Nigel Lawton OO9 Simplex part 4 - wiring up and making it run.

First of all I should state that I hate wiring anything up, and although I'm happy soldering brass and nickel silver kits together I really dislike electrical soldering. Go figure...

The motor is rated at 6 volts, so a resister is needed to drop the voltage down. So first of all a piece of .8mm PCB is trimmed down to 2mm x 4mm, gapped and glued the l/h chassis frame;

Then a tiny surface mount resister is soldered to the PCB. The instructions suggest shorting one side of the PCB to the chassis with solder, I chose instead to use a tiny piece of wire cut from the motor lead to connect the r/h side of the resister to the chassis. Instructions are for the guidance of the wise and the blind obediance of fools... (not that I'm particulary wise!) The other side is connected to the motor;

At this stage I felt it wise to make sure the wiring did actually work so out came a controller, and with one crocodile clip connected to the chassis and the other to the black wire power was applied and thankfully the motor turned as it should.

To make the pick-ups a length of phosphor bronze is soldered on edge to a 1.5mm x 4mm piece of PCB;

This is then glued inside the l/h frame side, connected to the motor, and the wiper formed to shape;

In both instances the resister and wiper are soldered in place with electrical solder, then the wiring soldered in place with 145 degree, which in theory prevents the initial joint from coming undone. Of course I did unsolder the wiper from the PCB trying to solder the black wire in place... second attempt worked fine though so the theory is sound. I never seem to make electrical joints as neat as I do elsewhere, despite using a tiny smear of Fry's powerflow flux.

With the wiring finished the chassis was re-assembled along with the drivebands, oiled and then the task of fettling it could begin. The motor is tensioned with a driveband which can be adjusted by bending its retaining lugs, it needs far less tension than you'd think. I started out by leaving off the tensioning band, unhooking the drive bands so they're loose on the axles, and placing the chassis on my test track (grand name for an oval of Kato Unitrack) and just letting the motor run without load for about half an hour in each direction. Then I fitted the tensioning band, adjusted the tension until it felt right and drove the pulley shaft smoothly. Then the drive pulleys were fitted over their pulleys and, with the chassis weighted (a couple of lumps of Blu-Tack and a shiny penny) it moved under its own power for the first time. It ran rather noisily at first, and needed a fair amount of power, but with after a few laps of the oval settled down. It now runs quite smoothly, and I'm sure will only improve.

Here's the finished chassis, note the tensioning belt over the top of the motor;

So far I'm very pleased with this kit. Now to start on the body.

Paul.