Wing Overview The standard Terminator wing has a flat center section with polyhedral tips. The Terminator center section is a flat one-piece core, 21" long, with a 7" chord and a standard 8.01% thickness S4083 airfoil. The Terminator tip section is 20" long, and tapers from a 7" chord to a 5" chord. The S4083 airfoil is transitioned from 8.01% thickness to 5% thickness from the tip section joint to the wingtip, and there is 1% of washout at the tip. The polyhedral tips are attached with 4" of dihedral under each wingtip. For those who have not done composite wings before, the general construction sequence is: Cut foam wing cores Cover with balsa sheeting or fiberglass (still in separate panels) Join the panels at the indicated dihedral angles If balsa sheeted, finish the wing to prevent the wood from picking up moisture Note: The trailing edge of the Terminator standard wing is straight, across both the center and tip sections - all of the chord taper is done with a leading edge sweep. Please see the pictures on the intro page for pictures of the wing layout. What Kind of Foam Should I Use? This is one of the most common questions we have been asked. We have had good luck with the pink foam sold in sheet form at Home Depot. It seems to be much stronger than white foam, at a very slight weight penalty. For us, the strength advantage is worth the tradeoff, since it is harder to fold the completed wing. For a stronger wing, use pink foam for both the inner and outer panels. For a lighter wing, but not as strong, use Home Depot pink foam for the inner panels and 1 lb virgin white foam for the outer (tip) panels. Wing Core Templates Below are templates in two formats for both fiberglass bagged and balsa sheeting wing designs. Templates are provided in Acrobat PDF and CompuFoil 98 LFT format (these templates use an airfoil included in the CompuFoil Airfoil Library - without the library they will not load). CompuFoil 98 will give you the most control over template creation, and allow customization easily. On the other hand, creating templates from a PDF file does not require you to purchase software (but you must check the template printouts as noted below to be sure they're sized correctly!). ADOBE ACROBAT FORMAT TEMPLATES (.PDF) Section Fiberglass Bagged 1/32" Balsa Sheeted Middle panel and innermost template of tip section (the one that connects to the center panel) termctrg.pdf termctrb.pdf Wing tip template (with 1% washout) termtipg.pdf termtipb.pdf NOTE: Be sure to check the dimensions of your template printouts if you are printing them using the Adobe Acrobat PDF files! On most printers they will be full size, but on some printers the size may not be correct! The chord of termctrg.pdf and termctrb.pdf should be a full 7", while the chord of termtipg.pdf and termtipb.pdf should be a full 5". If your printer does not render these at full size you have two options. You can either take the printouts to a copy shop and fiddle with the enlarge/reduce function of their copier until they come out the right size, or purchase a copy of CompuFoil, and use the CompuFoil LFT templates below instead. (The CompuFoil web site is at http://ourworld.compuserve.com/homepages/compufoil/). LEADING EDGE TEMPLATES Here are leading edge templates, to help shape the leading edge correctly. Each template has two airfoil curves; the inside curve is for the foam on a sheeted wing, the outside curve is for the foam on a bagged wing (or either completed wing). Section Template Middle panel and innermost template of tip section (the one that connects to the center panel) trmctrle.pdf Wing tip template trmtiple.pdf COMPUFOIL 98 LOFT FORMAT TEMPLATES (.LFT) NOTE: These templates use an airfoil that is included with the CompuFoil Airfoil Template library option, but is not included in the "base" CompuFoil 98 product. Without the Airfoil Library option, CompuFoil will likely not be able to load these templates. Section Fiberglass Bagged 1/32" Balsa Sheeted Middle panel and innermost template of tip section (the one that connects to the center panel) termctrg.lft termctrb.lft Wing tip template Note: Make sure to add 1% washout to this template in CompuFoil before creating your templates. (The LFT file format does not preserve the washout settings. To set the washout angle in CompuFoil 98, select the airfoil menu and then click on the washout angle menu item.) termtipg.lft termtipb.lft NOTE: Be sure to check your CompuFoil printouts for accuracy. Not all printers are accurate at the level needed to create clean airfoils - don't assume that yours is without checking it. To check your printer calibration with CompuFoil 98, use the Adjust Printer Aspect Ratio item on the Defaults menu. (Make sure to write down the original settings before