The top deck is really a removeable upper front fuselage. It provides excellent access to your battery pack as well as to whatever components of the radio system you choose to mount on the upper side of the inner tray. It's big enough and important enought that a good fit and a neat appearance really matter. Premier has made the job of building it quite a bit easier by providing a laser cut base/outline to which everything else gets glued. I began assembly by gluing the 1/8" x 3/16" balsa base strips along either side of the ply base plate. These lie flush with the outer edge of the plywood, and must be bent gently to follow the curve at the front end of the base plate. For this part of the assembly I am leaving everything pinned to the building board, nice and flat.

I chose to begin laying out the first fuselage side frame by positioning the laser cut balsa wing saddle and landing gear mount reinforcement. These two parts are positioned in reference to a 3/16" sq. balsa upright which I have fitted in place here. Thin (instant) ZAP is the adhesive of choice here as it allows me to locate and pin each of the parts involved in exactly the position I want, then add adhesive.

Here I have fitted the top longeron to the 3/16" sq. balsa upright that supports F-1, as well as the 1/8" x 3/16" balsa diagonal brace that lies directly behind it. This is an example of the way you should make all the joints in a model structure fit... it doesn't make sense to have the advantage of precision laser cut shaped parts and not have the joints you fit yourself match that level of accuracy.

I have all the longerons, uprights, and diagonal braces in place along with the laser cut components...this defines the structure of the side frame.

The basic fuselage structure consists of two identical side frames connected by various cross members and formers. The best way to to be sure both of the side frames are actually identical is to build one directly over the other. That's what's going on here. I have completed the first side, sanded the structure smooth with the good old sanding block, and covered it with a new sheet of plastic wrap while it is still in place on the plan. (It will be necessary to move and reset the pins that are holding everything in place, and then insert new pins as necessary to hold the new/top parts as they are assembled.) Here I have the laser cut wing saddle in place to begin constructing side two.

Here's another quick look at the way the various 3/16" sq. balsa longerons, uprights, and diagonals are going to fit against the wing saddle as I build side two in place over the first side frame.

The trick to building really accurate fuselage side frames is block sand them aggressively while they are still pinned to the building board. Here I am using 80-grit production paper, which is coarse enough to cut through all the hard spots of glue neatly without compressing the balsa. The important thing here is to sand off enough material to get a flat, true surface. Don't leave ridges or low spots. Here I'm sanding the second side, still in place. When it's done I'll remove it along with the top sheet of plastic wrap and repeat the operation with the first side.

A 1/64" plywood doubler is added to the inside face of each of the side frames before we go any further. These will be laser cut parts in production kits, so I have not gone into detail on making them. I used ZAP A GAP for this operation to give me time to spread an even layer of adhesive over every part of the side frame that is going to contact the doubler.

The side frames are assembled upside down over the plan in order to take advantage of the flat, straight top longeron as a reference to keep the rest of the structure square. This is the left side as seen from what will become the inside of the fuselage. I'm using an actual drafting square to get the alignment right at this stage before I proceed further. The side frame is pinned through the top longeron to the building board in several places.

I have added the laser cut plywood landing gear mounting plate and the rear wing mounting bolt plate ( F-2 and F-6) as well as the 3/16" sq. balsa crossmembers that correspond to their positions between the top longerons.This is probably the most critical part of the fuselage construction where correct alignment is concerned.

Here's another look at the basic fuselage framework all squared up and glued back to the wing trailing edge station. Notice that I have not yet made any attempt to pull the sides together at the tail.

Got it right! I'm double checking that the fuselage side frames are assembled square to each other and the building board (which is my reference for all alignment) before I move to the tail.

The vertical members at rearmost point of the fuselage are 3/16" sq. balsa. When they are drawn together and glued, they will have to match the width of a 1/4" thick rudder. It's necessary to bevel the inside face of each one so the final outside dimension will be 1/4" , not 3/8". I'm using an 80-grit sanding block for this, with the assembly still flat on the building board.

The rearmost uprights of the fuselage side frames form what is also referred to as the tailpost. In the last step I beveled them to match the 1/4" rudder leading edge. Now I'm using clothespin clamps to hold them in exactly the right position while I use fast ZAP to glue the joint.

