The Lanier Explorer 40

 

Lanier was the very first American company to offer Almost-Ready-To-Fly models (ARF) in America. I remember flying an ARF Lanier Trainer back in the late 1960’s. They also produced ARF aerobatic and semi-scale models as well. These first ARFs featured foam wings and “plastic” molded fuselages. They flew very well and could be seen at almost every model airfield in the country.

In fact, many of these models were so good, that they are still available today. I think Lanier calls them “Classic ARF Models” and they fly just as well as they always did. But Lanier’s Explorer 40 Trainer is not one of the original ARFs. Completely modern by anyone’s standards, the Explorer 40 is of all wood construction with modern heat-shrink plastic covering.

 
Photo 1    Photo 2

The rather plain box hides one of the most creative color schemes found in an ARF trainer today. The “cub yellow” background color is enhanced with dark gray, red, blue and black trim. This color scheme proved easy to see on both cloudy and clear days. This is a weak point found in most “white” trainers. The white airframe can sometimes “hide” on a bright, but overcast day. “Severe Clear” conditions can sometimes make the white color stand out too much as the resulting heavy shadows hide all the dark trim colors.

This does not happen with the Explorer 40. The yellow background color is easily seen on bright overcast days as the airframe contrasts well against the bright white background. On cloudless sunny days, the gray trim on the leading edges can still be seen against the yellow background. Besides being practical, this color scheme is about the prettiest we have seen on any ARF trainer. It certainly received a lot of good comments at the field.

 
Photo 3    Photo 4

While ARF “kits” require more work than Ready-To-Fly (RTF) models, ARFs offer the advantage of allowing the modeler to make the radio system and engine selections. ARFs are also far less expensive than RTF models. If the pilot already has a radio system and suitable engine, an ARF is the best choice.

Most (not all) RTF models arrive with a very basic radio system installed. When building an ARF, the pilot can add a more advanced computer radio system that could increase the aircraft’s performance. The same applies to the engine. Many times, the total cost of an ARF equipped with computer radio and hot .45 ball bearing engine is not much greater than a RTF.

The Lanier Explorer 40 is proof. The entire kit, including everything needed to get airborne except radio and engine, is priced at $90.00. This is just about a steal in today’s ARF market. Adding a $110 ball bearing, high-performance .46 size engine and a mid-range, $230 computer radio system makes for one heck of a great performing trainer that costs just $430. This is not much more than the standard RTF prices of $330 to $375. But the better radio and engine have far more “future potential” as the pilot advances in the sport.

Despite its amazing low price, the Lanier Explorer 40 arrives fully equipped with quality components and very complete hardware packages. One nice hardware package feature is that all the Explorer’s parts are packaged according to their function. All the engine mount hardware is in one bag, all the control surface parts in another and so on. This makes building faster and really cuts down on misplaced parts.

Assembling the Lanier Explorer 40

The Wing

Assembling (building?) the Explorer 40 was very much a straight forward process. Even though Lanier provides excellent photo instructions, we are going to use this fine aircraft as a “How-To” Primer on building an ARF. This means detailing some of the construction steps in greater detail than usual. Fortunately, almost no modifications were required so these construction steps will usually apply to all ARFs. The airplane assembled in about twelve hours of pleasant work. All the parts fit well.

  
Photo 5   Photo 6

The first assembly step is to install the ailerons. The explorer uses the same control surface hinging system (photo 5) that is detailed in Sport Aviator’s “Installing Mylar Hinges” article. But before permanently installing the hinges, note that there is a groove and a hole located on the inboard section of each aileron (photo 6). Before installing the ailerons, make sure to put some slow drying epoxy (12 to 30 minute dry-time) inside the holes.

 
Photo 7    Photo 8

The control rods shown in photo 7, and already installed by the factory, have metal ends that fit into these holes. Using epoxy prevents these holes from enlarging because of flight wear. Enlarged aileron control holes are a major cause of aileron flutter, which can quickly damage an aircraft. A good tool for applying the epoxy is a flat toothpick (photos 8 and 9). Also make sure that the control rod end is inside the hole before gluing the hinges in place. As a last insurance against wear damage, put a few drops of thin CA between the aileron and the straight portion of the aileron control rod as shown in photo 10.