tinkering, just in case!) Click here to download a PKZip archive containing all four CompuFoil LFT files (this is helpful if for some reason CompuFoil will not open the airfoils correctly when you click the links above. Finishing the Wing The Terminator wing can be finished either with balsa sheeting or glass bagging techniques. BALSA SHEETED OPTION (balsa sheeting step-by-step created by Dan Griscom - thanks!) If you are going to balsa sheet the wing, find enough sheets of 30" x 4" x 1/32" balsa to cover the surface. (If you will be building a bunch of Terminators in a club-style project, you should consider buying a 100 sheet lot of balsa so that you can pick the weights that you want and end up with matched panels.) The balsa sheeting can either be attached with 3M77 spray adhesive, or if you (or a club buddy) has vacuum bagging facilities you could bag the balsa on with epoxy. NOTE: 3M77 is a contact cement - you get one try to get the sheeting aligned - be careful to get things lined up before you let the sheeting touch the core! Tape a pair of 1/32" x 4" sheets together with Scotch tape. Bend the joint open, apply some Elmer's or carpenter's glue to the edge joint, open the sheets up flat, and wipe excess glue off of joint with a damp paper towel. Glue six pairs of sheets this way and let them dry overnight. Put the bottom core blank on a flat surface, cover with wax paper, and place a wing core on top. Cut the 8" balsa sheet to fit the core, leaving extra on all edges. Spray the balsa sheet and the core with 3M77, and let dry until tacky. Starting at the trailing edge, touch the balsa to the core and smooth the balsa onto the core until you reach the leading edge. Trim the balsa flush to the core, except for the trailing edge. Since the foam core doesn't reach all the way to the trailing edge of the airfoil, the balsa should overhang 1/3" past the trailing edge on the center section and at the inner ends of the outer sections, and 3/4" past the outer ends of the outer sections. Put the top core blank upside-down on the flat surface, and put the half-covered wing core upside down on top. Spray balsa and core with 3M77, let dry until tacky, apply balsa, trim to core (again, except for the trailing edge). Stack bottom core blank, wing, and top core blank, weight down until flat, and let dry for 24 hours. Sand the leading and trailing edges to shape, and run a length of 3/4" tape along the leading edge to cover any leftover gap. Finishing the sheeting is easy. Just sand with 320 (lightly - don't go through it!), and then finish it with either water-based polyurethane or an alcohol-based shellac (make sure you get the kind with built-in sealer) like Bullseye. Applying either one with a 2" brush is quick and creates a nice finish. Finish sand and you're done with the wing. Option: Tinting Polyurethane for a colored finish VACUUM BAGGED FIBERGLASS OPTION For general hard use, bag the center and tips with 1.5 oz cloth. The steps below should yield a 4.5 ounce wing: Add a top center doubler of 1.5 oz cloth (5" by full span) Add a bottom center doubler of 1.5 oz cloth (3" by full span) Add two pieces chordwise in the center (measured) of 1.5 oz cloth - one 2" wide and the other 3" wide. These reinforce the center of the wing where the wing bolts will go through. Add a doubler of 1.5 oz cloth to the top only of each tip panel, 3" wide by the full span including the tip. That's it! Try to bag with two ounces or less of resin for the whole wing. If you use a 4" roller it will help you to be light on the application. For a 4.1 ounce light wing, change the tip cloth and doublers to .75 ounce cloth and reduce the amount of resin on them. (Note that if you do "gorilla launches" this lighter wing will fold more easily...). Click here if you want to check out the "How to Bag a 4 Ounce Wing" option page. Now this option is really not for first-time "baggers", but for those of you who want to try something more adventurous, take a look at Bill's Terminator Bagged Tips. This page describes some special work that Bill likes to do on the tips - seems to get a bit more launch height and more tip stall resistance. Assembling the Wing Once you cut the cores for each wing section, they can be attached with a layer of 5 minute epoxy. The center section should be set flat on your work surface, and the tip joint carefully sanded until it is a flush fit with the underside of each tip 4" above the work surface. Once you have sanded the correct angle into the tips, here is a quick and easy way to join them. Find (or cut) something in your shop that is 4" high to use as a tip dihedral brace Using a #11 blade (X-Acto type works well), tap randomly on each mating surface where the panels will be joined. This will make some tiny "woodpecker" holes