Using Toy motor with ARDX CIRC03 - Motor will not spin

Hi, I have successfully followed CIRC03 from the ARDX Arduino Experimentation Kit and got the included DC motor to work correctly.

As a further experiment I tried to use the same circuit with a motor which I pulled out of a cheap toy car, it is smaller and looks similar to this -http://www.nkcelectronics.com/assets/images/09608-01.jpg

The toy motor will only spin if I twist it a little to get it started, why is that? Is there a modification I can make to the circuit to make it work with the toy motor?

This is my first post on here, so I am happy to move this question somewhere more appropriate if necessary.

Thanks

The toy motor will only spin if I twist it a little to get it started, why is that?

Not enough voltage on the motor.

Is there a modification I can make to the circuit to make it work with the toy motor?

Can you put more voltage on the motor?
Make sure your transistor is the right way round, check the one you are using has the same pinout of the one used in the tutorial.

Thank you for your help, I apologise for the noob questions.

I am using an arduino uno with 5v and 3.3v outputs, how can I increase the voltage with this setup?

It could be voltage - the motor supply would then need to be larger (just the motor supply, don't
put more than 5V on the Arduino Vcc).

Or it could be insufficient current for the motor, in which case first replace the 2k2 resistor on the
base of the transistor with a 220 ohm resistor, and if that doesn't get it going it could be the
power supply can't give the current. How large is this motor?

The motor is a little toy car motor, I thought it would only require a small amount of power due to its size but I have since read that cheap toy motors can be inefficient and therefore require more to power them than you would expect. I'll hook up an external power supply to the motor (sharing the same ground) to see if that works as discussed here - http://itp.nyu.edu/physcomp/Tutorials/HighCurrentLoads

I'll also stop being such a tightwad and buy a couple of cheap DC motors :slight_smile:

Thanks for your help.