    
Photo 9     Photo 10
    
Photo 11   Photo 12

The next wing assembly step is to glue, with epoxy, the wing halves together. Use twelve-minute epoxy for this task. Before gluing, trial fit the two wing halves together as shown in photo 11. The alignment dowel at the trailing edge is factory installed. But the pre-shaped plywood spar is not. After testing that all parts fit and that the spar does not prevent the wing centers from full meeting (it didn’t on this airplane unlike some other ARF models we have built), assemble the tools and parts you will need (Shown in photo 12). There is no time to start finding all this equipment once the epoxy is mixed and starts to cure.

    
Photo 13   Photo 14

Begin by using a new, very sharp modeling knife with a number 11 blade to trim away the covering that overlaps the center section of each wing half (photo 13). The covering, even while very thin, prevents the center sections from fully and completely meeting. Next, carefully measure the plywood spar to find the exact center. The spar’s center should match the “V” formed by the two sides. The spar in Explorer kit used here was perfect. This “V” must be at the exact center of the spar as it forms the wing’s dihedral. Draw a straight line down the spar as shown in photo 14.

    
Photo 15     Photo 16

Place two modeling pins where the centerline meets the spar’s edges as shown in photo 15. Slide the spar into one wing half until the pins rest against the center section. Do not remove the pins at this time. After fitting the spar and pins, remove them and apply epoxy inside the spar slots in each wing half. Be sure to coat the narrow tops and bottoms of each slot as well as the sides. Use the epoxy brush, available in every hobby shop for about 15 cents, for this task. Using the same brush, apply the epoxy to one wing center section as well. Apply an even coat, not too thick but make sure there is enough to transfer to the other wing center section for a firm bond. Put a little epoxy inside the alignment dowel slot as well.

A Special Hint; Do not apply the adhesive to the outside 1/16 in. of the center section. This allows the epoxy to travel as the wing halves are squeezed together but prevents adhesive overflow out onto the visible top and bottom of the wing. Finally, slide the other wing half onto the spar and against the center section. Be sure the center sections fully meet, then tape the wing together with stretched electrical tape or stretched low-tack modeling tape as shown in photo 16.

    
Photo 17    Photo 18

Do this on a straight surface to prevent warps. Since the Explorer 40 has a flat-bottomed wing, it is usually easiest to place one wing half completely flat against the surface. Let the wing half overlap the edge of the surface to allow the aileron control horns and the rear model clamp to clear the surface.

Clamp? Use the modeling clamp at the trailing edge to keep the two wing halves aligned during drying (photo 18). Make sure the leading edge halves are aligned. You may want to use a second clamp to make sure the straight plywood extension halves, (one half shown in photo 17), are tightly joined. This joined straight section positions and secures the wing in place on the fuselage and so must be strong and tight. Allow the wing to cure completely for at least eight hours. Once dry, there is just one more step to go on the wing.

    
Photo 19                                 Photo 20

The final wing assembly step is to install the aileron servo. Since the wing sheeting is just thin balsawood, as in all models, the aileron servo mounting screws need some hardwood for grip strength. The kit contains two 1/8 in. hardwood servo rails for this purpose (photo 19). Use a thin round file (usually called a “rat tail” file) to make a small slot in the middle of one side of each rail (photo 20). This slot allows the rail to clear the “bent” center section formed by the wings dihedral and get a firm bond to each wing half.

Look carefully at photo 19, click on it to enlarge if necessary, and you should see that the dimensions of each servo rail has been traced onto the wing covering opposite each end of the servo cutout. Use a very sharp modeling knife to remove the covering from these areas. Try not to cut through the balsa wood. Glue the wood servo rails onto the wing using 5-minute epoxy.

