Hobby Lobby Telemaster Electro ARF

 

 

When the German-designed Senior Telemaster first appeared in the mid-1970’s it was a real sensation in the RC modeling world. At this time, the most common larger RC airplanes had wingspans around six feet, weighed about 7-8 pounds and were powered by .60 cu. in. engines. The Senior Telemaster featured an eight-foot long wing and a fuselage to match.

This was a large airplane, one of the biggest available and it was a kit! The few larger airplanes available had to be “scratch built” from plans. The builder had to make all the kit parts before even beginning construction. But size alone was not what made the Senior Telemaster so famous.

The Senior Telemaster was a special airplane in many ways. Yes, it was big. But it was also very light. Instead of the solid balsa fuselage sides so common then, this airplane was built mostly from “sticks” assembled on a flat board. The vertical fin, rudder and horizontal stabilizer were also built up, not made from large balsa sheets. Covered in plastic covering, most Senior Telemasters weighed around nine pounds. Any of the “sixty” engines of the day could pull this monster into some respectable climbs. Put one of the few larger engines, like the Fox 78, on the front and “watch out clouds, we’re coming through!”

Most sport airplanes in those days had balsa sheet stabilizers. These stabilizers did not do all that much “lifting” as they were more stabilizer than lifting surface. The Senior Telemaster had a flat bottom airfoil to match its giant flat bottom wing. If memory serves, the 96 in. wing had a chord, width, around 14 inches. When this ~1,350 square inch wing was combined with the lifting stabilizer, the Senior Telemaster had well over 1,500 sq. in. of lifting surface.

Combined with its generous dihedral and large control surfaces, this enormous lifting power made the Senior Telemaster a joy to fly. If you landed a Senior Telemaster at greater than walking speeds, you were just showing off. Did I mention that the Senior Telemaster also had flaps? Well, It did and with flaps deployed, the airplane could be hovered to a landing in any wind over ten miles per hour. The Senior Telemaster might have been the first kit-built model to “Harrier Land” 30 years before 3-D flying was “invented.”

The Senior Telemaster not only became a popular sport airplane, but also was one of the best basic trainers available. No one could fault the Telemaster’s excellent basic trainer flying abilities. It flew slowly, was totally honest, withstood piloting abuse that would leave “passengers” (and even some instructors still on the ground) deep in their airsick bags without complaint and was easy to see even high in the sky. The pilot’s workload was extremely low.

But the Telemaster had one problem as a basic trainer. It’s stick construction made it harder to build than the more common basic trainers. Building a Senior Telemaster took about twice as long as building a basic trainer, required a bigger building area and some special building skills to line up all those “sticks”. This limited the Senior Telemaster’s popularity as a basic trainer.

Even so, the Senior Telemaster proved so popular that other sizes were soon offered. Every size from a small, .10-sized, airplane up to a 12-foot monster was kitted. The 40-size version with a six-foot wingspan became very popular but was still harder to build than most sport airplanes of the day.

Of course, building difficulty is not a problem in today’s modeling world. Almost-Ready-to-Fly (ARF) airplanes mean that the factory does the difficult building part while the pilot just assembles the airframe adding engine, radio and fuel system components. Hobby Lobby began offering an ARF Senior Telemaster a few years ago and it has proven even more popular than the original kit version.

Ever on the forefront of electric-powered model flight, Hobby Lobby has introduced an Electric-powered ARF Telemaster, the Telemaster Electro. (Don’t blame me if the name sounds like it comes from an old Sci-Fi movie, I just report these things, not make them up.) The Telemaster Electro is a beautifully built and covered version of the popular 40-size Telemaster.

 

 

Photo 1              Photo 2

The Telemaster Electro arrives well packed in a colorful box. Despite UPS’s doing its best to mangle the outside shipping box, the contents were safe and cozy inside the kit box. The outside box resembled the remnants of a shotgun target but there was no damage at all to the airplane components and just a few dents in the inner box. The main airframe components are shown in photo 2. The transparent red covering does not photograph well, but it is impressive in person. One surprise was that this is one of the very few airplanes we have received that required no wrinkle removal; none. Despite shipping, construction and flying, this airplane never saw either a heat iron or gun for wrinkle repair. The covering was tight and wrinkle-free everywhere.