All the fuselage crossmembers are 3/16" sq. balsa. Cut them in matched pairs to align the side frames with the plan. They all get the same ZAP treatment once they are in place.

Check the assembly AGAIN to be sure it's square. If you make a mistake in alignment here, it gets harder to fix with each successive step you complete.

I'm using a bubble level to be certain the fuselage frame is squared off before I go on to work on the the wing attachment structure.

Prior to positioning the wing on the fuselage assembly I measured and marked a centerline equidistant from each tip. I also marked a center point on the leading and trailing edge station formers. With those matched up, I used the long metal straightedge as an aid in setting the wing at exactly a right angle to the fuselage.

I'm using an older model Robart incidence meter to check that the wing is set at an angle of three degrees positive. Remember that the entire airplane is assembled upside down, so the meter will read out at a negative value.

I used the pre-drilled holes in F-3 to mark the wing leading edge at the center and drill holes for the 1/4" dowel mounting pegs. These extend all the way back to the main spar doubler and must be glued securely. I used ZAP A GAP applied to the inside of the opening before inserting each dowel.

Here's a look at the inside of the nose structure so far. I have added pieces of 3/8" quarter-round balsa as corner gussets along the back of F-1

The formers that create the raised portion of the rear fuselage (the "turtleback") are added now. I am using a square to make sure F-7 is perpendicular to the top longerons.

This is a better look at F-7 through F-11 in place.

The top stringer is a piece of 3/16" sq. balsa, which is intended to lie straight as seen from the side. I'm using a steel ruler to check ...this is where you need to trim the top of one or another of the formers if necessary to keep the stringer from bowing or bending.

The top stringer is glued in place. It ends flush with the rear face of F-11.

The top center rear deck stringer is 3/16" sq. balsa. All those on the sides are 1/8" x 3/16" balsa, and it's best to add them one at a time, alternating from one side to the other to minimize the chance of pulling a twist into the structure. I used fast ZAP here, holding the stringers in contact with each former in turn to get the alignment exactly right.

The best way to locate the position of the side stringer is to measure off the plan and mark a location where the stringer crosses each upright in turn.

The fuselage side stringers rest on the top of each of the uprights, but are recessed to lie flush with the tailpost.

All the rear deck stringers are in place now.

Here the left side stringer has been installed, using the locating marks I made earlier.

The surface created by the longerons, F-1 former, and the side stringer must be sanded to provide a mounting base for the side sheeting that comes next. Notice that the surface is not flat...the stringer creates a bulge that will cause the sheet to assume a shallow convex curve.

The fuselage side sheet is a complex part that was not laser cut in my early kit. I'm not sure how this will be presented in production kits, so I'll show you how to mark and cut it yourself. I cut a piece of 1/16" balsa sheet from a 1/16" x 4" x 36" sheet long enough to extend from F-1 to the rearmost point on the side sheet. Here I am using the top edge (along the top longeron) as a reference, as it provides the only straight line I can use as a starting point. I have used clothespins as clamps to hold the top edge of the sheet to the longeron.

With the clamped-up assembly turned over I can mark the cutting line along the wing saddle and the rest of the bottom edge of the fuselage onto the side sheet blank.

Without cutting the plan it's hard to mark that inside cutout curve onto the sheet blank. I traced the curve off the plan onto a sheet of ordinary copy paper (you can see through it OK if it's held tight against the plan), then cut out the pattern. Here I am tracing the resulting curve pattern onto the side sheet.

This is the side sheet blank with the inside curve marked, ready to cut, resting in place on the fuselage side where I'll ZAP it pretty soon.

This side sheet is going to have to assume a gentle compound curve to fit tightly against all the underlying structure. The easiest way to get a sheet of balsa to do this is to wet it with a light spray of water ...only on what you want to be the outside surface of the bend. The sheet will automatically curl away from the wetness AND become more pliable at the same time.

ZAP A GAP is my adhesive of choice here, as it allows me to spread an even layer of glue over all of the longeron, former and stringer surfaces where the sheet is going to stick.

It's easy to press the wet sheet into place all around the edges where you want it to stick using the palm of your hand. ZAP A GAP will grab and hold a joint like this in ten seconds or so.