Photo 21

Position the servo into the open area. Mark the servo mounting holes onto the wood rails. Remove the servo and drill 1/16” holes. Mount the servo in place using the four screws provided with the servo. Once the servo is mounted, gather the control rod parts supplied in the Explorer kit as shown in photo 21. Screw the control rods onto the two clevises until the rod protrudes 3-5 turns out of the plastic sheath. Install one clevis on each aileron control rod.

Connect the aileron servo to the receiver as shown in photo 22. Make sure the receiver is connected to the battery. Turn on the transmitter (extend the antenna as the transmitter will be on for a while) and the receiver. Make sure the servo is centered and the control wheel holes are parallel to the wing’s trailing edge. Use a 6-inch piece of 1/16 in. music wire, available at every hobby shop, and make a Z bend at the end or just a right angle. If you make a right angle, you can use the retaining clips supplied in the kit and pictured in photo 21.

Photo 22

Install the two 6-inch long pieces of music wire into the servo wheel holes. Note: If you want to install aileron differential as explained in the Sport Aviator “Midwest Aero Star Review” then it is best to do it now. Based upon our flying tests discussed later, the Explorer 40 does not need differential but does benefit from it only at very low airspeeds.

Use a modeling clamp to secure the aileron in the neutral position as shown in photo 22 (again, enlarge if necessary to see the clamp). Place the two control wires together and mark both as shown in photo 22. Cut both wires at the mark so that they resemble photo 23. Install two DuBro® solder couplers, also found at every hobby shop, as shown installed on the right control rod in photo 23.

 
Photo 23     Photo 24

Protect the wing covering with a scrap piece of wood. Flux the rod ends, install the solder coupler and solder in place with the radio system still on and the aileron clamped in neutral as described (photo 24). Spray a little water onto the couplers for cooling. This is the easiest way to install firm, near flutter-free ailerons, that are perfectly centered. While this installation was performed on the Lanier Explorer 40, the same technique can be used for all trainer and sport aircraft as well as on rudder and elevator control rods.

 
Photo 25    Photo 26

The Explorer 40 uses the highly recommended bolt on wing system as opposed to rubber bands. For added durability and strength, Lanier provides a reinforcing pad that is installed on the wing’s top section over the boltholes. As with the aileron servo mount rails, cut the wing covering away from the area under the reinforcing pad (photo 25). Use a razor saw to score, not cut through, the underside of the pad as shown in photo 26. Then epoxy the pad in place ensuring that it is firmly attached to both wing halves. The score allows the pad to flex to fit the wing’s dihedral. Drilling from the bottom of the wing, use the wing’s boltholes as a guide to open the holes through the reinforcing pad.

Photo 27

When completed, the mounting reinforcement pad and installed wing will look like photo 27. But for now, we are done with the wing, as it will be mounted later.

 Pinning On The Tail Feathers

Because the Explorer 40 has a flat fuselage bottom, a straight wing and non-airfoil (“sheet”) stabilizer and vertical fin, installing the tail surfaces is easy. Just make sure they are installed straight. The location of the two rear “wings”, stabilizer and vertical fin, does affect flight performance. It is vital to install the stabilizer so that it is exactly parallel to the wings. If the stabilizer is canted, one tip higher than the other, in relation to the wing, then elevator input will also have a roll effect.

For example, if the left stabilizer tip is low and the right tip high, up elevator will also induce a roll to the left. This makes flying, and especially, landing, very difficult as the pilot must also hold opposite ailerons to stop the roll while doing everything else necessary to land. This is true of any aircraft. The Explorer 40 is more resistant to such misalignments as the wing is very large and has a generous dihedral angle. Still, it is better to get things straight than to depend on the Explorer’s stable flight characteristics.

 
Photo 28     Photo 29

Use a large straight edge and mark the exact middle of the stabilizer (photo 28). Then, use a square to draw a center line on the stab (photo 29). Measure the middle of the rear fuselage and put a mark. Install the stabilizer all the way forward and align the two center marks as shown in photo 28. Pin the stabilizer in place with a large modeling pin. Find and mark the center point of the fuselage just forward of the wing. Place a pin at this point (photo 31).