 

 

Photo 3          Photo 4

The kit also includes a lot of hardware. There are separate wood parts that are added during construction, including a sub-fin that is totally unidentified in the instructions.  Light weight wheels and axles are also included. This kit offers a flap option but does not include the hardware required to make the flaps work.

Photo 4 shows the electrical equipment required to make the Telemaster fly. The motor is the famous AXI outrunner, here a 28-26-12, managed by a 40-amp JETI Speed Controller with Battery Eliminator Circuitry (BEC). The JETI is programmable using the “card” shown in the photo. Brake settings, motor type and battery cutoff voltages can be set by the pilot.

Building the ARF Telemaster Electro – The Wing

The only real decision the builder (assembler?) needs to make is to flap or not to flap. All the larger Telemasters had provisions for wing flaps. The original Senior Telemaster kit always came with flaps. Understand that the Telemaster series does not need flaps to perform well or to land slowly. Even without wing flaps, no Telemaster ever needed to land faster than about 20 mph while the Senior Telemaster could probably land backwards in a 10 mph headwind.

But the wing flaps added to the airplane’s appeal. The extra wing lift the flaps provided allowed the Telemaster to land at less than 10 mph. Having flaps also expanded the number of airfields the big aircraft could use. With full flaps and in a full sideslip, the Senior Telemaster could descend almost vertically into a small, tree-lined field without gaining airspeed. Even from several hundred feet up, it is possible to land the Telemaster in about 50 feet of runway using only about 100 ft. of clear approach space. A new pilot should never consider doing this, but an experienced one can accomplish this, if necessary, by slipping the flapped Telemaster.

Considering that the Telemaster Electro, which uses quiet electric power instead of a glow engine, greatly expands the number of airfield possibilities, having flaps seems a natural choice. While this big airplane can never be considered a “Park Flyer” its excellent rate of climb and small field ability using flaps, lets the pilot use almost any safe open spot for an airfield, even a park.

 

 

Photo 5            Photo 6

Therefore, this Telemaster Electro will have operating wing flaps. There is no extra hardware for flap operation so you will have to purchase the control horns and rods plus two clevises. That totals about $7.00 plus two more servos, about $24.00 for Hitec HS 322 HD’s. But the kit makes installing flaps easier by partially cutting the flaps out of the wing’s trailing edge. The partial cut is covered by the transparent red covering material for those pilots who do not wish to install the flaps. But the partial cut is easily seen under the transparent covering.

Make a mark 2 5/8 in. from the wing center as shown in photo 5. Do this on the top and on the bottom of the wing. Use a square placed against the wing trailing edge to draw a line perpendicular to the T.E. at this point. Again, mark both the wing top and bottom. Protect the wing as shown in photo 6 with a scrap piece of balsa wood. Using a sharp, and straight, razor saw, cut along the line on both sides.

 

 

Photo 7            Photo 8

Use a metal straight edge along the partially cutout flap to guide a sharp modeling razor knife when cutting out the flap from the trailing edge. Do the same on the top of the wing. The end result will look like photo 8. Then do the other wing.

 

 

Photo 9          Photo 10

Carefully cut the covering along what had been the “outside” edge of the flap as shown in photo 9. Then gently peel the covering away from the flap’s leading edge as shown in photo 10. Make a straight line on the bottom of the flap about 1/2 inch in from the flap’s leading edge.

 

 

Photo 11         Photo 12

Use a modeling razor plane or a sanding block to remove the wood from the top leading edge back to the line you made on the bottom of the flap (photo 11). Make sure not to remove any material from the top leading edge of the flap. Use a long sanding block to do the final shaping and finishing (photo 12). If you are not careful here, you might be making the first steps toward assembling some modeling wood working tools and someday building a wood kit! That could be a fate too terrible to contemplate! (I am only kidding here.)

Photo 13

The final flap should look like photo 13. Re-iron the covering onto the flap bottom and cover the new leading edge with the excess part. This covering is a low-temperature type. Set your iron for around 225 degrees F.

 

 

Photo 14      Photo 15

Cutting out the flap leaves the wing’s new trailing edge and inside section uncovered. Since the Telemaster is electric powered, this is not a handicap as there is no engine residue to damage the wood. Still, it somehow offends my very old fashioned modeling instincts. Since I am getting too old in this sport, almost 37 years, to allow my sensibilities to be offended, I covered this area as shown in photo 14.