in the foam surfaces that will be joined, and ensures that the epoxy can flow into the foam and not just form a surface bond. Take some tape (Scotch tape or packing tape works fine) and hinge the tip section onto the center section on the bottom surface, so that when you flex the tip up to the 4" set point the foam is tightly mated. Unfold the tip, leaving the tape in place, mix up some 5 minute epoxy, and brush onto the foam, making sure that the epoxy flows into any foam crevices and the perforations made in step 2. Gently fold up the tip and rest it on the dihedral brace. Excess epoxy will flow out of the top of the dihedral joint - I use craft sticks to "scoop up" the extra epoxy right away - and if you work reasonably quickly you can then wipe off any remaining layer of epoxy with paper towels. When the epoxy is cured, peel off the tape on the underside of the joint, and voila - you're done! If you want to cover up the joint, almost anything will do - electrical tape, covering material, trim sheets, whatever. The wing will not need any extra strength in this joint after the epoxy, so resist the urge to glass over the joint - it's wasted weight! Installing the Wing Hold-Downs We use two aluminum 6x32 bolts (front and rear - about 5" apart) to hold the wing on. The exact location isn't too critical, but on many wings we set up the front bolt 3/4" from the leading edge, and the rear bolt about 5" behind. To keep the wing from being crushed at the bolt locations, make up a couple of "washers" out of 1/16" plywood, about 1/2" in diameter, and glue them to the upper wing surface with thick CA. (These don't need to be round - we cut them 1/2" square and just sand or cut them to be "roughly round"). Fuselage Overview The Terminator uses a simple pod and boom design. The fuselage uses a minimum of parts, yet is quite strong. Dimensioned fuselage plan - click the small thumbnail image above for a large image. *** Don't sweat the specific shape of the fuselage pod, as long as the basic dimensions in the drawings are adhered to. Here's a picture with some experimental fuse pods we've built. Just make sure that the length from the wing to the tail stays the same, the angle of the wing to the tailboom stays the same and there's enough space for your gear and it'll fly fine! But where do I get the arrowshaft for the tailboom? There are archery shops in most cities, and these shops carry a variety of arrowshafts. Several types can be used for the Terminator. We have used arrowshafts from two major vendors, Beman and Easton. We use the Beman ICS 500 whenever we can find them - they are lighter and slightly larger in diameter than the Easton arrowshafts (less flex and lower weight). Note: The standard Terminator tail boom, from the front of the wing saddle to the rear tip of the tailboom, is 26.5"-27". (This is written up this way so that if you choose a different fuselage shape or design it is easy to get the overall tail length correct.) If you cannot get the Beman, then the Easton ACC 328 or 339 will work (in order of size and weight - the 339 is the heaviest - anything lighter than the 328 is likely way to flexible). Almost any carbon arrowshaft will do, although the smaller diameter shafts may take some extra work, and may have too much launch flex. Some are very small diameter - these can be used, but the control wires may need to be run down the outside (CA the sheath in place every couple inches if you opt for this approach). Create the Fuselage Sides Fuselage sides with doublers (click for full-size image) Cut two fuselage sides from soft 3/32 balsa. Hold the two together and sand so they are exactly the same. Using the fuselage sides as a pattern, cut out two 1/64 plywood doublers. (these are best cut with household scissors) Making sure to make a right and left side attach the doublers to the fuselage sides with thick CA. Attach 3/16 or ¼ triangle stock flush with the bottom of both fuselage sides along the full length of the bottom using thin CA Attach 3/16 or 1/4 triangle stock flush with the top of the front 4" of both fuselage sides, using thin CA. Attach 1/8" square balsa along edge of wing saddle, using thin CA, stopping where the boom former will be installed. Assemble Fuselage Fuselage in alignment jig (click for full-size image) Cut the center former from 1/8 light ply. Click here to download an Adobe PDF file showing how to make a very simple jig for aligning the fuselage (5 kB PDF). The braces for the nose former should be 7/8" apart; the braces for the center former should be 1 7/16" apart, and the holder for the rear of the fuselage should be 5/8" wide. Place the sides in the jig upside down and slide the center former into place making sure it is aligned properly with the end of the plywood