Late last spring two things I have been planning for a very long time came together.   I have been wanting to build the James Mears designed Raunchy Combat model since I saw the design in Model Airplane News in the 1960s.  I have been wanting to build a Vintage Performance Model Airplanes kit since Stan Fronabarger started the business over 10 years ago.  The two things came together when I traded Stan a pristine First-Generation Fox Rocket redhead .35 for one of his Raunchy kits.  The following details the build.

The Original

The Kit

Construction

This is the assembly of the basic wing frame. Note that I mangled the front of one of the wing ribs where the bladder tube goes through it.  Fortunately, the center section planking covered that up.  This seems like it should be a simple step, but I always manage to make a mess of it.

Once the wing structure was completed, I installed the wingtips, tip weight, and control system.  I’m paranoid about these things so while the tips were glued in place using thin cyanoacrylate, the bellcrank platform, leadout guides, and tip weight were all installed with generous amounts of five-minute epoxy.  The kit comes with a nylon bellcrank in which the pushrod hole nearest the pivot provides way too much pushrod movement.  When using these bellcranks I always drill a new pushrod hole 3/8” from the center of the pivot.  A bit of old guy advice here.  The way a Combat model flies is more in how the control system is set up and how the model is balanced than any other things.  Back in the day these models were usually designed with limited bellcrank travel and too much elevator travel along with being nose-heavy.  The excessive control movement required to overcome the forward center of gravity made them turn tight but slow excessively. 


This is my method for making perfect joints on center section planking.  I tape the two pieces together using scotch tape.  I then turn the parts over and run thin C/A over the joint.  When you turn it over and peel off the tape you find a perfect joint with no sanding needed.


This is my method for adhering the bottom planking to the ribs.  I put gap filling C/A the edges of the planking.  I then carefully position the planking and tape the edges to the trailing edge planking and spars.  I then flip the wing over and use thin C/A to attach the planking to the ribs.


This is my method for making pushrod holes in the planking.  I carefully locate the pushrod exit point.  I then drill a 1/8” hole at that location.  I then rotate the drill toward the rear of the planking making a slot with a radius in front of the hole on the bottom side of the planking and on the rear of the hole on the top of the planking.  This makes a super clean hole that doubles as a pushrod guide.  I now use my small cordless Dremel tool for this but I’ve used both a normal Dremel tool and a cordless drill for this job in the past.


I went old school to attach the top planking.  I used Titebond on the ribs and on the front a rear of the planking sheet using my Scotch tape method at the front and rear joints.  I made marks on the front and rear of the planking sheet at the location of each rib then used a 6” ruler to locate the pins in the middle of the sheeting to ensure a good joint.  The small pieces at the front were then installed using gap filling C/A.


My current favorite method of covering vintage Combat models is to start with Pelon Featherweight Fuseable interfacing.  I sprayed it with water then ironed it on with a very hot iron and finished using a Monokote heat gun to shrink out any wrinkles.

This is then covered with clear laminating film for fuel proofing and gloss.


I made a fixture for drilling holes in the elevator for the U-shaped hinge pins using 1/8” plywood and some heavy walled 1/8” copper tubing.


The final step is to cut grooves in the leading edge of the elevator using a V shaped Xacto gouge.  Or you can just cut a 1/16” flat.  A bit of thin C/A will hold the pins in place with no need of any reinforcement using the U-shaped hinge pins.


I don’t do engine mounts at all in the traditional way.  I use a 1/8” plywood doubler to replace the traditional balsa cheek cowl and add hardwood spacers to move the engine clear of that plywood.  I don’t glue that assembly on until the rest of the model is otherwise finished so I can adjust the engine position as needed and drill accurate engine mounting holes in a drill press.  When the holes are drilled, and the mount is completely finished, I slide it in place with generous amounts of epoxy on all of the mating surfaces.  The final steps are to drill the hole for the bladder and finish bladder tube hole and the entire engine mount with slow cure epoxy.  I’ve used five-minute epoxy for this in the past and I find that it will discolor and soften when fuel gets on it.

The Finished Model

All in all, this is a great kit.  The only problems I had were assuming things would be done the same way as many other models using similar construction methods rather than paying attention to how this one is done.  Thanks to Stan Fronabarger for making all his various excellent kits available for us. Flying Lines photo.

At The Field

The Raunchy flew great right off the board.  I flew it on .015” X 60’ lines as the original would have been flown.  With its really loose SuperTigre G21 .35 it was quite fast.  I didn’t time it, but it was way too fast for any speed limit event.  It makes a great addition to my fun fly fleet as it would be a shame to slow it down to fly Vintage Combat with.