I used Missile Red TopFlite Monokote™ for this job. The color is not an exact match but it is close. Photo 14 seems to show a large color difference but this is a photo effect only. Photo 15, installing the Mylar® hinges, shows how close in color the two coverings really are. Make sure no to overlap the Monokote onto either the top or bottom of the wing to hide any color difference. Cover just the trailing edge and the inside bare wood edge of the wing.

Photo 15 also shows that the manufacturer has made provisions for mounting the flap servo in each wing half. Before installing the hinges, read the Sport Aviator Flight-Tech article, Installing Mylar Hinges. Hinge the flap in place positioning the hinges at the top of the trailing edge as shown in photo 15. Do not install the hinges in the middle of the trailing edge as you will do for the ailerons. Since the flap will mostly deflect downwards, the top mounted hinges allow for the most flap movement.

 

 

Photo 17         Photo 18

Before marking the wing and flap for the hinge installation, put a spacer in between the wing overhang and the inside of the flap as shown in photo 17. A piece of thin cardboard stock, here from the Jeti Speed Controller package, is good enough. You are only making sure there is a little clearance to permit the flap to move freely. Position the hinges and insert some small pins in place to make sure each hinge extends halfway into both sides (photo 17).

Remove the pins and press the flap fully into the wing’s trailing edge. Then fix in place using thin CAA as shown in the article linked above. Install the aileron, the hinge slots are factory installed in the middle of the wing’s trailing edge. The final wing half should look like photo 18. Put it aside and make the other wing half look like this as well. You have now completed about 40% of the construction work.

 

 

Photo 19       Photo 20

As do most ARF aircraft today, the Telemaster Electro uses a laminated spar to increase wing strength and lower the airplane’s weight. Position the three 1/16th in. spars and make sure they are square. Photo 19 shows this squaring process using a metal sanding block and a thick combination square. Apply 12 –minute dry epoxy to all mating surfaces, realign and clamp in place.

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Building the ARF Telemaster Electro – The Fuselage

Photo 30

The Telemaster Electro uses standard ARF construction for the fuselage. Almost all the work is done at the factory. About all the “builder” has left to do is to install the tail feathers and landing gear plus the radio and power systems.

In my very short electric building career, I have learned that installing the power system first is a good idea. The fuselage gets turned over a lot during motor and speed controller installation. This is better done without the stabilizer and vertical fin in place.

The Telemaster Electro is designed for the AXI 28/26/12 outrunner motor. Outrunner means that the propeller is bolted to the motor case and the entire case revolves around the center “crankshaft”. This is much like the old WW I rotary engines but does not have their miserable effects on the airplane’s flight (try making a right turn in a Camel at all or a sharp left turn without spinning; not easy to do the first few times).

 

 

Photo 31          Photo 31A

This motor configuration provides extra horsepower and seems to run cooler. Fortunately, cooling is not a factor in the Telemaster as the motor and speed controller are completely exposed to the air stream. Notice in photo 31 that the motor is mounted in the reverse position. The usual mounting method, shown on the Black Horse Models’ Liberty in photo 31A, is to bolt the front, non-rotating, part of the motor to a forward firewall. But the PM 282002 motor mount system moves the non-rotating part of the motor to the rear. The rotating case is now in the front and a propeller adaptor bolts to the entire case.

 

 

Photo 32          Photo 33

The blind nuts in the firewall, set to fit the PM 282002 mount, are factory installed. Put some removable thread locking compound into the nuts (photo 32). There is a wheel collar that goes onto the rotating rear shaft and fits inside the motor mount next to the firewall (photo 34). Be sure to install this as the collar acts as a vibration dampener.

 

 

Photo 34         Photo 35

In short make the motor look like photo 35. One note to remember, the kit comes with a complete set of hardware and screws. But you can’t use the bolts provided in the kit to mount the motor/mount assembly to the firewall. The bolt heads interfere with the rotating motor case if you do. Instead, use 4-40 Allen head socket bolts (note photo 33 closely).

Install the Jeti 40-amp speed controller in the slot just under and to the right of the motor (photo 33). There is no way this installation can ever overheat.