doublers. Make sure that everything is pushed down squarely on the jig surface and zap the center former with thin CA to hold things in place. Make the nose former from 3/32 balsa and thin CA it in place Add Fuselage Sheeting Adding top and bottom sheeting (click for full-size images) Now you can start sheeting from back to front on the bottom of the fuselage using light 3/32 sheeting cross grained I use thick CA for this and make sure to glue full width on the triangle stock also as you will sand much of the corner away when you finish the fuselage. When the bottom is sheeted the fuselage may be removed from the jig and triangle stock fitted to the top from the center former to the nose former with thin CA. The first 4 inches of the top is then sheeted with 3/32. Mount the Tail Boom Fuselage ready for tail boom attachment (click for full-size image) 1. At this time you must cut the boom former from 1/8 light ply and glue it into position. Make sure to make the hole for the boom slightly oversize so that you have room to align the boom. MAKE SURE THAT THE HOLE FOR THE BOOM IS BELOW THE LEVEL OF THE FUSELAGE SIDE TOPS! Tailboom in fuselage pod, ready for glue (click for full-size image) 2. Slide the tail boom into the former from the rear about 3/16 past the former. Holding the fuselage upright the tail boom will pretty much self center in the triangle stock. Sight from front to back to check alignment. The boom may be adjusted slightly if necessary since we made the hole slightly oversize. When you are satisfied with right to left alignment put a drop of thick CA on top of the boom at the former. 3. Now fill the space between the sides and the tail boom at the extreme rear of the fuselage with tiny pieces of scrap balsa so that it remains aligned right to left but can still move up and down. Final fuselage pod and boom alignment (click for full-size image) 4. Turn the fuselage over and block the rear up so that the wing incidence angle is level with the workbench top. Now block the tail boom so that the top side (now the bottom side since we are upside down) is also level with the workbench top. When you are satisfied that both the wing incidence and the boom are level with the workbench top put a drop of thick CA on the boom at the rear of the fuselage to hold it. Here's an alternate boom alignment method from Dan Griscom. Lay your fuselage side on poster board and draw just the top section containing the wing saddle and rear top of the fuselage to the end. Then, trace the center wing panel airfoil onto the wing saddle, just as the wing will be placed when the Terminator is assembled. Draw a straight line through the chord line of the airfoil (through the center of the leading edge and the center of the trailing edge), extending it about 12" beyond the trailing edge. Tack the front of the boom to the boom former with a bit of CA, leaving some space for it to move around. Hold the fuselage and boom against your template, moving the boom up and down until it is parallel to the extended chord line. Tack the rear in place, pick up the fuselage, sight the boom straight, and finish glue. Final boom lock-down with epoxy (click for full-size image) 5. Turn the fuselage right side up and re-check your right to left alignment. When satisfied that alignment is correct fill in the back of the fuselage around the boom with scrap balsa to form a dam. You now have a space between the boom former and the rear of the fuselage which gets filled with 5 minute epoxy mixed with lots of micro balloons (to keep it light) - this secures the boom to the fuselage. NOTE: Make sure to push this mixture down around the sides of the boom, etc. to get a good bond on the boom. 6. Cut the boom off at 26 ½ - 27 inches from the center former. Add the Wing Saddle and Wing Hold-Down Blocks Adding wing saddle and hatch support (click for full-size image) The wing saddle from the boom former to the center former is doubled on the inside with 1/8 square balsa and thin CA. At this point the wing hold down blocks can be installed. The lower portion of the front hold down is 1/8 light ply and slides up against the bottom of the 1/8 square doublers and against the center former. The upper portion fits between the doublers and is located so the front wing bolt is about ½ inch back from the leading edge. The rear hold down is constructed the same way and is located so the rear wing bolt is located 5 inches from the front one. The upper hatch is made from light 3/32 balsa. A small scrap of balsa may be used to make a locator block for the front of the hatch. For the time being the hatch may be held on with a small drop of thick CA to the center former. This will allow you to shape the hatch along with the rest of the fuselage. Sand and Finish (almost