There are lots of places in the TigerKitten fuselage assembly sequence where the edge of a part may not seem to fit right away. Don't sweat that...it's all planned to come out right. Here the best way to blend the rear point of the side sheet into the rest of the structure was to design in a longeron cap of 1/16" x 3/16" balsa, which you see being fitted here.

One of the features that gives the 'Kitten such a finished look is these stringer inserts, which are provided laser cut slightly oversize to permit you to trim and bevel each one for a perfect fit between each pair of stringers after YOU have assembled them. You can see where a bevel needs to be sanded into this one.

I have sanded a bevel into each of the edges of the insert that will fit against the two adjacent stringers...you can see how it's going to slip right into place.

I left just enough material on this insert to give a tight press fit...now thin ZAP is the perfect adhesive to keep it there. All the rest of the stringer inserts go in just the same.

All the stringer inserts are in. You can see that the material selected for them leaves some extra thickness to be sanded away, allowing a perfect fit.

Here's what the inserts should look like when you have the entire surface of the assembly sanded.

If you have a thing for scale models of the Good Old Airplanes, this is about as good as it gets.

This is the sheeting for the upper front of the left panel. It extends from the junction of the W-1 ribs all the way to the tip, but does not overhang W-5. The rear edge lines up with the rear face of the spar web inserts and the front edge is cut for assembly to extend just slightly beyond the 3/16" sq. balsa leading edge to provide enough material to "sand on" when it's time to create the leading edge radius. I have given the outer surface (the side you see) a light spray of warm water to induce a gentle bend along the grain. I want to begin assembly by using glue ONLY at the leading edge for the best possible control of the sheet, but I want to key it in relation to the top spar, so I have used several pins to hold it in place. So far I have not used any glue. Watch what happens next.

Because I sprayed the top/outside surface of the balsa sheet with water a few minutes ago I can easily bend it like this, up and away from the leading edge, to get the SLO ZAP exactly where I want it. (I am holding the sheet in the bent position with my other hand, out of the picture.) I'll apply a generous bead of SLO ZAP all along the 3/16" sq. balsa leading edge and up about 1/2 inch onto the front of each rib, then close up the joint.

With the rear edge of the sheet held at the spar with pins to keep it from moving, I have applied SLO ZAP all along the leading edge, where the sheet has been cut to overlap by a small margin. Now I am using a steel straightedge to roll and press the front edge of the sheet tightly against the leading edge until the ZAP grabs.I held the rear edge of the top sheet in place on the spar while I glued up the front edge. Now I can unpin the rear edge and roll it up to get access beneath it without disturbing the alignment. Here I am applying ZAP A GAP to the top edge of each rib as well as the upper surface of the the top spar. The sheet balsa is still wet and easy to bend at this point.

The top sheet is attached at the leading edge and ready for this part of the structure to be closed up. I am adding a generous bead of ZAP A GAP to the top edge of each rib where it will contact the inside surface of the balsa sheet and all along the top surface of the spar. The next step is to roll and press the top sheet into place. The sheet is still wet.

I have already added the 1/16" balsa sheet to the center section from the rear of the top spar back to the trailing edge. (Sorry, I was having so much fun I forgot to get a shot of that for you.) The capstrips come next. Th Kitten is a bit different from some airplanes in that I use a long spanwise capstrip along the top of the balsa trailing edge...this provides a 1/16" raised lip against which all the rib caps fit smoothly. Here I have a piece of 1/16" x 3/16" balsa that will be cut to fit the space between the leading edge sheet and the trailing edge cap.

With the individual rib cap cut to length I have added ZAP A GAP to the top edge of the rib and pressed the cap into place. The "medium speed" adhesive allows me to position the strip accurately and still cures quickly enough that holding it in place while it "sticks" is practical. No need for pins.

This is the top surface of the left wing with the leading edge sheet, the trailing edge cap, and all the rib capstrips in place. Notice the 3/16" sq. balsa spacer strip under the rear of the ribs, angled forward at the tip to provide washout as I explained earlier. Those are lead block building weights I use to keep the wing structure flat on the board without having to stick more pins through it.