 

Photo 36

Test-install the propeller but remove it for the rest of the construction process. Hook up the red and black motor wires backwards (photo 36). The white wire is connected to the controllers white wire. If the motor turns the wrong way, reverse the red and black wires.

 

 

Photo 37       Photo 38

The stabilizer mount area on the fuselage already has the covering removed. But this is a large stabilizer and a narrow fuselage. Therefore, you need to install the factory covered triangle braces to increase the gluing surface. Place a brace against one fuselage side, trace it on the covering. Then cut just inside the lines to remove the covering (photo 38). It is best to use the Great Planes “Hot Knife” for this task.

 

 

Photo 39

The end result should look like photo 39. Insure that both triangle reinforcers are exactly even with the fuselage mounting area. If not, level them with light sanding.

 

 

Photo 40     Photo 41

Use a model covering iron to firmly adhere the covering over the control rod exit slots (photo 40). Cut away the covering and adhere it to the inside of the slots. Under the slot, there is an outside tube for the control rod (photo 41). Bring each control rod sheath to the outside of the fuselage as shown in photo 38. Do this now as it is very hard to get those sheaths outside the fuselage once the stabilizer is installed.

 

 

Photo 42         Photo 43

Position the stabilizer on the fuselage. Center it exactly and then measure from each stabilizer tip to a pin located in the exact center of the fuselage at the wing’s trailing edge. This spot is factory marked for later wing alignment but you can use the mark to center the pin as well. Once the stabilizer is properly aligned, mark where it meets the fuselage on the bottom. Use the Hot Knife to remove the covering from the bottom of the stabilizer just inside the marks (photo 42). Do not remove any covering from the stabilizer top at this time.

Photo 43A

Level the fuselage as shown in photo 43. Make sure the stabilizer’s mounting area is exactly level with the wing saddle. Sand if required. The stabilizer must be exactly parallel with the wing. If not, there will be an unwanted rolling moment every time the elevator moves. Once everything is set, apply 30 minute epoxy to the mount, position the stab in place and align it again. Allow to dry. Then install the elevator hinges into the pre-cut slots and install the elevator as you did the ailerons and flaps.

 

 

Photo 44         Photo 45

Photo 44 shows the entire tail wheel assembly. All the holes, including the two for mounting the plastic pins, are factory cut into the fuselage (photo 45). There is a lot of work pre-done on this airplane that really shortens the building time.

 

Photo 46

Mount the tail wheel in place now. You may also want to take this opportunity to hook up the elevator control rod. That is always easier to do without the vertical fin in place. But the tail wheel must be mounted before installing the rudder since one end is inserted into the rudder for steering control.

 

 

Photo 47          Photo 48

Cut out only the two slots on the top of the stabilizer. Adhere the covering into the slots on the side about 1/16 inch. Put low-tack masking tape on each side of the slots. Position the vertical fin in place and mark the covering just where it exits the stabilizer. If necessary, cut away the covering just below the mark (photo 48).

 

 

Photo 49          Photo 50

Brush 5-minute or 12-minute dry epoxy into the slots. Insert the vertical fin into the slots. Remove the tape. Use a triangle square to insure that the fin is perpendicular to the stabilizer (photo 50).

Once dry, put some 30-minute epoxy into the rudder slot, and into the groove. Install the rudder as you did the other control surfaces. Make sure there is epoxy on the slot and in the hole. The adhesive strengthens the soft balsa against all the “ground pounding” it will be receiving while it performs its steering chores.

Photo 51

Install the two servos into the fuselage. The kit provides two nylon inner rods to connect the servos to the elevator and rudder. The rudder servo in photo 51 shows one of these rods. Center the rudder and glue the threaded clevis end inside the yellow rod using epoxy. Install a clevis and slide the rod through the outer tube and into the servo compartment. Clamp the rudder straight and thread the “Z” bend rod into the yellow rod until it will fit into the servo arm, which you have centered using the transmitter, without either stretching of bending. Let the epoxy dry.

I used a metal rod for elevator control since some nylon rods are temperature sensitive. They expand in the heat and contract in cooler weather. This means the elevator trim changes constantly.