done!) Now it is time to get out the sandpaper and shape to your liking. I like to round the corners pretty hard and make a nice aerodynamic shape. Carefully cut the top hatch loose and remove. When the fuselage is shaped to your liking, the whole thing is covered with a layer of fiberglass cloth (cloth between 3/4 oz and 1.5 oz works fine - 3/4 oz is strong enough to withstand being "piled in" from fairly high up!). Lay the fiberglass over the fuselage and attach it with water based urethane, which acts as the finish as well. Allow this to dry overnight. Don't skip this step - with the layer of fiberglass it is very difficult to damage the fuselage pod, and it doesn't add a significant amount of weight! An easy technique for applying fiberglass is given in this CRRC tech note. Here are alternate instructions for covering the fuselage (from Denny Maize, aka rcsoarnut@aol.com): "When covering the fuselages with glass I clamp the fuse horizontally from the tail boom and upside down. I use a single piece of 3/4 oz cloth draped over the fuse. I use a foam brush to apply the urethane starting on the bottom and working down both sides (you will have to reach in with your scissors from the front and make a couple of slits to go around the nose contours). When I get the sides covered I stop and trim the cloth so that it will overlap on top. Rotate the fuse and work first one side then the other till they are overlapped and you have your first coat on. "I do not make any attempt to blot this first coat, nor do I use spray adhesive as I like to get the saturation and penetration of the wood for strength. On subsequent coats where you are just filling the weave you can blot the excess off. This fuse is so small and light that I feel the good penetration for strength on the first coat is worth a lot more than the millionth of an ounce you might save by skimping here. My fuses weigh from 1 to 1.2 oz with the boom installed so I'm not sure what you would save by skimping. I don't think you will properly wet the cloth and wood with a spray can on the first coat, but, for finish coats it would be fine." Option: tinting water-based polyurethane Drill and Tap Wing Holddowns You may now locate the exact center of the wing center section and place the wing on the fuselage. Drill a 7/64" pilot hole through the front edge of the wing, about 3/4" from the leading edge - also drill through the holddown block and tap the block for 6-32 threads. Open up the hole in the wing to accept a 6-32 screw and install a 6-32 x 1" aluminum or nylon screw. Carefully measure and locate the wing by measuring from tips of center section to the center of the boom - make SURE that when you drill the rear hole the wing is in good alignment (both tips equal distances from the nose or tail. When properly located, drill rear hole exactly 5 inches from front bolt and tap rear block. Open rear hole in wing and install 6-32 x 1" aluminum or nylon rear wing hold down bolt. To keep the wing from being crushed at the bolt locations, make up a couple of "washers" out of 1/16" plywood, about 1/2" in diameter, and glue them to the upper wing surface with thick CA. (These don't need to be round - we cut them 1/2" square and just sand or cut them to be "roughly round"). If you want to be able to finger-tighten and -loosen the wing bolts, cut two 3/8" long sections of arrow shaft, sand the bolt heads until they friction-fit inside the shaft pieces, and then CA the shaft pieces in place. To make the threaded holes stronger, tap them, drip a bit of thin CA into them, wait a bit, and then tap them again. When you want your next wing to match, screw a cut-off screw you pointed into the front hole. Push the wing down on it, making sure that it's straight, then remove the wing and drill up through the dimple mark. Move the cut-off screw to the back hole, hold the front of the wing down with a screw through your new hole, align the wing, and push the back of the wing down against the point. Drill up through this second dimple, add plywood washers, and you're done. Install Throwing Grip(s) Throwing grips are an almost religious topic in the HLG community. Here are the approaches we've seen used for Terminator throwing grips: 320 sandpaper glued to the fuselage sides, and add a brace to keep the fuse from getting crushed and use a "squeeze grip" to throw with (easy to install and use) Install a 3/16" throwing peg at varying locations from the trailing edge to about 1.25" ahead of the trailing edge (some feel this gives the highest throwing power and control, but you do have to be very careful not to pull down during launch or you can fold the wings!) Cut a hole in the fuselage bottom for a throwing hole (a classic approach - requires adding a partial height former for