I rocked the assembled wing over to rest the right panel on the building board and held it down with those building weights in preparation for adding the trailing edge and rib caps on that side. That part is really critical...RIGHT HERE is where adding those next few pieces of structure, the capstrips, is going to help lock the structure into its final shape...that is, flat, twisted badly, or washed out just the right amount.

The Kitten uses full span strip ailerons, in part because they work so well as flaperons (which we are going to use.) Taking my measurements from the plan, I cut four pieces of 1/4" balsa sheet to fit the profile of the center section trailing edge. These will be laminated to make two half-inch thick pieces, one for each wing panel. These will be trimmed to accept the DuBro No. 186 strip aileron horn assemblies.

This is the laminated trailing edge block for the left wing. I have taped it in place to mark where it needs to be tapered to match the airfoil section dictated by the rest of the wing structure.

I am using a small block plane to cut the left trailing edge block to the correct profile. This is a job I'll finish with a sanding block.

Both trailing edge blocks have been planed and sanded to final shape. I beveled the faces where they join at the center and have spot-glued them into place to check alignment and do any necessary final sanding to be sure they blend smoothly into the rest of the wing.

This is another job for the good old sanding block. When I'm done I want those trailing edge blocks to look like they are a seamless extension of the rest of the center section.

I have cut the trailing edge blocks loose from the wing after making sure they are sanded to fit as accurately as I can get them. This one is clamped in a vise between a couple of scraps of wood so I can use a curved chisel (a gouge) to rough out the slot into which the long shaft of the strip aileron horn will fit.

As assembled, the top and bottom 1/16" balsa leading edge sheets extend just a bit past the front of the 3/16" sq. balsa leading edge and stop. This is what they look like before any trimming or sanding.I like to use a block plane for the initial smoothing and shaping of structure like this. I'll cut off enough wood to produce a smooth, straight working surface while leaving a bit of material for the sanding block to take off.

The next step is to use the sanding block to get the entire length of the leading edge squared off and smooth. When that's done and I have a reliable reference for where the front of the leading edge radius is supposed to be, I'll finish rounding off the contour.

With the leading edge radius sanded in, I am continuing back around the top surface of the wing to blend in/smooth off all the structural joints that are not supposed to show through the covering when I'm done. This part of the job of building an airplane is one that MUST be done slowly and with care. Get it right and keep checking and going back until you are sure it's as smooth as you can get it.

Here's another look at using the sanding block to get the curvature of the leading edge JUST RIGHT before I go on to other things.

The stuctural trailing edge is actually the front surface of the aileron well. Here I am giving it a final sanding pass the ensure that it is squared off and free of bumps.

The first pass over the leading edge used 80-grit production paper to enable me to shape the structure cleanly without having to press down hard and risk distorting anything. I did an intermediate sanding with 120-grit and now I have switched to 320-grit for final smoothing of the surface. The trick is to work with each successively finer grit until all traces of the scratches left by the coarser paper are gone.

I am using a piece of 320 grit production paper to do a final smoothing and rounding of all those curved and rounded edges.

More of the same. I am using 320 grit production paper on a block to finish off the edges of all the capstrips smooth and even with each other. SANDING is not something you do for a few minutes and forget about...not sanding enough is perhaps the most common error new builders make that results in mediocre model airplanes.

This is the beginning of a corner insert...perhaps you could call it a gusset. I have cut "blanks" of 1/16" balsa sheet from the same stock I used for the surface sheeting in order to get similar stiffness, and cut triangular inserts with the grain at a 45 degree angle across the opening and glued them in place.

The sanding block comes out again to dress the surface of the insert even with the rest of the structure.

I used a template to mark the cutting line...in this case I found an odd bottle that had the right radius...and now I am using an ordinary No. 11 blade to make the cut.

Sanding an inside radius like this is hard to do without some help. I'm using an old can with 80-grit production paper taped around it to finish off the cut in a perfect arc.

Here I have a piece of 320 grit production paper on the same can to smooth of the radius to match the rest of the surface. "Noodely little stuff" like this DOES make a difference in building the kind of airplanes that other aeromodelers will go out of their way to look at.