 

 

Photo 52                                    Photo 53

There are three small pieces of oddly shaped plywood included in the kit (photo 52). But just like the covered and shaped sub fin (also in photo 52) the otherwise excellent instruction booklet seems to be silent. At least I could find no mention of these items. I never did use the sub fin as it would have interfered with the tail wheel. But those three little plywood pieces are important. As photo 53 shows, these pieces form the rear stop for the battery. Epoxy them together as shown. Then fit your batte

At The Field And In The Air

 

 

Photo 56         Photo 57

The Telemaster series has always been an attractive airplane. The opaque white trim sets off the transparent red covering. There is a lot of wing on this airplane. Actually, there is even more wing than it at first would appear. Notice that the stabilizer is also an airfoil. Unlike balsa sheet stabilizers, this one provides extra lift. This has two advantages. First, the extra lift adds to that of the wing, making for an even better flying airplane. Second, the “lifting stab” allows the Telemaster to be more tolerant of CG ranges. My own opinion, after having added lifting stabilizers to my own designs, is that the Telemaster’s airfoil stabilizer is one of the secrets behind this airplane’s 30 year success story. Hobby Lobby kept this new Telemaster true to its heritage by not opting for the cheaper sheet stabilizer.

 

Photo 58

The Telemaster front end has always been unique. Taking away the large glow engine and protruding muffler really shows that the airplane’s front is more streamlined than it appears in the glow version. The battery hatch on the forward top side features a unique latching system – a magnet. The top clips under the “windshield” and is held down in front by a powerful magnet. To change the battery, just lift the front edge to remove the hatch. Replace the battery then hook the top rear of the hatch under the windshield again and drop the front edge in place. This is easy.

 

Photo 59

Taxiing out for the first takeoff proved that this Telemaster handles as well on the ground as did all its ancestors. The tail is long allowing effective steering without the annoying fuselage swings so common to Cub-like tail wheel aircraft whose tail wheels are closer to the wing. The main gear is wide spread for even better stability. The extra stability remains during the takeoff run as well.

The AXI motor has plenty of power. It turns the APC 13 x 8 inch Electric propeller at 6,700 rpm while drawing just 31.0 amps. The Telemaster, without flaps deployed, rolled about 20 feet and then jumped up from the ground. The airplane held a 45 degree, or so, climb angle for the first 150 feet and then had to be leveled out as the airspeed dropped too low. “Too low” didn’t happen until the airspeed was well under 10 mph.

 

Photo 60

But even then, the Telemaster held a straight line and was easily controlled using just the ailerons and elevator. Most airplanes at this low speed would need rudder inputs to stay straight but that was not happening here. Part of this unusual low-speed aileron control is due to the airplane’s design, its long tail moment and effective vertical fin area, but part is due to the mechanical aileron differential installed during the building.

 

Photo 61

The Telemaster has large ailerons located far out on a flat-bottom wing. That is another way of saying Adverse Yaw. Adverse yaw occurs because the downward moving aileron enters the denser air stream flowing under the wing while the upwards moving aileron moves into less dense air. Therefore, the downward aileron generates more drag and this excess drag pulls the airplane’s nose towards the down aileron.

This is a problem only because a left bank, “left” aileron, means the right side aileron is the one moving downwards. The higher drag is therefore on the right side and this pulls the aircraft’s nose to the right while the pilot is trying to make a left turn. Flat-bottom wings exhibit the greatest amount of adverse yaw because the air density difference is greatest with these airfoils and because ailerons are the least effective on such wings. (There are reasons for this but that is not important here.)

While hooking up the Telemaster’s ailerons, I induced some asymmetrical aileron movement into the linkage design. Note in photo 61 that the servo arm is not centered. Instead, the neutral point is biased away from the aileron. The result is that the aileron moves further upwards than it will move downwards. This equalizes the aileron drag, reducing the downward drag component while increasing the upward moving aileron’s drag.

If you have only an analog transmitter, be sure to put at least this much aileron differential into the ailerons, maybe just slightly more. If you are using a computer transmitter and have the ailerons on different channels, you can just use the transmitter’s aileron differential settings. Although the Telemaster’s transmitter is the new JR 6103 computer system, the ailerons are on a “Y” cord. This precludes using transmitter differential.

