The Return of the TigerKitten (2)

This is what it's all about. My wife, Teryl, is holding one of the original TigerKitten prototypes from the early 1990's. This particular airplane is over twenty years old (no, I don't fly it any more)...it's the one that appeared on the kit box label from Ace RC as well as in many magazine ads of the time. The finish in this one is Sig Butyrate dope over Sig Koverall fabric. I'll be using even lighter, more sophisticated covering and finishing products on the airplane I'm building here. BTW: Have a look at the "Books By Bob Benjamn" page on this website. I have devoted an entire chapter in Hey Mister, Will It Fly? to the design concept and evolution of the TigerKitten. Read it, you'll like it.

I am using an ordinary Master Airscrew balsa stripper to cut the 1/4" square strips that will become the horizontal and vertical stabilizer edges from a sheet of medium weight, stiff 1/4" sheet balsa. I cut ALL my strip balsa from sheets of the requisite thickness. This accomplishes two things...all the strips are consistent with one another as they all come from the same piece of wood, and the cost is WAY less. Buying pre-cut balsa strips can cost you five to ten times as much as stripping your own from sheet.

All the shaped parts of this kit are laser cut, and the quality of the laser cutting is first rate. Here you can see the short tabs that are left uncut to hold each part in place on the matrix sheet until you are ready to use it. The laser cutting is so clean that without the tabs each piece would be likely to fall out the first time you picked up the sheet. I use an ordinary No. 11 blade for this job.

The original Ace RC kit followed my original design and used laminated balsa tips for all the flying surfaces. At that time laser cutting was not an option. Premier Balsa Kits has chosen to give you the option of using the original contstruction technique OR to build up the tips using laser cut outline sections. For this build I have chosen to follow the kit instructions in order to be able to evaluate whatever differences might exist. Here I have assembled the right horizontal tail tip, which initially comprises both the stabilizer and the elevator, to be cut apart later. I have pinned the three separate parts, E-1, E-2 and E-3 in place and glued them together using thin (fast) ZAP.

Here's the leading edge of the horizontal tail, cut from some of the 1/4" square balsa that I just stripped out, and trimmed to fit accurately against the pre-determined angle formed by the end of E-1. Building aircraft structural joints like this correctly depends on you to MAKE IT FIT. If necessary, throw away a piece of balsa that's cut too short and make another...not doing that is an open invitation to distorted structure and weak joints.

A miter box is a good way to keep end cuts like this one squared off...but....if the angle doesn't match the slots in the miter box, you'll need to cut as close as possible with your knife blade and then use a sanding block to true-up the joining surface as accurately as you can. This is the leading edge strip that I assembled in the previous image.

There are several ways to mark a piece of balsa for cutting. This is another piece of that 1/4" square strip I just made. It's going to become the stabilizer trailing edge. I could have marked this cut with a pencil, but scoring it lightly with my cutting tool (the good ol' razor blade) to mark it accurately works just as well. NOTE: I am only marking the piece here; I'll remove it from the assembly and cut it on an open, flat spot on my work board so that the force of cutting the strip does not crush or distort anything else.

This is the joint I made using the 1/4" square balsa strip we cut in the previous image. The temptation to force, or squish, or otherwise fake your way through a joint like this will never go away. Take your time, get it right, do it over if necessary, but walk away from the piece of structure you are building knowing that there are no excuses left behind for the way you did it.

Here I am marking the 1/4" square balsa elevator leading edge to be cut off where it will attach to the 1/4" dowel elevator joiner.

This is the other option for cutting strips to length. I'll move the marked elevator leading edge to a clear spot on the board for cutting. In this instance I'll use my miter saw, since the cut -off is at 90 degrees.

This is the beginning of the elevator center section assembly. Notice that I have used a round wood rasp (file) to cut the diagonal 1/4" square elevator inboard end to match the curvature of the joiner dowel.

The next step is sanding the outer edges to an exact match with the outline defined by the plan. This is the left leading edge of the horizontal tail. Same deal for the inboard end of the elevator.