lock in the plywood ribs.

Square tube soldered to torque rod to make up the plug-in feature.

For added security I've drilled a 3/32" hole and inserted a tube through the soldered tube.

The hinge pin stops short of the end of the aileron to make room for the torque rod.

I've cut a 1/8"x1/4" notch in the ribs for a spruce stringer.

A few epoxy/milled fiberglass bridges over the hinge tube to ensure they don't break loose from the CA glue.

The aileron leading edge is sheeted with 1/8" balsa. To make things easier I am using 2 layers of 1/16" balsa.

I made a balsa straight edge jig to check and make sure that the hinge pin is straight throughout the length of the aileron.

Aileron clamped back in position to re-glue the nyrod hinge bearings.

A little black Sharpie on the end of the nyrod bearing will transfer a mark to....

... the back of the 1/32" ply end cap to locate the hole properly.

I have added stiffeners to all of the rib jig tabs to help ensure they don't break off if I put too much pressure on the wing at any time.

Left wing panel framed up.

The aileron ribs and their associated jig tabs have been dry fit in place.

A lot of steps done to the left aileron here but the end result is that I have a better understanding of what went wrong with the right aileron. I had traced out a set of aileron ribs prior to gluing up the left side so that I can rebuild the right side properly.

Gathering parts to rebuild the right aileron. I will tear apart the original one and use the torque block and spruce spar...everything else gets trashed.

Hopefully the third time is the charm.

Much better...I am finally happy with the right aileron and can move on.

Now to take care of the fact that the aileron leading edge binds on the wing trailing edge. Simple fix of trimming the ribs a bit before sheeting.

The aileron leading edge tips are a pretty small radius to be sheeting so I filled the end in with solid balsa...

...and carved / sanded to shape.

Gathering material for the aileron gap shrouds. They will be made from laminated 1/32" plywood and 3/32" balsa to match the 1/8" wing sheeting.

I drew a line about 1/4" back from one edge to help keep the taper consistant.

Aileron put in place to check for a consistent gap. I did some sanding to the aileron leading edge to get to this point.

Shot of the wing trailing edge with both the top and bottom shroud in place.

The plans clearly call for 1/32" plywood end caps on the wing panels so they should have been included in the National Balsa short kit but they were not. I've used a W-1 rib to lay out a piece that will span the 2 spar joiners and will finish off the front and back with scrap..

1/32" root end cap in place.

I guess the S-2 rib didn't need cut at the hinge line...not at all impressed with National Balsa's short kit.

Setting the stab aside for a bit to start working on the fuselage. Modifying the Hostetler drawings to extend the tail for the R1/2 version.

Matching top and bottom cross pieces all cut and ready to go.

Main fuse box of this beast taking shape.

Shot of the rear of the firewall. There will be triangle stock added later to reinforce the glue joint to the fuse sides.

Former F-2 added.

Hatch formers at F-2 and F-3 cut and clamped in place. These formers were missing from the National Balsa short kit.

I was out of 1/8"x1/2" stick material so I made a quick balsa stripper. This little gadget turns a 1/8"x6" sheet into 12 strips in about a minute.

Transferring the Hostetler stringer locations to the Haffke former shapes proved to be futile. I ended up having to sight the stringers individually and re-cut slots as needed to straighten them up.

The new former F-7 in place.

Stringer slot being re-cut and shimmed with 1/16" balsa.

Former cut out for the wing joiner box.

A shot with the wing outer panels in place. For size reference, the workbench is a 36"x80" door panel.

Filling in the remaining stringers around the wing joiner boxes.

...when i make the cutouts for the spar boxes.

Stub wing ribs in place.

Left side top sheeting completed.

Both stub wings completed to the point of sheeting the tops.

4-40 SHCS will be used to mount the gear...6 per leg.

4/40 blind nuts used on the underside.

It's necessary to keep the gear mounted while gluing the plates in place so everything lines up properly.

Shot of the front leg mounting.

Shot of the completed gear mounting.

Outer wing panel in place.

The side rails that will make up the hatch split are glued in place and shaped/sanded.

1" triangle stock epoxied to the firewall and plywood fuse sides. There will be matching ones on the inside later.

I have decided to strip plank the front end because of the compound curve to the firewall. First two planks glued in place along the bottom center stringer.

More planking glued in place. I experimented with a few gluing methods and found that using yellow glue on the edges and thick CA on the formers to work the best.

I popped the hatch out just to make sure it wasn't glued in place. The hatch will be put back in place for final sanding/shaping.

Starting to add the former tops and stringers.

Adding to former F-6.

Just getting a feel for where the canopy will sit and marking out some layout lines.

Fin leading edge in place. There is quite a cavernous space here now with the extended tail so I will have to add a little structure in there later.

Right side stringers in place.

First former in place.

Turtle deck / fin planking in place. Two of the planks didn't want to make the transition from horizontal to vertical so they were pieced in. The gap will be filled with balsa and sanded to shape later.

Sheeting between formers 3 and 4.

The false former and firewall blocking is completed.

Rear turtledeck / cockpit planking completed and rough sanded.

Thin coat of filler applied to the rear planking.

Stab cutouts extended through the outer sheeting.

Modifying the stab core to more of a scale outline.

The elevator cores have been trimmed square and then a piece added to make up the shape of the R1-2 elevators.

New elevator shape.

Hinge points installed into the stab trailing edge.

Stab ribs glued in place on the top side of the plywood core.

Another shot of the stab test fit.

Right side elevator ribs glued in place and sanded to shape. The basswood block will accept the elevator torque rod.

Laying out the rounded leading edge. The elevators were built tight to the stab so there will be 1/8" of material removed to create a hinge gap.

Marking center lines to use as a guide while carving/sanding the leading edge to shape.

The original R-2 rudder core laid on top of the tracing for the R1-2 rudder.

I want to use the original core so I will have to add some 1/8" plywood to make up the difference.

Drawing out the rudder hinges.

Hinges cut out and trial fit to the 1/8" plywood tailpost.

Inner nyrod glued to the leading edge of the rudder core for the hinge pin guide tube.

Upper tailpost set in place with the rudder core attached.

Lower plywood tailpost.

All four rudder hinges in place on the upper and lower tailposts. The split is for the stabilizer trailing edge to pass through.

Rudder hinge alignment is complete...time to build this massive rudder.

Rough shaped rudder ribs glued in place and squared against the tailpost. I am hoping to leave these in place until the bulk of the rudder sheeting is completed. Otherwise, I'm not quite sure how to sheet the rudder without twisting it.

Left side of the rudder ribs and leading edge shaped.

Bottom left side of the rudder.

Time to lay out the position of the rudder control horn and get the servos in place.

Drawing out the rudder servo tray.

Servo rails are pinned with toothpicks and filleted with epoxy / milled fiberglass.

Trial fit of everything in place inside the fuselage.

Control horn cut out of 1/8" plywood. I am setting this up with a solid pushrod pull/pull at this time but may change it to pull/pull cables later.

Slot cut into rudder core to accept the control horn.

1/4" basswood triangle stock epoxied on all four sides of the control horn will make sure it stays in place.

Because the rudder has been enlarged considerably, I am adding another rib mid way out to stiffen up the sheeting a bit.

Laying out servo locations in the horizontal stabilizer core.

Basswood epoxied to the top of the stab core for servo screws.

Right side shrouds in place.

With the shrouds completed and leading edge rough shaped, the stabilizer is ready to be permanently mounted to the fuselage.