Build Log: Robotising a RC tank (first attempt)

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

Attachment 7005

*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:

Attachment 7006

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

Attachment 7009


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.

Attachment 7010 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

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Originally Posted by blackburn mark

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

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

Quote:

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Originally Posted by blackburn mark

Attachment 7010 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

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Quote:

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Originally Posted by boldford

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

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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 !

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 :thumsup:).
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.

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

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Originally Posted by 2e0poz

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

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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

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.

Quote:

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Originally Posted by 2e0poz

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

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what about drive motors like ones on the tank ?

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