WHEN: Most Friday evenings. TIME:

10 June 2009

Costa's breadboard controller - part 1

Some gentle persistence from Chairman Costa got me to scratch out the previous start of an "easy to follow Assembly" controller, commissioned by him so long ago. This is the Parma Turbo and it is hoped to do same with the new good value MRRC controller. Thought it worth dealing with the basics without the clutter of hook up wire, first. Of course this is where the steam ran out before so hopefully this motivates the part 2 for final completion. Click on the pic and study the large version closely before reading on. Costa's requirements in bold:

1. Minimum butchering of the controller case. With the above approach there is virtually no dremel cutting of the a Parma Turbo case, although a standard case would have to opened at the top ala the Parma Turbo space for the frame. Three pimples are removed from inside the case to clear the transistor and new spring position. Easy to spot when closing the case together.

2. Simple layout to follow. The brake pot is just above the brake stop and the sensitivity pot is a similar short distance away from the full throttle hook up, requiring very little hook up wire and a circuit layout which can be followed by someone with no electronics knowledge at all. Obviously all the long spiky arms will be cut off the potentiometers after the hook up wiring is complete, so there will be no pricking of precious fingers.
3. Minimum parts count. The transistor uses the Turbo frame as a very efficient heat sink. The frame kindly already provides the necessary holes, which only need a some extra opening up to prevent shorting of the two hook up legs, which are bent over to clear the case. A cheapie transistor insulation kit is a must to prevent electrical shorting against the frame.

4. Minimum drilling. There only two extra holes drilled in to the frame to hold both the fibre potentiometer board and the wiper board. The resistors are first soldered in the back of the wiper board whilst being bent flat. That means the board can be located very low down with no fouling of the upper case by the wiper arm.

5. Relocation of the trigger spring (not specified but essential). This is very important to ensure effective returning back to the brake stop. The frame also kindly already provides another hole in to which a new spring holding point bolt is locked. The original spring locating arm will be bent over to hold the main cables in place. Costa's Turbo controller kit had the best spring supplied that I have ever seen in a Parma controller, by the way - way better than the old barbed wire Turbo springs and saves pinching out of old Economy controllers.
6. Minimum manufacture of parts. The pre-made wiper board is available locally and online and is well worth it to simplify the project. Thus the only element of home manufacture is the small piece of board to hold the two potentiometers and bolt to the controller frame at the two points mentioned. This can really just be eyeballed off with the pots themselves before drilling and cutting the board.
That's it! Roll on part two wiper arm and hook up.

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