Download Spektrum DX6 Surgery Butchery

Spektrum DX6 Surgery Butchery
Ever since I started Kite Aerial Photography back in 2002, I’ve used radio control (of the type
used to control model planes) to pan, tilt and click the shutter. Back in 2008 I bought a
Spektrum DX6 system to replace the 35MHz set I was using, intending to ‘chop’ it as Cris
Benton did his1 but my nerve failed at the work involved and I bought and attacked a
Turborix 2.4GHz transmitter instead2. The result, while not shapely or beautiful, was
reasonably adapted to one-hand use.
Cris Benton’s Chopped Spektrum
My Chopped Turborix
During a lengthy holiday in Italy this summer, the battery shifted inside my transmitter and
broke a key connector. I made a temporary repair, but on returning to the UK I made a
simple 6-channel 433MHz replacement instead3, but though cheap to construct, it’s not ideal
in use. Using buttons to tilt ‘up’ and ‘down’ means you don’t have much idea of where the
camera is pointing unless it’s close enough to see or you have a video downlink.
So, with KAPiFrance coming up in October, I decided to attack my aged Spektrum.
Design Criteria
Looking at what Cris had done, I decided:

to copy his ‘case’ design to keep the ergonomic advantages

to position the shutter switch, as Cris had, at the top left of the ‘box’

to use a rocker switch for panning, combined with continuous-rotation servo, just as I
had for my customized Turborix (Cris used a wheel since he uses unmodified servos
for panning (combined with 4:1 gearing). I wanted this to be on the left-hand side of
the box so I could operate it with my thumb

to use a wheel not a slider for tilt (I’d found this worked well on my modified Turborix)
and position this at the top right of the ‘box’

to retain the trim switches for the pan channel (to stop creep) as well as for the tilt
channel (to adjust the horizontal and vertical positions). These trim switches needed
to be positioned lower down on each side

to retain the other switch on the TX for possible future use (e.g. HoVer) and put this
(as Cris had) on the front panel
see http://arch.ced.berkeley.edu/kap/wind/?p=35
2
see http://www.zenoshrdlu.com/kapstuff/TurborixKAPController.pdf
3
See http://www.zenoshrdlu.com/433KAP Dave Mitchell
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1 Spektrum DX6 Surgery Butchery
First Steps
Having disassembled the TX, like Cris it was with some trepidation that I ran the case
through the band saw, trying to cut along the same lines that Cris had. Luckily there was little
splintering of the plastic.
Then I spent quite some time looking at the photos Cris had
published to see how he had made his case and fitted it to the
cut-down plastic front and back. While Cris’s photos were very
useful, they didn’t quite cover all the angles, but eventually I
figured out what was needed.
First I made replacement side and front panels, using 4mm ply for the panels and some
rectangular birch for the small battens used to screw the panels together.
I then glued further wood panels cut from birch sheets to build up the outside of the upper
part of the sides and sanded them into roughly the shape that Cris had made. Unlike Cris, I
also made a wooden cover for the battery compartment at the rear – when screwed into
place this makes the whole box more rigid.
Time to paint everything. I used a tin of red spray paint which did the job well, but I failed to
properly cover up the front window over the LCD display – some paint leaked in at the sides.
I used the same paint on the wood panels.
Dave Mitchell
2 Spektrum DX6 Surgery Butchery
Circuits and Controls
For the four channels needed I decided, like Cris, to use the two switches and two of the four
joystick channels, one on each side. The Spektrum joysticks have integrated electronic
(rather than mechanical) trims – each trim lever presses on one of two small button switches
as it is moved from side to side.
Each joystick channel has a small circuit board to which the potentiometer and trim buttons
are soldered. The four wires are 5v, joystick output voltage, trim output (either 0v, 5v or
floating) and 0v (ground).
Since I needed to retain the trims, I had to figure out a way of ‘surfacing’ them on the outside
of the case. I decided to desolder the potentiometers:


the tilt one, controlled by an external wheel, needed to be located some distance from its
trim buttons
the pan one needed to be replaced by a rocker switch and resistor network
I also cut off the wire connector from the circuit boards so the result could be fixed inside the
case with the trim buttons protruding through to the outside.
Dave Mitchell
3 Spektrum DX6 Surgery Butchery
Inside view of Circuit board
Outside view of trim buttons
The pan circuit replacing the potentiometer looks like this:
The rocker switch is actually composed of two
push button switches – the rocker switch I used on
my Turborix conversion was too large to fit.
Having decided on the layout of the controls, I cut the necessary holes in the case.
Shutter
Spare switch
Pan
Tilt
On/Off switch
Pan Trims
Tilt Trims
Charging Socket
Like Cris I wanted a strap at the back to make it easier to grip the transmitter. I screwed two
aluminium strips to the back and used some upholstery webbing and Velcro (from an IKEA
cable tidy).
Dave Mitchell
4 Spektrum DX6 Surgery Butchery
Wiring everything up was arduous (my soldering technique is poor) but straightforward. The
result is certainly not as need and tidy as Cris’s, but it’s good enough for me!
Note that the Spektrum antenna has been drastically shortened – the active portion at the
end is just 3cm long.
Dave Mitchell
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