 
Photo 30   Photo 31

Measure the distance from each stabilizer tip to the pin at the front of the wing saddle (photo 32). Once these distances match, the stabilizer will be centered in the fuselage and parallel to the wing. Use a thin felt tip marker and trace the fuselage outline on the stabilizer as shown in photo 33.

 
Photo 32     Photo 33

Remove the stabilizer from the fuselage. Place a straight edge 1/16 in. inside the fuselage outline. This allows the covering to be held inside the fuselage once the stabilizer is installed. Use a new No. 11 blade and carefully cut the covering (photo 34). Do not cut into the wood as this could weaken it. Then carefully peel back the covering as shown in photo 35. Adhesives do not adhere to plastic coverings well. While CAA glues might stick, the adhesion will be only to the covering which is not firmly bonded to the wood enough to withstand flight loads. Always remove the covering before gluing.

 

Photo 34    Photo 35

Before permanently installing the stabilizer, it is a good idea to install the elevator and rudder control rods (photo 36). It is easier to get these rods in place now, for any aircraft, than to try bending them around corners with the tail feathers blocking interior access. Only the rods need to be installed, the control hardware can be added later. Tape the rods in place inside the fuselage (photo 37) to prevent their slipping away during the tail feather installation.

 
Photo 36    Photo 37

After all the preparation, the actual stabilizer installation is pretty straight forward. Place low-tack masking tape around both sides of the stabilizer mounting slot (photo 38) to protect the fuselage covering from excess adhesive. Do the same just outside the fuselage trace lines on the stabilizer. Brush some 30-minute epoxy into the fuselage slots. Weight the fuselage onto a level surface as shown in photo 39. Slide the stabilizer into the fuselage and re-center as previously described.

 
Photo 38    Photo 39

Remove any excess epoxy from the fuselage sides and the stabilizer. Remove the masking tape without disturbing the stabilizer’s position. Make sure the fuselage is level, notice the level in photo 39 at the rear of the wing saddle, and then use a spacer to insure the stabilizer is also level. The explorer’s flat-bottomed wing makes this process easy. Tack glue the stabilizer in place with a few drops of thin CAA (photo 41) and rest until the epoxy cures.

 
Photo 40    Photo 41

 

 

This construction method will be used throughout your model building career. Things may get more difficult as fuselages start to taper and wings are not flat-bottomed, but the principles remain the same. It usually requires just about 30 minutes to complete the installation and insures the stabilizer is always correctly installed.

 
Photo 42    Photo 43

The vertical fin is next. Protect the fuselage as before (photo 42) and remove the covering to within 1/16 in. of the fuselage top. Brush 12 –minute epoxy onto the bottom of the vertical fin and into the fuselage slot. Position the vertical fin in place and be sure that it is vertical to the stabilizer using a modeling triangle designed for this purpose (photo 43). Note the cutout in the triangle designed to clear the fuselage sides.

Engine Mount and Radio Installation

Installing the onboard radio system into the Explorer is easy. The servo tray is factory mounted into the fuselage. Just for durability, you may want to glue 1/8 x ½ in. servo mount reinforcing strips as shown in photo 44. While not really necessary, these strips provide extra servo support and more gripping surface for the servo screws.

Photo 44

First, install the elevator halves and rudder as described in “Installing Mylar Hinges” Then install the elevator and rudder control rod horns making sure the control rods run in a straight line. Screw a clevis onto each of the installed control rods until the treads protrude about 1/8 in. past the clevis sleeve (photo 45). Attach a control horn to the clevis and position it on the elevator. Make sure that the clevis pin is exactly centered over the elevator to stabilizer joint. Do this on both sides. Mark the screw holes, drill 1/16 in. holes and mount the control horns (photo 46). Do the same for the rudder.

 
Photo 45    Photo 46

Mount the three fuselage servos. The front servo is the throttle servo. As shown in photo 47, use the solder method described for the aileron installation to ensure that the control surfaces are in neutral. Measure the elevator movement of each half to ensure that they both move the same amount for a given control input. Lanier’s control horns are nearly infinitely adjustable to allow perfect synchronization.

