[mbartell]

I went to radio shack and got the relays there. they are 6volt 1 amp. 3 volts will not trip them. Match the relay with the power you are using- 2 cells is around 3 volts 4 cells is around 6 volts, depending on the battery. The relays were also around $3 a pop, and the lowest voltage they had was 6V. The one amp rating is for 120 VAC, or 12VDC, according to the side of the relay, so I figure I'm safe. I'd order them from the tinracers site, if I were doing it again, but anyway....

The PCB isn't that important, all you have to do is put the original leads to the motor to the signal post of the relay. Put a diode in between the signal post and the - on the relay, or you will get a VERY loud buzz. The diode allows the output to be - when you switch directions, and keeps it from shorting out when the output is + The motor leads are now just a signal to turn on the relay, and the relay puts full power to the motor, without going thru the pcb.

All you have to worry about is that the new motor leads from the relays go to the correct tab on the motor.

Other than that, you should be able to follow the wiring diagram for everything you need.


The only problem I've had is soldering wires to the contacts on the bottom of the relay. they have a tendancy to break off and leave you with a little nub that you can barely solder too. Some hot glue to keep the wires in position will help.

The only other problem I've had is trying to controll it. All the mini cooper (tyco fast gear) does is spin on one front wheel. On a grippy track, it'll go stright, but if you turn, the car rolls- for a long time. I'm using 4 1800ma AA batteries and a timiya torque tuned motor... I still haven't hooked up the super-duper (can't tremember the name) one yet.