your finger to push against) Reshape the rear of the fuselage so that you end up with a finger-grip using the bottom of the fuselage (with a finger grip area just below the wing trailing edge). (inspired by the Orbiter HLG, provides an easy high power grip while avoiding the possibility of folding wings due to a pull-down during launch - but does require playing with the fuse design a bit) Probably the best thing to do is to talk to your local club members and pick an approach that seems to meet with local approval. Build and Mount the V-Tail The v-tails are of standard balsa construction. Some folks mount the v-tail to the top of the tailboom. These instructions show mounting it under the tail boom. There are a couple of tradeoff's either way: On top of tailboom: Less likely to get damaged from landings, since the tailboom protects the bottom of the "v" Under the tailboom (described here): Allows control horns and linkages to be more streamlined (they don't stick out as much), so the drag profile of the tail is lower. Easier to align. Can be easier to damage, so you might want to put a light coat of glue or light fiberglass along the bottom of the tail "v" joint so that it doesn't get scraped during landings. Here is a dimensioned diagram of the tail surfaces (click for a large image). And here is a diagram showing the angle of the tail "v", as well as an illustration of the control horns and linkages (click for a large image). Here is a picture of what the assembled tail looks like from above (click the thumbnail below for a larger image) Now for the step-by-step instructions (thanks to Dan again for this step-by-step tail construction guide). (Note: there are a lot of specific dimensions given here. Treat these as loose guidelines, any and all of which may be changed.) Cut the tail parts from 1/8" balsa. Use contest grade balsa (4-6 pounds); if not available, use as light as possible. (You can reduce weight by using 3/32 contest balsa with lightening holes, but the results won't be as strong.) Round the leading edge of each stabilizer and the trailing edge of each ruddervator, and bevel the bottom of the front edge of each ruddervator (see the diagram above if this is confusing). You want to join the roots of the two stabilizers at a 110° angle: with an 8" tail, the tips should be 13" apart. Using a long piece of tape between the tips to set this distance, tack the joint with thin CA, fill the bottom crack up with thick CA, and spray with accelerator. Cover the tail components with film (Ultracote Lite Transparent works well). Make sure to leave 1/2" of space on either side of the top of the joint on the stabilizers, so you can glue down the arrow shaft. Leave the edge of the ruddervators closest to the V-joint bare as well; this is where the control horns are glued. Be careful not to warp the tail when shrinking the film. Hold the stabilizer V against the bottom of the arrow shaft, overlapping the last 2 1/8" of the shaft and leaving 7/8" of the joint uncovered. (You may want to add shims at the front between the shaft and the stabilizers; see note below for details.) Tack in place, fill joint with thick CA, and spray with accelerator. Hold two pieces of 1/32" plywood between your fingers. Use scissors to cut both at the same time to approximately 1/2" high or a little less, and 1/2" wide. Taper one or both sides as you wish, and sand both while still holding them. Then drill a 0.040" hole through both. Temporarily tape each ruddervator to its stabilizer with two small pieces of masking tape, one at either end of the hinge. You should have about 1/4" space from the end of each ruddervator to the V-joint, and each ruddervator should be held at neutral. Hold one of the control horns with a pair of needle nose pliers and apply thick CA to the side you want to attach. Hold it against the inside edge of one of the ruddervators while sighting that you are not over center, and spray lightly with kicker with the other hand. Do the same for the other side. (In the radio/balance instructions, you'll run the control cables through the shaft and add Z-bends at the end to match the control horns. After bending the Zs, remove the ruddervators, put the Zs through the control horns, and reattach each ruddervator with hinge tape.) NOTE: We've found that if you add a little negative incidence to the v-tail (rear of the tail a little higher than the front of the v-tail), you'll need less shimming during the tuning phase. In general, we set the rear of the v-tail 1/64-1/32" above the leading edge of the v-tail, although this is really done by eye. "If it looks like it's barely at an angle it's probably about right" (like cooking - sometimes feel counts!). This isn't critical, since you can always add a shim to the LE or TE