I built the ailerons after the rest of the wing structure was complete so they would match up correctly. Here I have fixed the left wing panel to the building board over the plan and covered it with plastic wrap. The piece I am holding is more 1/16" sheet balsa and will become the bottom surface of the left aileron.

Sorry...I blew the focus on these shots. This is the best one I could get for you. This is the end-on view of the lower aileron surface showing how I beveled the rear edge so the the upper surface sheet will fit neatly against it.

With the bottom surface sheet in place, I am adding the laser cut aileron ribs using ZAP.

All the aileron ribs are in place on the lower surface sheet. I have made an insert from scrap 1/4" x 1/2" balsa, tapered it to fit, and glued it in place at the root of the aileron where the short end of the DuBro aileron horn will fit into it.

I have cut a top surface sheet using the plan as a pattern.

I assembled the top and bottom surfaces of the aileron, joined at the trailing edge, with more plastic wrap around the outside of the assembly and clamped everything in place using clothespins.

I added ZAP from the front, which is still open, to bond each of the aileron ribs and the surface sheets all along the rear edge. That plastic wrap keeps the clothespins from becoming part of the aileron.

The leading edge of the aileron is just another piece of 1/16" balsa sheet cut to fit. I used my sanding block to smooth and bevel the front of the assembly I glued up in the last step so the sheet would fit smoothly against it and then proceeded with this step.

This is the finished aileron with all the edges sanded smooth.

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.

This is the TigerCat as I have been flying it for several years. The design is an enlargement of the TigerKitten, using the same airfoil and aerodynamic layout, but with different flying surface shapes and a different cowl. The airplane you see in flight here at our field in Olympia, WA has been flying for about ten years using an origianl brushed, geared Astro Cobalt 25 motor, runing first on NiCds, then NiMH cells, and recently on a LiPo pack. What's going to happen npw is that I'll remove the old Astro motor along with the old ESC and the entire ten-plus years old Airtronics radio system and replace it with equivalent state-of-the-art equipment.

With the cowl removed you can see the old Astro 25 motor and gearbox where they have been hard at work since the late 1990's. This motor is still capable of flying the airplane, but it's time to move up to something WAY BETTER.

Here's another look at the old installation from the back. You can see how the old motor was inserted from behind the firewall/motor mounting bulkhead and prevented from rotating under operational torque by stop blocks I added to the rear face of the firewall.

This is the motor battery pack tray/mounting area as it existed in the Astro powered airplane. This is one part of the TigerCat that will not change much.

This is the same portion of the fuselage seen from the bottom, showing the old Airtronics 72 mHz installation. That's a fifteen-plus year old Astro 207 brushed ESC at the left. The servo cables at the bottom are the aileron extension connectors.

The old astro geared motor is still inplace on the firewall/mounting bulkhead. Next to it I am holding the Cobra 4120-18 brushless outrunner (http://www.innov8tivedesigns.com/product_info.php?cPath=21_120_124&products_id=860 from Innov8tive Designs that's going to replace it. As you can see, the biggest problem I'll have to solve is how to compensate for the difference in the overall length of the two motors.

The solution to the problem of the new motor being shorter than the old one was to build an adapter mount that would make up the difference. As it turned out, a couple of measurements showed me that I needed something to fill in exactly one inch of open space that would remain between the rear of the new Cobra motor and the existing mounting bulkhead when the prop driver was in position in relation to the cowl, so that the propeller would end up in exactly the same relationship to the airplane as it had been with the old motor in place. The Cobra motor comes supplied with a rear mounting fitting that attaches with four machine screws to a flat surface, which my old mounting bulkhead provided. I designed a base plate of 1/8" plywood to mount to that, a 1/4" plywood motor mounting plate, and spaced them apart with a pair of 5/8" x 1/"4" spruce blocks. Here the motor plate is drilled out to accept the rear shaft extension and the mounting screws, ready for attachment to the base plate.

I used ZAP-A-GAP to join the motor mount assembly to the base plate.

This is the completed mount adapter i place on the existing firewall. The empty holes in the motor plate will accept 4-40 bolts and already have 4-40 blind nuts installed behind them. The other four socket head screws you see are longer 4-40's tha entend all the way through the assembly to more blind nuts inside the firewall former.

