Build Log: Robotising a RC tank (first attempt)

[Fivetide]

I’ve always wanted to covert a Model Tank into a house guard or a garden rover, but never actually got around to starting one. There are certain things I want from it. Good range, lightweight and tracked, ultimately to have the ability to climb stairs. I see it as a little home sentinel, that can detect movement, sense smoke etc , that I can control from a web page or an android phone. It might sound silly but as a contractor I often spend a lot of time working away from home, although I have good neighbours who watch out for each other, they wouldn’t be able to sense a fire immediately and warm me, or want to tackle a burglar. That’s what I’m aiming for in the long term with a bespoke built robot, the tank is my R&D phase and if the Robot never appears then I have RC FPV BB tank I can play with in the garden.
Anyway I bought a Heng Long Walker Bulldog



*Not my tank but for reference.

There’s nothing fancy about it , no smoke or sound, and after a few hours playing around shooting various things (badly) it got a tad boring lol

So now it looks like this:



The idea is of what to create... is evolving as I go along. I first thought of using a wireless camera via my Wi-Fi network. This is fine but is very very limited. First of all the range would be poor unless I added repeaters or boosted the signal somehow. Anyway I decided to go for first person view equipment. Lots of range , lightweight for RC planes and lots of things on the forums to help me decide the correct equipment for my project.

The ultimate idea will be to use my CNC / Casting equipment to build a really robust rover , so this is my R&D phase plus I can have some fun.
So for the camera setup so far I have:
RX / TX


1.2GHz 800mW 8 Channel Digital Wireless AV transmitter & receiver


Camera


WDR700 OSD Color Camera 550 Lines SONY Super HAD II




Pan and Tilt


260 Degree Pan & Tilt Camera Mount




However as I said before this is evolving , mainly due to the fact I underestimated the space I have for the equipment.. next post will be control equipment.

[blackburn mark]

iv just been looking at what it would cost to use t2.5 belt for tracks :( ....a tad pricey once you get towards 1m lengths and 50mm width .... especialy if you use double sided
a shame because im guessing they might climb carpet at 45 degrees and would be nice n quiet for sneaking up on any cats taking a dump in your garden lol

[boldford]

. . . . would be nice n quiet for sneaking up on any cats taking a dump in your garden lol

And fire a BB right at their tea-towel holder.

[Fivetide]

iv just been looking at what it would cost to use t2.5 belt for tracks :( ....a tad pricey once you get towards 1m lengths and 50mm width .... especialy if you use double sided
a shame because im guessing they might climb carpet at 45 degrees and would be nice n quiet for sneaking up on any cats taking a dump in your garden lol

And fire a BB right at their tea-towel holder.

I'm saying nothing lol :) but your not far off the "Mark"


Hence why I’m thinking of swapping cameras to

1/3 SONY Colour 700TVL CCD Waterproof Camera, IR Distance: 50m

Give me more of a Stealth ability at night lol !

[Fivetide]

So part 2 Controller.


Well I’m not sure here, I have an Arduino Nano, which would server the purpose in all honesty, mainly because there’s actually not much to it.

It uses 6 motors and 2 servos.
The 2 x servos are for the pan and tilt camera,
and the motors are :
2 x motors for the final drive
1 for turret rotation
1 for Depression and elevation of barrel
1 for winding the plunger back for the gun.
But that’s leave a bit of problem, I have the
Arduino Servo & Motor Shield for 2 Servos and 4 Motors (Adafruit)

Which means I fall short by one motor control otherwise it would be perfect. Size weight control all excellent.
I thought about replacing the gun mechanism with a solenoid type of device, though good in theory I’m not sure, anyway that’s the least of my concerns it tertiary to the actual use,( though slotting a bb in the rusty sheriffs badge of a squatting feline at a 20 paces would be pretty kewl, and rewarding for that matter ).
The wireless control comes from marrying the Arduino with 2 Xbee pro’s

On 2 x Adafruit XBee Adapter Kit - Point to point and mesh wireless networking Arduino

Cheap kit / Prepare to solder
They rate at about 1 km
I have been able to control the Pan and tilt using Processing and Arduino sketches. Very simple, tutorial. Be careful though so far I have only found my Mega AXT has been able to supply enough power to the servos and servo board at the same time, I have now 9v external powers on each and every board and it works spot on. This is one of the reasons I’m looking into a power distributor similar to RC helicopter boards, either buy one or make my own.

[Swarfing]

Why not go for something like this? we are using one for an octopod we are building.

32 Channel Servo USB Controller board for arduino MCU PIC | eBay

[Fivetide]

Why not go for something like this? we are using one for an octopod we are building.

32 Channel Servo USB Controller board for arduino MCU PIC | eBay

Can you run motors off the board ? I'm worried about the amount of heat and load on it, aircraft are great as they blow air over electronics constantly

[Swarfing]

Caution is always good advice. We are actually using a 16 channel version and it is not being built for speed so heat is not a big issue but a fan would not go a miss.

Check out the octopod builds and you will see what others are using. You can get a lot of servos running ok on these.

[Fivetide]

You can get a lot of servos running ok on these.

what about drive motors like ones on the tank ?

[Swarfing]

DC motors may be a problem with this type of setup?