of the wing as described in the tuning section - and most folks find over time that they like the incidence tuning slightly different anyway. This is another setting that you shouldn't sweat too much - but feel free to put a touch of angle in here if you wish - just make sure to try the shimming experiments discussed in the tuning section regardless of what you do. Install Radio Gear There are many workable ways to install radio gear in the Terminator - what follows is one way that we have found to be easy to install, adjust and balance the ship with. PUSHRODS Rather than using traditional music wire pushrods, we've had great success using Sullivan #507 cables with the yellow sheaths as pushrod supports (these are the stranded cables, normally used for large ship pull-pull installations). You may be a bit concerned about using cables for pushrods. We were concerned too, but they work very well, they are light and they are easy to work with. Here's the trick: Make sure that the longest unsupported run of cable is about 1/2" with the servos in their neutral position. This should leave just enough travel to handle full surface deflection, and with only 1/2" or so unsupported, the cables will not flex in compression. Solder a threaded coupler on the servo end of each cable. The V-Tail end gets a z-bend. Some builders prefer to solder the coupler end first, and then do the z-bend at the tail, while others prefer to do this in the reverse order. Either approach will work fine. Here is a picture of how the v-tail control horns look once everything has been installed: V-Tail control horns with cable linkage (click for full-size image) SERVO INSTALLATION The Terminator fuselage is designed a bit larger than the "hotshot" HLG fuselages to make radio installation easier. If you are using Cirrus CS-20's, CS-21's or another servo of similar size, you will be able to mount the servos either stacked parallel to the bulkhead or in a row parallel to the fuselage sides. Mounting the servos stacked parallel to the bulkhead will allow you more adjustment range of the CG, and will make it easier to reach up front for moving things around, but it's a little trickier to reach in for adjustments. Check the length of your servo arms, and trim the excess arm length so that you attach the pushrods to the hole 9mm from the servo arm pivot point. You will not need more throw, so you can discard any length over this length - it will just make it harder to fit things in if you leave the arms longer! One approach to servo positioning (click for full-size image) V-Tails must have more down travel than up to work correctly. We've found that with CS-20/21 servos, moving the servo arm one 'click' ahead gives the right throw offset. To do this, center the servos with your radio on, and attach the servo arms so that they are at 90 degrees to the fuselage centerline. Then take each servo arm and re-attach it one "click" ahead - so that the arm is one notch closer to the front of the plane - than the normal 90 degree position. If you use a servo arm of the length described above and V-Tail control horns of the length shown on the plans, we've found that setting your transmitter throws to around 100% gives a decent control feel. Remember that V-Tails need more down than up travel, typically 2:1 for down:up travel. You can obtain this either by setting the travel endpoints in your radio or by setting the arm angles on the servo and ruddervator control arms. BATTERY PACK Terminators have flown successfully with either 110 mAH or 150 mAH packs. By moving the pack around, either one can usually result in a balanced ship without nose or tail weight. Balancing The Terminator has a wide balance range. If you are a beginner, try balancing the Terminator about 2.5" - 2.75" from the leading edge of the wing. If you have flown HLG's before, or are used to a more sensitive ship, start with 2.75" - 3" from the leading edge. We use 3" from the leading edge as the "right" balance point for a performance-trimmed ship. If your Terminator is balanced at 3" from the leading edge, and the nose seems to "ride high", then you may need to reduce the wing incidence (add a 1/16" shim under the rear of the wing trailing edge and try again). If the Terminator tends to "tuck" on a very hard launch, try adding a small shim under the leading edge of the wing, or reducing the amount of shim under the trailing edge of the wing. Another possible reason for this behavior is a tail boom that is not rigid enough. Another way to tell if you need to change the incidence is to look at your elevators at the end of a flight. If the neutral position of the tails is slightly down, then you need to shim up the wing trailing edge a bit, and vice-versa if the neutral position is slightly up