Here I have the Cobra 4120-18 outrunner mounted in place on the new adapter/spacer. One advantage of a mount like this is that it is easily adjustable for short increments of length and/or for thrust line offsets.

Here's another view of the Cobra motor in placce on the new mount, with the three power leads attached to the ESC wires with bullet connectors. Before closing up the cowl to fly the airplane, I'll safety each of those connector attachments with tape so they can NOT come loose unless I want them to.

Remember the part about easy adjustment? All my measurements were pretty close, but not close enough. The front of the molded fiberglass cowl on this airplane is designed to line up exactly with the spinner backplate;when that is accomplished the motor centerline/thrustline is correct. It turned out that I need to tweak the motor a degree or so to the right, and the best way to do that was to add a washer between the upper and lower LEFT motor mounting bolts and the motor base plate. I have loosened all the bolts to get access behind the mount and here I am inserting a washer. There's another one like it already in place under the bottom left mount ear.

In this airplane the plywood panel that forms the entire mounting surface in the middle of the fuselage is a removeable tray. This is the top side, accessible by removing the top hatch that includes the cockpit opening. The double wire with the Deans Ultra connector is the power lead from the ESC. The motor LiPo pack will attach to the dark Velcro.

I replaced the old LiPo with a new ThunderPower 45C 4400 mAh 5S pack.

Here is the new Airtronics 92824 8 channel 2.4 gHz receiver in place in front of the new rudder and elevator servos...this is a view from the underside of the airplane. The dual antenna leads are held in place with a couple strips of masking tape...off the right (the rear of the airplane) they are arranged in a 90 degree orientation to each other per the Airtronics manual.

These are the new rudder and elevator servos as seen from the top of the equipment tray.These are Airtronics 94842 Digital BB output servos which will give me a bit of overkill in terms of control power and the precise centering I want to make this "Golden Age Classic" airplane fly smoothly and gracefully.

I used a pair of Airtronics 94746 Low Profile, heavy duty digital servos for the ailerons. I wanted the extra power and durability because this airplane is set up using full span ailerons that double as flaperons, and the control forces can be substantial at higher airspeeds. I'm using dual servos to take advantage of the capabilities of my new Airtronics SD-10G transmitter to control each aileron independently in order to get precise differential throw AND to make use of individual adjustment and servo speed (delay) control when I activate the flaperon function.

I used the new Innov8tive Designs Cobra 80A ESC, which is provided with a plug-in module that permits you to set all the necessary parameters directly, without having to guess at getting transmitter stick inputs right. (http://www.innov8tivedesigns.com/product_info.php?products_id=903) This ESC includes a high capacity switching BEC (battery eliminator circuit) that will reliably power servo installations like the one in this airplane without overloading.

This is a closer look at the 92824 receiver with the Cobra ESC in place ahead of it.

This is the Cobra 4120-18 motor ready to be covered up by the cowl. You can se that I have safetied the power lead bullet connectors and tucked the wires out of the way.

The TigerCat design features a long, deep cowl that covers everything neatly. It's held in place by those little screws you see along the rear (left) edge.

I used a DuBro 2 1/2" plastic spinner. Here the backplate has been bushed to fit the output shaft of the Cobra motor for a tight fit.

I chose the Cobra 4120-18 for its ability to swing a large propeller. Here I am using a VarioProp 12C two blade hub with 15" diameter scale profile blades. I added an extension propshaft (available directly from Innov8tive Designs) to permit mounting the deeper-than-usual VarioProp hub assembly.

I painted the white DuBro spinner using an airbrush and the same Stits PolyTone Insignia Blue that you see on the cowl. The VarioProp blades are normally black...I did a careful balance job on mine, sprayed them with silver PolyTone, and added a couple of Hamilton-Standard decals just for the cool factor.

This is what it's all about. The airplane is just off the ground here, at about half throttle. I'm holding a bit of right rudder...standard practice for any high-powered taildragger...and letting the TigerCat fly itself off the grass.

This is just an easy banked turn past the strip.

Smooth, straight-and-level flight looks really good with an airplane like this, but it's not as easy as you might think. The built-in stability of this design goes a long way toward taking the work out of those long, straight fly-past maneuvers.