Photo 47

Both elevator halves must have identical movements or the aircraft will respond to elevator inputs just as if the stabilizer was tilted. It will roll slightly towards the elevator half with the most movement. Set one elevator half to move as directed in the instructions. Then adjust the other half to match its movements. If the second elevator half has greater movement than the first, screw the control horn coupler away from the elevator. Reverse for too little movement.

 

Having split elevator halves allows the pilot to adjust for a slightly titled stabilizer. If the left side stabilizer tip is low, seen from the rear, then adjust that half to move slightly, about 2-4%, less than the other side. Known as the “Law of Compensating Errors”, this process can restore straight and level flight to an aircraft built slightly off. But it is always better to build it right in the first place.

 
Photo 48    Photo 49

To install the engine, you will need to construct a vertical jig like the one in the photos. You will use this jig for the next hundred years on every model you build, so take your time constructing it. Use two pieces of ¾ in. plywood. The Explorer 40 uses the common split fiberglass engine mount. This style mount requires just a little more work than the adjustable mounts. Lanier provides the usual engine mounting screws that will work. But there is a better method to attach an engine.

 

Attach one side to the jig. Make sure the mount is vertical. Clamp the engine in place, in photo 48 a venerable Super Tiger Bull ring 40, the proper distance from the rear of the jig (firewall). Using a hole locator, either from Great Planes or Harry Higley, mark the two mount holes (photo 49). Remove the engine. If you have a drill press, drill the holes with the proper size drill for a 6-32 tap. If no drill press is available, try to drill the holes, as straight as possible. Drill one hole at a time then test fit the engine before drilling the next hole,

 
Photo 50    Photo 51

Tap the two holes for a 6-32 bolt (photo 50) and use two 1 ¼ in. socket head bolts, available in any hobby shop, to mount the engine to the first half. Clamp the engine to the second motor mount half as shown in photo 51. Use a small triangle to make sure the engine is straight on the second mount half (photo 51). Then mark, drill, and tap the second pair of holes. Use a modeling knife with a chisel blade to remove the upraised crown from the holes before final engine mounting (photo 52).

 
Photo 52                   Photo 53

Install the nose gear bearings before putting the engine/mount assembly in place. The holes for these blocks are marked on the firewall as are the centerline and the engine mount holes (photo 54). Use the nose gear to align the two mounting blocks (photo 53) as they are installed with the supplied mounting screws. This prevents binding that could slow the rudder response as ground steering is done by the rudder servo. After mounting the blocks, remove them and strengthen the screw treads with thin CAA (photo 55).

 
Photo 54               Photo 55

It just may be that the mount’s firewall bolt holes match those marked on the firewall, but probably not. Position the engine/mount assembly centered as much as possible within the marked holes. Drill one of the four firewall holes and use a 6-32 bolt and blind nut to mount the assembly. Photo 56 is an enlarged version of photo 55 showing the blind nuts for the engine mount. Fortunately the fuselage is large enough that it is easy to get your hands inside to install the nuts. Then level the fuselage and the engine/mount assembly as shown in photo 57. Drill the remaining holes and install the bolts and blind nuts.

 
Photo 56      Photo 57

Hooking up the nose wheel steering is easy. Just be sure that there is not too much steering. The nose wheel should only turn about 15 degrees in each direction. More than that will make takeoffs difficult to manage. If necessary, move the steering arm inwards on the servo wheel to reduce movement.

 
Photo 58    Photo 59

Install the throttle control rod. One easy way to insure the engine will respond exactly as you need is to connect the throttle servo to the receiver. Advance the throttle and throttle trim to maximum. Set the engine’s throttle arm on full throttle (photo 58). Make the throttle rod from two separate pieces. One piece is the threaded rod supplied in the kit, the other a piece of 1/16 in. music wire. Use a z-bend at the servo or an adjustable servo connector on the music wire. Solder assemble just like the ailerons (photo 59). This ensures full throttle is always available.

