SkyMixer50 Quadrotor Do-It-Yourself version

This article describe plans, instructions, and material you need to build your own basic 50cm (19.7") wingspan quadrotor frame.

SkyMixer50 DIY assembled

 


Table of contents



Features

  • 500mm (19.7") wingspan
  • 370grams alll up weight (depending on used materials)
  • New brushless motor controllers
  • New control board (for now, prototype will flight with microSMX-Pilot v1.00 control Board)
  • Possibility to adapt other popular control board (Paparazzi Booz, etc.)
  • Optimized price/weight/solidity ratio


Skills

Under construction...


 


Bill of material

Under construction...

SkyMixer50 DIY parts

Part Qty Use Comment Distributor Product link

 


 


Tools

Essential Tools

Under construction...

Tools that make things easier

Under construction...

 



Frame plates cutting out

skymixer50diy_v100_all_parts_a4_200

SkyMixer50_DIY_body_parts_200



Preparation


Square tubes cutting and marking

Parts needed for this stage:

  • 6mm side x 4.2mm internal diameter hollow carbon square tube

6mm side x 4.2mm ID hollow carbon square tube

  • Carbon tubes can be replaced by same external dimensions (6mm side) aluminiun square tube
  • Aluminium is cheaper, easier to find but heavier ...

6mm side x 1mm thickness aluminium square tube

  • Cut two pieces 270mm length

270mm frame tubes

  • On the same side mark the two tubes at 102mm from each end.
  • Use a sharp point tool

Two marks at 102mm from the end 

Tubes marks


Central middle plate

A gash must be made on the Central Middle Plate in order to get the antenna wire through the plate without dissoldering the antenna connector

Gash for antenna wire


Motor holder modification

Motor holders (x4) must be drilled again to be able to use M3 diameter screws and install it upside down.

  • Remove set screws
  • Drill again the motor holders at the specified diameter

Drill again motor holder

  • put the set srews back in

Motor wires replacement (optional but recommended)

This stage is optional, but choosen motors comes with stupidly stiff wire difficult to install correctly on Motor Plate.

So, it is recommended to replace it with flexible silicon wire.

Parts needed for this stage (for one motor):

  • (3x) ~60mm lenght 24AWG silicon cable
  • Ø3mm x 12mm heat shrink tube
  • Ø6mm x 20mm heat shrink tube
  • Remove first(?) heatshrink cover layer with the modelling knife.

First wire covering layer out

  • Remove second(!) heatshrink cover layer

Second wire covering layer out

  • Remove third(!!) heatshrink cover layer (hopefully it's the last one!)
  • Note that the twin wire to improve strength. It explains the stiffness...

Last heatshrink cover layer out

  • Cut the 3 remaining wires respectively at 12, 15 and 18mm from the motor base

Cut the wire at different length

  • Remove 3mm length varnish coat from the end of the wires

Ready to solder new soft wires

  • Solder new wires
  • Slip heatshrink tubes onto wires

New wires

  • Heat up to shrink each individual wires
  • Shrink the complete wire set with the Ø6mm tube

Wire set almost done

 


Battery power supply cables

Parts needed for this stage:

  • 25mm lenght 16AWG red and black silicon cable
  • (2x) male 2mm plug (PK2)
  • (2x) female 2mm plug (PK2)
  • (1x) Ø4mm x 25mm black heat shrink tube
  • (1x) Ø4mm x 25mm red heat shrink tube
  • (1x) Ø4mm x 15mm black heat shrink tube
  • (1x) Ø4mm x 15mm red heat shrink tube

Parts needed for central power supply cable

  • Solder red cable on male plug and black cable on female plug

Power plugs soldering

  • Install heat shrink tubes

Power cables heat shrink tubes installation

  • Repeat operation with battery cables, inverting genders (female red, male black)

Parts for battery wiring

Battery wiring


Power Board wiring

The Power Board supply energy from the battery to the four brushless controllers and the control board of the quadrotor:

Parts needed for this stage:

  • Power Board ring
  • Battery power supply cables for battery connection (red wire male plug + black wire female plug)
  • (x1) 26AWG red cable ~30mm for control board supply +
  • (x1) 26AWG black cable ~30mm for control board supply -
  • (x4) 20AWG red cable 90mm for brushless controllers supply +
  • (x4) 20AWG black cable 90mm for brushless controllers supply -

Power Baord and supply cables

  • Solder all the red cables on the same face as shown on the picture
  • cable insulator must touch (or overlap) the ring edge to avoid shorts

Solder all plus wires on this power board face

  • Solder all the black cables on the other face as shown on the picture
  • No short allowed ! (Check ten times!)

Solder all minus wires on this power board face


RC receiver modification

If the used control board needs RC PPM signal, hack the receiver as recommended here.

Parts needed for this stage:

  • (1x) RC receiver PPM hacked + crystal
  • (1x) Ø2mm female banana socket + matching nut
  • (1x) Ø3mm x 12mm heat shrink tube
  • Cut the antenna wire at ~90mm from the receiver

CIMG8309

  • Slip heat shrink tube onto antenna wire
  • Solder the banana socket

CIMG8313

  • Heat up

CIMG8316

 


Antenna building

For this stage you need:

  • Ø0.8mm x 300mm music wire
  • (1x) male 2mm banana plug (PK2)
  • (1x) Ø4mm x ~20mm black heat shrink tube
  • (1x) Ø4mm x 15mm colored heat shrink tube (yellow here)

Antenna building parts

  • Sand one end of the music wire to make the soldering easier

Sand one end

  • Solder music wire into plug, keep it aligned

Solder music wire and male plug

  • Add heat shrink tube for look and easier handling

Plug packaging

  • Bend back the other end of the music wire (or someone gonna loose an eye...)

Bend back other end

  • Add colored heat shrink tube (kind of visual warning)

Add visual warning

  • Ready for fishing receiving

Antenna ready



Assembly


Central mount assembly

Finished central mount overview

Parts needed for this stage:

  • Central top plate
  • Central middle plate
  • Central bottom plate
  • (6x) cheese head M3 x 12mm nylon screws
  • (6x) flat head M3 x 12mm nylon screws
  • (4x) male-female threaded M3 x 10mm plastic standoffs

Parts needed for central mount assembly

  • Pre-assemble central middle plate and central top plate using all the cheese head srews.
    (Tighten loosely and pay attention to the picture to find the right way to assemble)

Central middle plate and central top plate pre-assembly

  • Pre-assemble central bottom plate using all the flat head screws.
    (Tighten loosely and pay attention to the picture to find the right way to assemble)

Central bottom plate pre-assembly

  • Screw the four standoffs onto the middle plate. Do it manually to not overtighten.

Electronic's standoffs installation


Frame assembly

Parts needed for this stage:

Parts needed for frame assembly

  • Slip first square tube into central mount and  tighten loosely

First square tube installation

  • Align tube mark with central middle plate edge and screw firmly (do not not overtighten)

First square tube alignment

  • Repeat operation with second tube

Second square tube installation and alignment 

Finished frame assembly overview


Propelling devices assembly

Instructions to assemble x4 propelling devices

Finished SkyMixer50 propelling device overview

Parts needed for this stage (for each propelling device):

  • Motor (with replaced wires)
  • Motor plate
  • Motor flange
  • Brushless motor
  • Modified motor holder
  • Propeller shaft adapter
  • I2C brushless motor controller
  • I2C cable and connector assembly
  • Ø33mm x 25mm transparent heat shrink tube
  • (8x) cheese head M3 x 12 nylon screws

Parts needed for propelling device assembly

  • Reduce motor wires length if needed (60mm)

Parts needed for propelling device assembly

  • Solder motor wires on motor controller
    (further wire swapping could be necessary to meet rotation direction needs)

Motor wires soldering

  • Fasten motor holder on Motor Plate with 4x cheese head M3 x 12 nylon screws

Motor holder installation

  • Slip Motor Plate and motor controller into heatshri