This airplane is capable of any and all Classic Era aerobatics you can think of, and then some, but it is NOT a 3D model. Close-in, coordinated turns like this give you the feeling that you're flying a time machine in miniature.

Let's go the other way. That old-time pilot looks pretty happy with the job he's found. As soon as my friends at Premier Balsa Kits are ready to announce production of their new kit for this airplane, I'll let you know right here at rcmodel.com.

I'm using DuBro 3" Super Lite wheels, but I'm going to modify them in order to be able to add some custom made hubcaps that will require recessing the wheel collars into the wheel hubs for clearance. The first thing I had to do was drill out both hubs to fit the 3/16" brass tubing I added to the wire axles, and then countersink each hub using a 7/16" Forstner bit to cut into one side by half the depth of a DuBro 3/16" wheel collar. (I discovered by doing some trial measurement that this would permit the hubcaps I'm planning to make to fit without binding. NOTE: You don't have to do any of this...it's OK to use the stock wheels and let the wheel collars show, if you prefer.

Please excuse the crummy focus on this shot...it's the best of the ones I was smart enough to save. This is the main axle bushed out with a piece of 3/16" brass tube to fit the wheel. I have used a cutoff wheel in my Dremel tool to grind a squared-off notch where the setscrew of the DuBro wheel collar will touch to provide a mechanical joint that will not let the collar slip under side loads.

This is the same assembly with the wheel slipped into place. Same game on the bad focus.

Here I have the DuBro wheel collar in place. You can see how it is recessed partway into the wheel hub, in the area I cut out. I determined the depth of this cutout by measuring how much clearance would be necessary between the outside edge of the collar and the custom hubcap I'll describe next.

Aluminum cans make a good source of material for all kinds of model airplane parts, no matter what was originally inside them.

I covered the bottom of the can with some masking tape to provide a surface that would be easy to mark with a pencil, then traced a circle the same size as the outer edge of the wheel hub.

I used a pair of short, curved-blade snips to cut the rough shape of the hubcap out of the can bottom.

A little filing and sanding turns the rough blank into a finished, custom aluminum hubcap. The convex shape of the can bottom provides just the right clearance between the hubcap and the wheel collar.

I used a bead of ZAP Gel around the outside edge of the hubcap to attach it to the wheel. For a small model like this one such a bond is tough enough to stand up to normal loads. If it becomes necessary to get the wheel off, it's no big deal to slip a thin blade between the cap and the wheel and slit it loose without deforming it.

Those stick thingies between the flying wires are called "javelins". On full scale airplanes they help prevent resonant vibration from creating potentially destructive standing waves in the wires at higher airspeeds. That can happen with models as well, and it's a good thing to avoid. Beyond that, adding flying wire javelins to a wire-rigged biplane just adds cool factor. These are just lengths of 3/16" dowel with the ends rounded and sanded smooth.

With the javelin held in place I marked the exact point at which each wire will cross it.

I cut a slot halfway through the dowel where each wire will intersect it in turn. As the various flying and landing wires intersect the javelin at varying angles it's necessary to reproduce those angles accurately when cutting. In the case of my Great Lakes, a 1/8" bandsaw blade turned out to be exactly the right width to match the thickness of my wires.

If you measure and cut the slots for the wires properly, everything will fit in place like this. The javelin should be cut and located so that each of the wires runs dead straight for its entire length.

I used a drop of ZAP-a-GAP to lock each wire into its respective slot in the javelin.

In full scale practice there are several ways of securing the wires to the javelins. In many cases the assembly is wrapped with tape to finish it off. Here I am using 1/8" fine-line masking tape to do that job in miniature.

With each javelin-wire junction wrapped, I sealed the assembly with a heavy coat of clear nitrate dope, the same stuff I used to seal the covering. This is a good place to use traditional shrinking, rather than non-tautening, dope.

OK, guys, are you ready for this? The old FlyLine Great Lakes Trainer, built from a leftover, swap-meet-refugee old-time stick-and-tissue kit, is DONE.

This is the new grass at our flying field in Olympia,Washington...just exactly the kind of surface this airplane was intended to operate from.

