As I mentioned before, this hobby is not cheap; there are so many expensive components that you cant just make yourself and most of them are liable to break the first time you enter the arena. I do know the basic principals behind robot electronics as in what bits you need, bare minimum, to get it to go and what each bit does but beyond that my knowledge is limited.
[At this point in time I do have quite a few parts and have learnt a lot since I started. I also have finally figured out the wiring arrangement for the robot to a certain degree and begun to solve the problem I mention at the bottom of this post. but progress is slow.]
I knew that I would need a transmitter and receiver, the bit that makes the robot remote controlled. Batteries, motors and wheels were obvious and I also knew that I would need some relays to control the night voltage motors with the low voltage receiver.
For the receiver I have brought a Spektrum DX6i transmitter and receiver set. Spektrum are one of the top manufactures of digital transmitters in the world and all there transmitters use a system called DSM 2. This is a very clever piece of tech which means that there is almost no interference and under 95% of circumstances there is none at all. This is now seen as standard for all combat robots above beetle weight for safety purposes but it is also the easiest to use and its fairly cheap to considering its advantages over the old 27 Mhz analogue transmitters.
The DX6i is Spektrum's lowest cost transmitter with a digital mixing interface at around £135. There is the Spektrum DX5e at about £90, which is Spektrum's cheapest DSM 2 transmitter. This uses the traditional array of front mounted switches to do the mixing. As a result it is cheaper and works perfectly well but for fine tuning the handling of the robot and full freedom over what controls what on the transmitter the DX6i is best.
The batteries are still posing a problem but I know that I want 2x 7.2v Nicad battery packs to run in parallel giving me 14.4 volts. I want the 14.4 volts to run the 4x RE 540/1 Metal Gearbox 50:1 motors. These operate at between 6v and 16v and draw around 0.2 amps each when loaded.
The wheels are currently 4x Treaded Rubber 101mm dia Wheels PK 2. I have yet to figure out how to attach them to the motors (I am going for a direct attachment onto the output shat as the motor incorporates its own gear box)
I have been quite lucky with the chassis. My university was replacing a load of old science lab desks. I got in there quick enough to ask them to give me two before they went off to the scrap-heap. The result is a 30mm, with 1.5mm wall thickness steel box section chassis which is very strong.
I also brought 3 Battle Switch relays to control each side of the robots drive train and the weapon. (Have now gone for a modified version of the 2nd Flipper/Spinner robot, without a flipper)
It seems right to tell you at this point how much this has all cost...
Just under £300.
If you go for the DX5e that drops to nearer £250 but its still a lot of money.
And now the crushing blow to my hopes. After talking it over with some electronics friends at university out turns out that the relays are all but useless to drive the robot. I can use one for the weapon but unless want the robot to 'handle worse than a school bus' I would need to by some kind of speed controller.
So today it has all ground to a halt once more until I can find a suitable pair of speed controler's.
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