 

 

Photo 62       Photo 63

Fly-bys for the camera were a joy to watch. The airplane passes by at about 20 mph, its low cruise speed. This is with flaps up and into a cross wind. The airplane is fully controllable and lets the pilot think so far ahead that it is tempting to take mental breaks during the flight. Slow speed handling is better than ideal and the airplane always remains responsive.

 

 

Photo 64        Photo 65

But a model airplane’s life is not destined always for straight and level flight. The Telemaster knows this and can perform most basic aerobatics with stately grace. Since this airplane has lots of power, loops can be as large as 125 ft. in diameter. Climb rate is good and the Telemaster can manage a 100 ft. vertical climb from cruise. 100 vertical feet is more than enough to do a good stall turn and the Telemaster does. Since the airplane is so longitudinally stable (a long fuselage and big vertical fin area) the pilot will need to keep some power on during the first part of the turn to insure the airplane goes “over the top” without sliding backwards.

Single and multiple rolls are great. The aircraft performs a single roll in about 3 seconds. Raising the nose prior to the roll is not necessary as long as the pilot remembers to input a lot of down elevator while inverted. Inverted flight requires about 60% of the available down elevator. Inverted turns take up about all the remaining elevator movement. Outside loops are not the Telemaster’s forte and the airplane must be forced intro by diving a few hundred feet before pushing up into the loop.

Spins just don’t happen with this airplane without power. Once either power or up elevator is released, the spin stops immediately. Even repeated deep stalls, continuing to hold full up elevator with the motor idling even after the stall break, are non events. Most sport airplanes will become “snappy” in a deep stall and try to fall off on one of the wings. Good basic trainers will keep their wings level in a deep stall but will constantly oscillate between flying and performing another stall pitch up (called Phugoid oscillations).

But the Telemaster does something even better. It just sits there with its nose up in the air, moving forward about 5 mph, while slowly sinking about 2-300 ft. per minute. The wings stay level, the ailerons work (a little anyway) and the rudder remains very effective. If I didn’t know that the Telemaster doesn’t have enough elevator movement to perform a Harrier Landing (level vertical descent to a landing), I would say its deep stall was a 3-D Harrier approach!

To Be a Trainer or Not to Be a Trainer?

 

 

Photo 66        Photo 67

It is hard to actually tell someone just what a good basic trainer this sport airplane really can be. Perhaps the videos will illustrate the point better than words. But, just look at the Telemaster on final approach in photo 66. Even this still photo conveys the aircraft’s stability, slow speed handling and low pilot workload. It just looks right during the approach.

  

 

Photo 68            Photo 69

Even setting up for a one-wheel crosswind landing photographs like a non-event. The airplane goes where you put it with no fuss. Airspeed is slow enough, even in cruise, to allow the new pilot to think ahead of the airplane. Getting the Telemaster to actually stop flying is sometimes more work than just letting it go ahead and land itself. Flap down landings are just silly. The airspeed drops to around 5 mph at touchdown.

But takeoff and landing ease are not the true determinants for a good basic trainer. The Telemaster Electro will fly about 18 minutes, maybe more depending on throttle settings, on a single charge in its 3-cell, 4400 mAh Poly Quest Lithium-Polymer battery. That equals, or exceeds, the training time provided by most glow-powered basic trainers.

In flight, the Telemaster does not gain airspeed when the new pilot lets the nose drop in a turn. The big, 13-inch diameter propeller acts as an airbrake and stabilizers the airplane’s airspeed. The large wings, including the stabilizer here, provide so much lift that very little up elevator is required to hold altitude in a turn banked up to about 45 degrees. So the airplane doesn’t drop its nose much even if the pilot doesn’t help his aircraft fly the turn.

 

 

Photo 70           Photo 71

Because the airplane flies so slowly, yet remains responsive, the new pilot has plenty of time to decide the correct aileron input direction as the airplane flies toward the pilot. But coming or going, the Telemaster Electro is the most honest and easiest to fly sport/trainer aircraft we have tested so far.

Photo 72

Using the flaps opens up some interesting flight possibilities. With full flaps deployed, the Telemaster Electro can maintain about a 40-degree dive without gaining meaningful airspeed (photo 72). If the pilot wants to fly from a small field, just drop the flaps, point the nose down from a hundred feet up and land straight ahead. The entire approach and full-stop landing won’t require more than about 150 ft. even in calm wind conditions.

