Telemaster with Micropilot MP2028G Autopilot... Also Project Log

[tnavressdog]

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[dalbert02]

Do you have any more info on what exactly you did with it? A mission synopsis would be wonderful. Thank you,
-dave

[tnavressdog]

A little bit about the aircraft.

The airframe used was a 73" wingspan Telemaster Electro from Hobby-Lobby. It was modified by increasing the size of the rudder for more control authority and the elevator and rudder servos were located to the rear to open up extra room in the main compartment of the aircraft.

The Telemaster was chosen for its stable flying characteristics and ability to carry a heavy load. Even when all electronics were added to the aircraft, the way the airplane flew didn't change much. I modified the vertical and horizontal stabilizer to be removable for transportability. The wing, originally intended to be one piece, was also modified to be two-piece and could be attached with nylon screws. To make this modification, I wrapped the inner spar area of the wings with carbon fiber to make sure they would not explode at high flight loads. Also, the plywood spar itself was strengthened with some carbon fiber. Lastly, plywood was used to make the connection between wing and aircraft body instead of the rubber bands that came with the kit.

Power came from a Hexatronic 42-50 brushless motor ($33). Flights were with a Phoenix 35 speed control, 8-cell GP-3300 NIMH batteries, and 14x8.5 APC prop. Full throttle was less than 300 watts but this was still sufficient even when the aircraft was fully loaded. Cruise power was around 150 watts but oftentimes I was able to turn off the motor since the aircraft could actually thermal at times. I installed a Phoenix 45 in later flights since I liked to fly the airplane more rigorously for fun with 4-cell A123 batteries but all autonomous flights were done with the NIMH setup.

Servos were 6 HS-81MG and HS-81 servos for ailerons, flaps, elevator, and rudder. I mixed in crow and flaps that functioned as ailerons also to allow for short field takeoff and landing. An UBEC was used to power the receiver, servos, and electric switch used to switch between autopilot and manual control.

[tnavressdog]

Believe it or not the picture of the Telemaster just leaving the ground was powered with an Endoplasma brushed motor. This was on a flight just prior to mounting the electronics and new brushless motor.

The other three pictures were taken after electronics and new power system had been installed and show some of the aircraft modifications done.

Documentation of electronics system to come...

[tnavressdog]

The brain of the UAV was the Micropilot MP2028G autopilot. This was connected to a radio modem to allow real-time communications with the ground station. Although the Micropilot has a built in switch between autopilot and manual control, I decided to add an extra electronic switch to fill this function. I wanted the extra insurance that I would always be able to take control of the aircraft in case something went wrong.

From the pictures, you can see the Micropilot mounted on top of a plywood mount and the radio modem attached to the wall of the cabin. I used neodymium magnets to secure the plywood mount so I could remove the electronics easily if I so desired. On the bottom of the plywood mount (hidden), are the servo control board and electronic switch. Another one of the pictures show this electronic switch called the Rx_Mux. Input 1 to the electronic switch came from a Futaba PCM R148DP receiver. Input 2 came from the MP2028G and the output went to the servos. The BEC to power the servos, switch, receiver, and servo board was also located below the plywood. The main flight battery (GP3300s) powered the BEC.

Up front you can see the two cell lithium ion battery I used to power the Micropilot, GPS, and radio modem. I pulled the cells from a discarded laptop battery and each lithium-ion pack provides power for approximately 2-3 hours.

The 900 Mhz spread spectrum radio modem has a 60 mile range but I did not fully utilize its power for my UAV flights since all flights done were within visual range. Also something of note is that there is a board between the MP2028G and the radio modem. This is a RS232 to TTL converter.

I mounted the GPS antenna just behind the cabin on a copper plate. This helped the GPS acquire satellites faster by allowing better reception.

[dalbert02]

Wow, very cool!
-dave

[Suresh]

The brain of the UAV was the Micropilot MP2028G autopilot. This was connected to a radio modem to allow real-time communications with the ground station. Although the Micropilot has a built in switch between autopilot and manual control, I decided to add an extra electronic switch to fill this function. I wanted the extra insurance that I would always be able to take control of the aircraft in case something went wrong.

From the pictures, you can see the Micropilot mounted on top of a plywood mount and the radio modem attached to the wall of the cabin. I used neodymium magnets to secure the plywood mount so I could remove the electronics easily if I so desired. On the bottom of the plywood mount (hidden), are the servo control board and electronic switch. Another one of the pictures show this electronic switch called the Rx_Mux. Input 1 to the electronic switch came from a Futaba PCM R148DP receiver. Input 2 came from the MP2028G and the output went to the servos. The BEC to power the servos, switch, receiver, and servo board was also located below the plywood. The main flight battery (GP3300s) powered the BEC.

Up front you can see the two cell lithium ion battery I used to power the Micropilot, GPS, and radio modem. I pulled the cells from a discarded laptop battery and each lithium-ion pack provides power for approximately 2-3 hours.

The 900 Mhz spread spectrum radio modem has a 60 mile range but I did not fully utilize its power for my UAV flights since all flights done were within visual range. Also something of note is that there is a board between the MP2028G and the radio modem. This is a RS232 to TTL converter.

I mounted the GPS antenna just behind the cabin on a copper plate. This helped the GPS acquire satellites faster by allowing better reception.


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