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After building four Telemaster 40 kits over a span of twenty-six years, and using the last two specifically as aero tow tugs, we were very excited to have the opportunity to build the new Hobby Express Deluxe Telemaster 40 kit shortly after its release.
Hobby Express has the kit building instructions, complete with step-by-step color pictures, posted on their website (www.hobbyexpress.com). Just click on the “Support†tab under the Deluxe Telemaster 40 kit section and then click on the words “Deluxe Telemaster 40 Manual†to open and see the manual. The Deluxe Telemaster 40 kit is a quantum leap forward in kit design featuring full laser cut parts. Even the hinge slots are laser cut! Unlike the older kits, the Deluxe Telemaster 40 kit parts are designed to interlock in a way that makes it very easy to build a straight and true structure quickly. We were able to frame up the complete airframe in 22 hours and this was done using Titebond II (aliphatic resin) glue for most of the construction instead of instant (cyanoacrylate) glue!
The original Telemaster 40 kit had ailerons and offered flaps as an option. The Deluxe Telemaster 40 kit comes standard with ailerons, flaps, and a four-servo wing so each surface can be independently controlled. A basic 6-channel radio system can be used by coupling the two aileron servos with a Y-harness and the two flap servos with a Y-harness. For those with a more advanced radio system offering computerized mixing capability, the Deluxe Telemaster 40 can become a test bed for all sorts of wing control mixing. We like the “crow†function with flaps down and ailerons up for rapid descents and short field landings. This is of particular value in an airplane used for aero towing sailplanes.
We were very pleased to discover that this new Deluxe Telemaster 40 kit is manufactured here in the U.S.A. We also have long been fans of the great DuBro products that are manufactured here in the U.S.A. as well. We used the following DuBro products to build our “Super†Deluxe Telemaster 40 Tow Plane:
A good tow plane needs a sturdy landing gear:
Elevator and rudder control rods.
Electric power (for models in this size class) has reached a point where it rivals the cost of glow power and exceeds the performance. In our experience, a 4-stroke glow engine is better than a 2-stroke engine for aero towing because of its low end torque. Electric motors have even better low end torque. As a rule of thumb, a tow plane typically needs a power system that is about half again larger than what would be used for a sport plane application. For our “Super†Deluxe Telemaster 40 tow plane, we opted for a .60-size electric power system from the Hobby Express eRC series (instead of the recommended .46-size motor):
The prop we selected is an APC 15x8 Thin Electric:
We made an opening under the motor mount so that the ESC could slide in under the battery platform. This also gives cooling airflow straight through the controller and provides a nice area that protects the ESC.
Our initial motor run was made with a 6-cell 5,000mAh 20c LiPo pack and produced 780 watts of power at 34 amps. We attached our fish scale and measured 8lbs. 7oz. of thrust. The AUW of our new Super Telemaster 40 Tow Plane is 8lbs. 3oz. so the thrust to weight ratio is greater than a 1:1! With this kind of power, we added plate washers to the left side of the motor mount to create right thrust. With a larger motor and with the extra drag of a sailplane on tow, the right thrust helps to keep the tow plane from yawing to the left and makes for better and straighter tows (and less need to hold right rudder).
Flight Report:
We settled on using two 3-cell 4500mAh LiPo packs connected in series so we could use our existing chargers that are limited to charging 1-4 cell packs. The packs are rated for a 30C continuous discharge rate. The battery tray area in the Telemaster extends from the firewall back to just in front of the servo tray, so the motor battery placement can be easily adjusted within this tray to achieve the desired CG location. Velcro tabs and straps were used to secure the batteries in place.
The CG location shown on the plans is 5-3/8†back from the leading edge of the wing. We have found that tow planes fly a little better if they are slightly nose heavy, remember you will be dragging that towline behind you once the sailplane releases. The Telemaster has a very wide CG range and we consider the point shown on the planes to be near the maximum aft location. Our plane was balanced at a point ½†aft of the main wing spar.
Our first flight was like the 100th flight on a proven and trusted model. Not even one click of trim was needed on any control. After flying the pattern and landing, a towline was attached and our new “Super†Deluxe Telemaster 40 tow plane was pressed into service.
After flying about eight launch and land circuits, we recharged the batteries to check the capacity and only 45% of the pack capacity had been used. Keep in mind that the radio operates from a separate battery pack. As additional flights were made and both the Multiplex Cularis and Easy Glider Pro sailplanes were towed multiple times we calculate that, if towing to a reasonable height, this setup will provide around sixteen circuits towing the Easy Glider Pro and about nine circuits towing the Cularis. If slightly larger capacity LiPo packs are used, these numbers could be even larger.
The eRC BL-60 motor was superb, providing plenty of power to tow a variety of sailplanes, from the 1.8M Multiplex Easy Glider Pro sailplane that weighs about 1.5lbs., to the larger 2.6M Multiplex Cularis sailplane that weighs about 3.0lbs., and other composite 2.6-3.0M sailplanes weighing up to 4.25lbs.