Summary

 

Photo 73

There are many reasons why the Telemaster Aircraft Series has remained popular for the last 30 years. The airplane is a delight to fly, performs well, is a great basic trainer, and a very good sport flying aircraft while putting few demands on the pilot’s skill. The flaps make it versatile and the light ARF construction makes in convenient. The Telemaster Electro moves another step ahead as it takes us into the next generation of model flight; practical electric power.

At $150 for the complete ARF kit, it also a good value. The airplane does require the Axi 28/26/12 motor, Jeti 40-amp speed control (or equiv.) and a 4400 mAh battery, radio system and some accessories. For complete information on this new version of a popular legend, go to: http://www.masportaviator.com/redirect.asp?website=ArticleLink_HobbyLobby_Telemaster

 

AIRCRAFT SPECIFICATIONS Manufacturer: Hobby Lobby             Length:           53.5 in.                        Cost: $150.00                                     Wingspan:       73.25 in. Radio: Hitec 6-Channel Rec.               Wing Area:     848 sq. in. Servos: 6 x Hitec HS-322HD             Wing Loading: 15.95 oz./sq. ft. Engine: AXI 28/26/12                         Weight:           5.87 lb. Airfoil: Flat Bottom

Special Features Giant wing with gobs of lift, Operational flaps, Quick Assembly.

Notable Positives Excellent flight characteristics Extremely fast and easy assembly Very good looks Very light flying weight Excel. basic trainer performance Extremely versatile with flaps Very low pilot workload. Notable Negatives Built slightly tail heavy

Electric Power Specifications Prop: APC 13 x 8 E       Max RPM: 6,700 Max Watts: 337W          Power Loading: 3.59 W/oz. Max Voltage: 11.0V       Max Current: 31 Amps Motor Run Time: 16-19 minutes

Improving the Electric Telemaster’s Appearance

As any reader of the Telemaster Electro ARF article above can tell, I was impressed with this airplane. To be honest, I have always enjoyed flying the Telemaster series. I think so highly of the Telemaster design that I had to work very hard to design an airplane that would out-fly it. That was a difficult task and it succeeded only by using foam core materials, a pumped engine and a 2-liter fuel tank. These were all tricks that the production Telemaster could not use. Even then, the flight improvements were barely noticeable except for the 2-hour flight times.

The Telemaster Electro is a worthy member of its Family. Almost everything about this electric-powered airplane is just right. To me, the one aspect that could use some improvement is its appearance. The transparent color scheme is very good but lacks those few finishing touches that would make it all come together. I thought there might be a few things that I could do to improve the aircraft’s looks without ruining the ARF concept or getting too far away from the airplane’s simple nature.

Step One

Photo 1

The first change was about the easiest. After visiting my local hobby shop, the Telemaster Electro now had a new white spinner. Somehow the airplane looked unfinished without one. Since the primary trim color was white, the white spinner fit right in. The 2-inch diameter spinner is made by Du-Bro® and costs about $7.00. I chose a smaller sized spinner to keep the rotating weight to a minimum. There are spinners made just for electric power but I didn’t see any at the shop. Besides, they cost more and the Du-Bro spinner was light and did not noticeably affect the motor’s acceleration rate.

The propeller slots in the spinner’s nose cone must be enlarged to fit the Telemaster’s 13-inch diameter propeller. If you have a high-speed rotary tool, use it with a fine sanding disk. If not, enlarge the slots using a file. Do not try to use a hobby razor knife. The plastic material is thick, strong and requires a lot of cutting force. While the nose cone can be cut using a very sharp hobby razor knife, doing so is a sure trip to the hospital emergency room. Trust me, I know this.

After the slots are enlarged, use a propeller balancer to rebalance the nose cone and completed spinner. All of the current propeller balancers have instructions on how to balance spinners. Always balance both the propeller and spinner on any airplane.

Step Two

Photo 2

The next appearance upgrade is optional and also the most difficult of all the appearance modifications. It is not mandatory but it does improve the airplane’s looks. Eliminating those pesky, messy rubber bands is, to me, a must do. Yes, a rubber band mounted wing does separate from the fuselage more easily during a crash. But the constantly varying roll trim changes resulting from never having the wing in the exact same place flying session to flying session is enough to eliminate any advantage.

