Obsolete – The Easystar is no longer in use.
This is my Easystar FPV (First Person Video) model aircraft project.
The Multiplex Easystar is the favourit choice to build an FPV aircraft. Cheap, easy to build, easy to fly and because of the pusher engine there is no propeller in front. It´s fuselage and wings made from Elapor foam is easy to handle, nearly impossible to destroy and a good base to modify the aircraft for FPV needs.
The following documentation shows some steps during my construction progress and may you get an idea about the modifcations I did on my Easystar.
First a list of components I used for the aircraft:
- Multiplex EasyStar kit, www.multiplex-rc.de
- Schulze alpha-8.35s 35MHz receiver with RSSI output, www.schulze-elektronik-gmbh.de
- Simprop Magic 30-H brushless controller, www.simprop.de
- AHM 23-10 ES brushless motor, www.ahm-rc.de
- Motor frame for AHM 23-10 ES, www.ahm-rc.de
- Push-Prop holder for Graupner Cam folding props, www.ahm-rc.de
- Graupner Cam folding prop 8″-4.5″, better non-folding APC 7″x5″ E
- Hitec HS-81 servos for elevador and rudder, www.hitecrc.de
- Hitec HS-55 servos for ailerons, www.hitecrc.de
- Kokam 3S1P 3200mAh LiPo batteries from my Mikrokopter
- Take-off weight of the aircraft with FPV equipment actual 1060g
STEP 1 – Making space for the hugh LiPo battery, the motor and brushless controller
In the lower part of the inner fuselage there is enough space now
for the battery. The correct position of the battery will be determinated later to adjust the COG. Since I want to add the FPV equipment where the canopy should be, the battery can be moved also behind the defined COG for better adjustment possibility.
The motor frame is already glued in one half of the fuselage and you can see the space where the BLC will be placed – directly in front of the motor. The advantage are the short motor wiring (to keep EMI as low as possible) and the BLC will be situated in the cooling air flow which goes through the motor nacelle.
I also enlarged the canopy opening by 1cm cutting the front part a bit. For the reason to get the battery out of the fuselage more easy.
STEP 2 – Brushless controller fixed and place for receiver found
A bit hot glue keeps the BLC in place and fixes the cable routing.
There will be some space left and right of the BLC to be able to reach the screws which fix the motor to the frame even when both fuselage frames are glued together.
The battery and recever are temporary put on there foreseen places. The battery will move fore or aft to adjust the right COG.
STEP 4 – Tail reinforcement
The tail of the EasyStar is reinforced with a 10mm carbon tube. Also the space for the 8″x4.5″ folding prob is visible.
STEP 5 – Ailerons
A very popular modification of the EasyStar are ailerons. The main reason for this modification is the small rudder, so people either making a bigger rudder or adding ailerons. Ailerons making more sense since you add another control option to the aircraft. I will use them not with an Y cable but each servo connected to a separate channel which give the full mixer authority of the transmitter.
Each aileron servo is placed vertically in the airfoil with the control arm on the top side of the wing. There are two reasons for this, first to keep the air flow on the lower side of the wing as laminar as possible, and second to protect the servo in case of landing in high grass. (Based on experience from people in the EasyStar forum)
STEP 5.1 – Make the wings more rigid – recommended!
The standard wing spare which comes in the kit is nice, but not enough. During a hard landing one of the wing half broke right where the spare ended.
On a new wing I glued 55cm long, 8mm diameter, carbon tubes in each wing half. The original slot has to be extended for this.
A 6mm carbon tube, length like the original wing spare, is glued half in the 8mm carbon tube of one wing. The remaining half of the 6mm carbon tube will slide into the 8mm tube in the other wing.
Result is an incredible rigid, unbreakable wing.
STEP 6 – Power to the fuselage – the motor
The two halfs of the fuselage are now glued together and the AHM 23-10 ES BL motor is installed.Since the BLC is directly behind the motor the cables are very short, but long enough to pull the motor out for soldering the wires. The wires are rolled beside the BLC when the motor is fixed to the frame.
The space cutted for the prop is now covered by some layers glass to cover all holes from cutting, stabilize the section a bit more and for good airflow. There is enough space for the actual installed 8″x4.5″(20-11) propeller. Performance with the CAM prop is ok so far and drives the EasyStar very good.
Now I use a APC 7×5 prop with the AHM 23-10 and this is a real performance boost. Also the prop is less noisy.
Two screws, secured with Loctide, fixing the motor to the frame. They are reachable through the NACA inlet in front of the motor nacelle, left and right of the BL controller. A bit tricky to install but not impossible – hopefully no need to remove them to often. 🙂
In the middle of the air inlet you can see the BLC sitting directly in the airflow, so very good conditions for cooling.
STEP 7 – Ready to fly
Finally my Easy is ready to fly.
Fuselage and wings are ready, servos and receiver connected. Before maiden flight I need to setup the right COG which will be tricky I think. Since I modified the motor and propeller the performance will be much higher than the basic power set.
With the motor just turning in idle the nose is already pushed down. So for full power the COG must move far back than the recommended setting of the instruction.
The Easy is sitting on a simple wooden scale for estimating the COG.
By the way, take-off weight measured in this configuration is 831g.
STEP 8 -Painted
Finally the EasyStar is really finished. I put some paint on it, light grey and orange, and black on the nose to reduce shutter effects for the FPV camera.
FPV Step 1 – The carrier
The fix part of my FPV camera carrier is finished.
Made from 2mm and 1mm plywood the carrier hold the pan part of the camera, a place for the video transmitter and also a GPS receiver. A Wi.232 will be added later for telemetry down-link to a ground station.
The FPV carrier is already made and tested. Unfortunately the pan servo, a Hitec HS-55, is not able to make a 180° turn. I already tried to modify it put the potentiometer inside the servo is the limiting factor here.
The antenna is a self-made coaxial type, tuned with a Vector Network Analyzer for best VSWR results at the desired video channel.
I´m just thinking to add a clear plastic ball around the camera for protection and better aerodynamics. Now it´s like a brick in the wind.
My EasyStar ready for operation:
Take-off weight of the full operational Easystar is now 1060g.
FPV carrier with Pan&Tilt, Video transmitter and Wi.232 module. The GPS is integrated below the square field in the nose. An air-intake is needed to keep the Remzibi OSD cooled.
The Remzibi OSD is fixed below the FPV carrier. The FPV equipment is powered from the main battery through an EMI filter made of a 100uH/2A coil, two 100nF capacitors and a 100uF capacitor. GPS is powered through the OSD. An analog input of the OSD is used to show the RSSI level from the Schulze receiver.