Having full throttle is important, but not just for the reason many pilots think. While it is nice to have full power there when you need it, the Explorer 40 will takeoff with less than full power if needed. Full power is important when setting the high-speed needle valve. If the needle is set when the engine is producing only 90% power, the setting could be too lean. This could cause engine damage.

Photo 60

Lanier provides everything needed for fuel tank installation. Assemble the tank as per instructions and place it inside the fuselage so that the stopper area protrudes from the firewall hole. Make sure the fittings are tight. Check the Model Aviation article reprint in the Pri-Fly section of Sport Aviator, “Support Your Local Engine” for tank assembly and installation details.

 
Photo 61    Photo 62

Wrap the receiver battery in thin foam as shown in photos 61 and 62. Do not use rubber bands to hold the foam in place. Rubber bands compress the foam reducing its shock absorbing qualities. Use masking tape instead. Since the battery is positioned under the fuel tank, enclosing it in a plastic bag is a good idea. Seal the wire exit with silicone bath caulk. Once in position inside the fuselage, hold both the fuel tank and the battery in place with some extra foam (photo 63). Make sure the battery lead is exposed.

Photo 63
 
Photo 64       Photo 65

It may be possible that the muffler on your engine does not fit in the space allowed. This is very common on most ARFs. Here’s how to fix it. Using a modeling knife, gently peal back the covering and mark the wood to be removed to allow the muffler to fit (photo 64). Remove the excess wood and gently fold the bottom covering back in place (photo 65). Use a plastic covering trim iron is available. Otherwise, use thin CAA but don’t glue your fingers here. It is too close to the prop!

 
Photo 66    Photo 67

Then fold over the top section and seal, or glue, in place (photo 67). The final product, photo 67, looks like it came that way from the manufacturer.

 

Photo 68

There are just a few things left to do. First, install the wing. Lanier did all the aligning. The wing bolt blind nuts are already installed in the fuselage. The wing assembly forms the front wing hold down and its matching slot is factory cut. Working from the bottom, extend the wing bolt holes through the top reinforcing block. Install the wing and then check the alignment.

Measure from the inside front corner of the wing’s aileron slots, on both sides, (Photo 68) to the center of the vertical fin. Both measurements should match. The wing was off by less than 1/64 in. on this Explorer 40. That is more than exact enough for a trainer or a sport aircraft. In fact, it is pretty good for anything but a Precision Aerobatic (Pattern) airplane. Most ARFs are not this exact.

If the wing was more than 1/8 in. off then the mounting holes would have to be enlarged, the wing repositioned, brass sleeves with an inside diameter matching the wing bolt’s outside diameter inserted into the large wing holes and then the sleeves glued in place once the wing was properly aligned. Fortunately Lanier pays attention to such details and that grueling task was not necessary.

 
Photo 69     Photo 70

The last assembly step is to install the main landing gear. All ARFs that use fuselage mounted wire landing gear have the same arrangement. A short section of the wire gear slides into a hole in the fuselage while another section rests inside a slot in the bottom. While the holes are pre-drilled in the fuselage, the landing gear makes a radius turn while the hole is vertical. This means that the wire gear cannot fully fit into the fuselage slot.

Look carefully at photo 69 and you will note that a small amount of wood has been removed to allow the gear’s radius to clear the fuselage bottom. This allows the gear to lay completely flat against the fuselage bottom inside the slot (photo 70). This arrangement not only provides extra strength but looks better.

Photo 71

As mentioned before, the entire assembly process took twelve hours to complete. For this effort, we have a great and different looking Basic RC Trainer. But as good as it looks and as easy as it was to build, how does the darn thing fly? Good question.

For the record, it flies very well. But it also has some unique flying characteristics not found in most trainers. In fact, since the Explorer 40‘s flying ability is so interesting and this article is so long, look for the detailed flight report, “Explorer 40 Goes Flying” in the Test Pilot’s report section.

Q

For more information regarding the Lanier Explorer, click here.

Short URL: http://masportaviator.com/?p=163