That's a 13x6 Xoar prop, which tuns out to be just about right for this airplane. You can see the dummy exhaust stacks that I carved from balsa clearly from this angle, along with the working shock absorbing landing gear main struts.

Here's a good look at the engine cowl from the other side, showing those louvers I spent all that time on.

The Great Lakes 2T-1A is a classic Golden Age aerobatic biplane, and all that character is easy to see here.

LET'S GO FLYING!

Here the yellow inner tube is cut off to length and I have threaded the 2-56 metal rod into place.

The stock 2-56 Sullivan clevis is threaded onto the rod and attached to the rudder servo output arm with the short piece of rubber tube that is provided slipped over the clevis as a safety guard to prevent it slipping loose. There is sufficient room at either end of the clevis assembly to permit full freedom of movement of the servo

Both the rudder and elevator servos have been connected to their respective control surfaces and I have placed the Airtronics RX-6000 2.4 gHz receiver in position held down by a couple of pieces of sticky back hook-and-loop fastener. On this airplane I am using two servos, each on its own channel, to actuate the ailerons. A separate extension cable for each of them is already plugged into the receiver. These will connect to the aileron servo leads attached to the wing. The receiver antenna cables are not yet fixed in position.

The Airtronics 2.4gHz receiver uses a dual antenna arrangement, and the ends of both antennas must be arranged in a ninety-degree orientation to one another. As there will be no appreciable stress or load on these antenna wires in operation, a short piece of masking tape is sufficient to hold each of them where I want it to be. The servo cables coming out of the receiver are bundled neatly using a small nylon cable tie. I do this to be absolutely certain that nothing is loose and free to flop around inside the airplane in flight.

I'm going to include semi-functional wing wires on this airplane...they will bear a symbolic load and look like their full scale counterparts, but will not be necessary to hold the airplane together. In that case I would have built load bearing anchor points into the primary structure. This is a sample flying wire attachment pin made from ordinary hobby shop steel wire, bent into a loop and crimped to permit secure attachment.

The dummy engine is going to be mounted by the valve covers as part of the cowl. As this is not an exact scale representation, the fit between the cowl and the engine is not perfect. In an ideal case we would build small brackets to attach each valve cover to a mounting ring inside the cowl;however, in this case each of the dummy valve covers needs to be cut back about 3/32" with coarse sandpaper to fit where it belongs. As this part of the engine is going to be permanently hidden, that doesn't hurt anything.

On the full scale radial engine the cam rings are located inside the portion of the crankcase just ahead of the cylinder attachment flats. Using reference photos for the engine I am representing I made locating marks for each pushrod housing base (eighteen, since this is a nine cylinder engine and each cylinder has two valves and thus two pushrods.) I used short pieces of 3/36" aluminum tubing from the K&S rack at the hobby shop, cut the equired number to length, and drilled holes in the crankcase to accept them.

Each pushrod tube base is glued into its own hole using ZAP-A-GAP. As each one is positioned in turn I aligned it with a piece of pushrod tube slipped into place. Note that on this engine (a P&W R 985) each pushrod tube emerges from its base at an angle, slanted back toward its respective cylinder.

Here you can see the crankcase front all sanded to final shape with the pushrod tube base holes drilled and the base tubes assembled.

The parts of the engine that are assembled so far are the ones that are going to be painted...everything else will be bare metal or rubber. I have sprayed the entire engine casting silver using my favorite Stits Polytone and masked off each of the cylinders prior to painting the crankcase.

I sprayed the crankcase with Stits PolyTone Madrid Red (a close match to the color of the case on the engine in my reference photos for the full scale airplane. (http://www.stits.com/store/poly_lite_qts.html). The ignition harness ring around the perimeter of the crankcase is more 3/16" K&S tubing bent by hand around a bottle that happened to be the correct size.

There are too many individual differences among the various engines you might encounter for me to describe every possible detail. On my P&W R-985 the ignition harness ring is mounted to the crankcase by small metal brackets and bolts. Using my photo references I cut a strip of .007" lithoplate (aluminum), snipped it into short lengths, and bent each of the pieces in turn into a bracket. Each simulated ignition ring mounting bracket gets assembled to the ring housing using SLO-ZAP.