Hobby Express has the kit building instructions, complete with step-by-step color pictures, posted on their website (www.hobbyexpress.com). Just click on the “Support†tab under the Deluxe Telemaster 40 kit section and then click on the words “Deluxe Telemaster 40 Manual†to open and see the manual. The Deluxe Telemaster 40 kit is a quantum leap forward in kit design featuring full laser cut parts. Even the hinge slots are laser cut! Unlike the older kits, the Deluxe Telemaster 40 kit parts are designed to interlock in a way that makes it very easy to build a straight and true structure quickly. We were able to frame up the complete airframe in 22 hours and this was done using Titebond II (aliphatic resin) glue for most of the construction instead of instant (cyanoacrylate) glue!
The original Telemaster 40 kit had ailerons and offered flaps as an option. The Deluxe Telemaster 40 kit comes standard with ailerons, flaps, and a four-servo wing so each surface can be independently controlled. A basic 6-channel radio system can be used by coupling the two aileron servos with a Y-harness and the two flap servos with a Y-harness. For those with a more advanced radio system offering computerized mixing capability, the Deluxe Telemaster 40 can become a test bed for all sorts of wing control mixing. We like the “crow†function with flaps down and ailerons up for rapid descents and short field landings. This is of particular value in an airplane used for aero towing sailplanes.
We were very pleased to discover that this new Deluxe Telemaster 40 kit is manufactured here in the U.S.A. We also have long been fans of the great DuBro products that are manufactured here in the U.S.A. as well. We used the following DuBro products to build our “Super†Deluxe Telemaster 40 Tow Plane:
A good tow plane needs a sturdy landing gear:
- DUB789 - Super Strength Landing Gear
- DUB247 - Axle Shafts 5/32â€x1-1/4â€
- DUB140 - Dura-Collars 5/32â€
- DUB400RV - 4†Big Wheels
- DUB375 - Tail Wheel Bracket .40 Size
- DUB75TW - ¾â€Tail Wheel
Elevator and rudder control rods.
- DUB500 - Lazer Pushrod 36â€
- DUB121 - EZ Connectors
- DUB855 - E/Z Links 2-56
- DUB109 - 2-56 Spring Steel Kwik Link Clevis
- DUB855 - E/Z Links 2-56
Electric power (for models in this size class) has reached a point where it rivals the cost of glow power and exceeds the performance. In our experience, a 4-stroke glow engine is better than a 2-stroke engine for aero towing because of its low end torque. Electric motors have even better low end torque. As a rule of thumb, a tow plane typically needs a power system that is about half again larger than what would be used for a sport plane application. For our “Super†Deluxe Telemaster 40 tow plane, we opted for a .60-size electric power system from the Hobby Express eRC series (instead of the recommended .46-size motor):
- ERCBL60 - eRC BL60 motor
- ERCE085P - eRC 85A Brushless Programmable Opto ESC
The prop we selected is an APC 15x8 Thin Electric:
- LP15080E - APC 15x8 Thin Electric Prop
We made an opening under the motor mount so that the ESC could slide in under the battery platform. This also gives cooling airflow straight through the controller and provides a nice area that protects the ESC.
Our initial motor run was made with a 6-cell 5,000mAh 20c LiPo pack and produced 780 watts of power at 34 amps. We attached our fish scale and measured 8lbs. 7oz. of thrust. The AUW of our new Super Telemaster 40 Tow Plane is 8lbs. 3oz. so the thrust to weight ratio is greater than a 1:1! With this kind of power, we added plate washers to the left side of the motor mount to create right thrust. With a larger motor and with the extra drag of a sailplane on tow, the right thrust helps to keep the tow plane from yawing to the left and makes for better and straighter tows (and less need to hold right rudder).
Flight Report:
We settled on using two 3-cell 4500mAh LiPo packs connected in series so we could use our existing chargers that are limited to charging 1-4 cell packs. The packs are rated for a 30C continuous discharge rate. The battery tray area in the Telemaster extends from the firewall back to just in front of the servo tray, so the motor battery placement can be easily adjusted within this tray to achieve the desired CG location. Velcro tabs and straps were used to secure the batteries in place.
The CG location shown on the plans is 5-3/8†back from the leading edge of the wing. We have found that tow planes fly a little better if they are slightly nose heavy, remember you will be dragging that towline behind you once the sailplane releases. The Telemaster has a very wide CG range and we consider the point shown on the planes to be near the maximum aft location. Our plane was balanced at a point ½†aft of the main wing spar.
Our first flight was like the 100th flight on a proven and trusted model. Not even one click of trim was needed on any control. After flying the pattern and landing, a towline was attached and our new “Super†Deluxe Telemaster 40 tow plane was pressed into service.
After flying about eight launch and land circuits, we recharged the batteries to check the capacity and only 45% of the pack capacity had been used. Keep in mind that the radio operates from a separate battery pack. As additional flights were made and both the Multiplex Cularis and Easy Glider Pro sailplanes were towed multiple times we calculate that, if towing to a reasonable height, this setup will provide around sixteen circuits towing the Easy Glider Pro and about nine circuits towing the Cularis. If slightly larger capacity LiPo packs are used, these numbers could be even larger.
The eRC BL-60 motor was superb, providing plenty of power to tow a variety of sailplanes, from the 1.8M Multiplex Easy Glider Pro sailplane that weighs about 1.5lbs., to the larger 2.6M Multiplex Cularis sailplane that weighs about 3.0lbs., and other composite 2.6-3.0M sailplanes weighing up to 4.25lbs.
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