Ruggedised transmitter for remote camera control: part 1

KAP really puts kit through it. I had a transmitter smashed by a dog jumping on it, I have trodden on the thing whilst hauling line…and to cap it all on my last outing it smacked me in the face while I was getting me and my line over a gate…as the wind was dropping…doing 3 things at once is always going to find the weak spots in a system and sure enough, I jumped down..the radio whipped upwards and the neck-strap ensured the face plant..ouch!

I have kept spare (Spektrum Dx5e) radio and for a while I have thought repackaging it might be a good way of keeping the spare parts handy and perhaps get a ruggedised radio along the way. I have already looted a trimmer switch from it so it so it’s warranty is well voided and it’s ripe for plunder.

Process of elimination

IMG_1319

With the case off and 2 channel controllers removed this is the guts of the thing. The main board is 18cm long so this will determine the size of the case.   The channels are

  • Pan=Rudder=ch4
  • Tilt= Throttle=ch1
  • Shutter= Gear=ch5

The binding and rate switches are kept along with the trimmer control for the pan. The antenna will be replaced with a de-mountable SMA connector type

Removing the control potentiometers from the joysticks needs care. I wrecked one trying to lever it out of its plastic housing. They are fragile and don’t take well to levering. They are threaded, they unscrew.

IMG_1322

In theory I could stick a knob on the pot and that would do but I’d lose the self centreing and fine control of a stick and be left with lumpy knobs to break off so they will be replaced by a thumbstick of the game console type. With luck I’ll be able to pan tilt and shoot with one hand.

Replacement case. The box is the design constraint. The case needs to be tough, light and bash proof, waterproof would be nice but I don’t work in the rain.. It will need to be a secure enclosure for the brittle PCB, battery, connectors and be a rigid base for the joystick. Such things are made and they are come at a price. The main transmitter board is  18cm long so that’s the first constraint and after a day on the web I found the answer…

Tx rebuild 1 Tx rebuild 2

A 2 part sealed enclosure with engineered end caps, a battery compartment and slots for not one but 2 PCBs…and a carry strap: perfect. Made by Rolec in Germany these are not held in stock outside Germany. They are not cheap but should last a lifetime provided I can get the holes in the right places. Extruded aluminium section, neoprene rubber bead seals, screwed secured end caps: solid.

Power supply. The transmitter requires 6v but will take 7.4v from a 1500mAh Lipo. The ‘mobilCASE’ has a compartment designed for 4x AA cells. If I can get a high capacity battery in there I will, the Tx runs for hours at full output on the LiPo.

VRx. This is tricky, there is room for the board and if I can fit a 7.4v lipo in there all that needs to be solved is the screen. A big hole in the case could weaken it and the risk of scratching the screen suggests an internal mount is needed. Surface mounting may make the screen vulnerable to bump and scratch. Given the cost ( £60+ ) of the case the drilling of holes is a great worry. I’ll take a 2 step approach starting with a strap on screen and then moving on to a rigid mount if there is fixing space left on the top plate.

As I wait for the parts it dawns on me just how difficult this will be, machining the cut-outs for this is way beyond the capacity of my shed work shop…

B

About billboyheritagesurvey

Heritage worker
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