TRacer - FPV tricopter racer project: September 2015

This blog is to share my experience with a

DO IT YOURSELF

FPV RACER TRICOPTER

The project goals were:

….. Hold on … please let me first apologize for my terrible English but … is not my mother tongue

… so the goals……

· Class between 250 and 300

· Something different form the design available from the market quite all identical

· Foldable for easy transportation and … to take care of contact with trees , wall , earth …

· Fast and Quick flight characteristics

· Use of Mobius action cam

· Motor Class 18 with 5x3 propellers

· KK 2.15 cheap Controller for the prototype

1. DESIGN STAGE

After few night working on the CAD design and finding on the market available supports I reached

this prototype

Base infos :

Top and bottom plate – 1 mm Carbon sheet

Arms : 10 mm carbon tube

Yaw servo support: aluminium Tail servo support from Hely.

Tube holder : abs with titanium m3 bolts

2. YAW MECHANISM

I started working on the yaw mechanism because was the most critical DIY item.

To make the things easy I decided to build it using a blade holder from a 450 class hely … final

design will have instead a tailored mechanism.

Mechanism, even if will not be the final solution, is working quite well, it run without friction and is

quite robust. I choose as yaw servo an hitec hs 65 MG

3. PLATES

Then I moved to the top and bottom plate cutting them from a 1 mm carbon sheets.

No major issue on this step apart from the carbon dust … it went everywhere.

In order to correctly drill all the holes I temporally fixed the 2 sheet together and then start to drill.

4.ELECTRONIC's OPENING

Power distribution board and the kk controller opening cutted .

Bottom plate on the left for the PCB and top plate on the right with access hole for the kk.

PCB installed and arm fixed on tube holders; Blank test for the spacers to evaluate available space… nothing more to say for this step

5.ELECTRONIC INSTALLATION

Electronic components installation start…

12 amps (400 hz) esc welded to pcb and fixed to the plate with 3M holder

All esc mounted and connected to the pcb and an external bec installed to supply 5volts to rx and kk.

6. MOTOR INSTALLATION

DYS BE 1806-2300 motors installed.

All wiring routed inside the carbon tubes and cable directly welded on esc.

7. CONTROLLER

I then installed the KK 2.15 on rubber support to smooth vibrations.

8. FRAME MOUNTED

Finally top frame mounted. Still missing the cam mount in the model front.

9. CAMERA SUPPORT

Camera support was cutted directly from the top frame then reduced few millimeter in dimension to

allow free movements. Four holes have been drilled on it and on bottom frame for an installation

through 65 gramms vibration damping balls.

10.LANDING GEAR

Last missing items were the landing gear and battery support both of them forgotten at design

stage........

For the landing gear i decided to simply use a 4x25 screws fixed on spacetrs to support shock

absorbing foam skid collars.

While for the battery holder I used a simple Velcro strap fixed on the bottom.

11. SO FINALLY COMPLETED

I approached the scale and with a 3s 1500 mAmp battery installed total weight is 540 gramms .

TIME TO FLY………

After a flying session dedicated to the kk tuning ……well above all best expection…the drone is fast, quite quickly react to the command , it turn in centimeters.. still with the gyro of the kk fixed on “relaxed flight” values…next steps will be to increase gyro set , install the tx video and test the drone limits on FPV arrangement.

TRacer upgrade from Lesson learnt :

To revise yaw mechanism to smoooth operation
To add led in order to increase visibility
To enlarge Top and bottom plate few millimeter to allow a more easy components installation.
To increase Front in order to completely protect the Mobius (actually the lens is outside the frame.)
To test a different 32 bit controller (may be a Pixfalcon)
To reduce a little bit the arms to further increase the drone reactivity.