Besides, rubber bands get messy, can damage the wing’s trailing edges and must always be replaced. Rather then deal with the stretchy hassle, this Telemaster was converted to a nylon bolt mounting system. Photo 2 shows the completed fuselage transformation.

  

Photo 3              Photo 4

How to make this simple conversion is outside the scope of this update. However, complete instructions on converting a high-wing airplane to nylon bolts are detailed in the Sport Aviator article, “Not Your Stock HobbiStar Part One”. Photos 3 and 4 provide a close-up view of the completed maple blocks now residing in the fuselage. As described in the article, the wing uses 1/4-inch hollow fiberglass arrow shafts as bolt guides. The Telemaster Electro’s plywood trailing edge brace meant to protect this thin area of the wing from the rubber bands also works well protecting the rear of the wing from the bolts.

However, since the Telemaster’s wing had already been assembled, the front bolt wing hole had to be carefully drilled through the joined center ribs. Fortunately, the Telemaster Electro has thick center ribs making this task easier. Start the hole using a 1/8-inch drill bit, preferably mounted in a high-speed rotary tool. The small bit makes guiding the hole easier. Then graduate in small increments to larger drill bits to enlarge the hole.

Make the wing hole first, before mounting the front plate in the fuselage. Insert the fiberglass shaft and complete the rear wing mounting system. Using the existing rubber band system, center the wing. Insert the two rear bolts and make sure the wing is centered. Only then, determine where the front maple block is to be mounted and install it. Finally, remove the two rubber band dowels and cover the fuselage holes with some material taken from the center underside of the wing.

Step Three

  

Photo 5         Photo 6

The white trim on the transparent red covering is attractive. The white area hides the wing’s sheeting while the transparent red shows its structure. Few things in model aviation look better than the bright summer sun shining through a transparent wing.

To make this effect even more striking, try adding a black holding line (the airplane’s tertiary trim color is black) between the red and white colors. Photo 5 shows the 3/16-inch wing holding line. Photo 6 shows the 5/32-inch holding line on the horizontal stabilizer. While not clearly evident in the photos, the holding lines make for a striking appearance improvement.

The original plan was to put white stripes on the wing underside. But the stripes would appear dark when viewed through the upper wing’s transparent covering. Continuing the white stripe onto the top wing surface did not fit well with the white leading edges. So that plan was dropped.

The vertical fin could also use some white trim. Putting your AMA number here in 1-inch white numbers would be good as would be some form of stylized design. For me, I just put the airplane’s number on the fin using 2-inch numbers since only three digits are involved. And for those who have asked before, my airplanes are sequentially numbered making this Telemaster Electro my 164th airplane.

Step Four

Photo 7

The final appearance upgrade is the addition of light wheel pants. A few companies still sell wheel pants. Fiberglass Specialties and Tower Hobbies have a good selection of wheel pants. The ones used on this Telemaster are from an old Ultimate Bipe ARF model. They are 7.25 inches long and 1 inch wide. The stock wheels easily fit inside. The size and shape seem right for this airplane. They were painted white for this application. The total all-up weight is 1.1 ounces. As photo 7 shows, the extra weight had no effect on the airplane’s performance.

The Final Result

  

Photo 8           Photo 9

The total extra building time was about four hours. Installing the nylon wing bolt system required 2.5 hours. The rest took only 90 minutes to finish. I liked the original’s appearance (photo but the updated version (photo 9) seems more “finished”.

Photo 10

For me, I especially like the “rubber band-less” appearance of the updated version. In addition to looking better, the airplane now keeps it roll trim from one flight session to the next. 

  

Photo 11         Photo 12

Once in the air, the “modified” Telemaster Electro looks even better. The white wheel pants and spinner really add a striking effect.

Photo 13

The extra white brightens the airplane’s appearance and makes up for not having the white wing stripes. Visibility is also better because of the additional bright areas. The extra white color sets off the transparent wings when viewed from below.

  

Photo 14          Photo 15

That extra color really shows itself on approaches and landings.

Even if you decide to retain the rubber band wing, try making the other modifications to the Telemaster Electro. You will be glad you did and proud of the results.

Q

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