I have a question
I am going to connect it to a picaxe would it work.
The motors stall current is 2.1 amps can the motor driver handle that?
look for the L298D. as I'm also gonna use it for same goal. it can handle 2amp each motor (with headsink). also ad the diodes as described in the datasheet.
Where can i buy this ( I can not find it)
Except some dutch shops i didn't know actually. But a quick google search says solarbotics sells it: http://www.solarbotics.com/products/l298/
They also offering a complete kit to make it some easier (as it can be a bit difficult for a beginner to hook up a motor driver) http://www.solarbotics.com/products/k_cmd/
they have it on ebay too, L289N (i think the letter refers to minor variations in the hight of the package)
can a TO-220 heatsink be used with this?
2A per motor. The '298D is around 800mA IIRC. The L298N has a strange staggered leg arrangement. Get the breakout board or it's a hassle. There is also the L298HN that lays down flat if you find it too tall.
My mistake. I indeed mean the L298N, also called multiwatt version in the datasheets. you have to bend the pins a bit to make it fit into a standard pcb. and like JAX is saying, soldering is a bit difficult to do. that board from solarbotics is worth it.
for heatsink I have sawn an old pc heatsink into half. if youre making a metal frame for your robot you can use that as a heatsink. Only remind you that the metal outside of the l298n is connected to pin 8 (ground). but I don't think the heatsink has to be that big as that 2,1 amp you're meassured is max. and on my big blue robot it takes that current continue.
EDIT: just meassured that my motor with tamiya tracks turning freely uses under 400 mA. with some resistanse the double. you don't need such a big heatsink. a small one will do.
No it won't. I had the same problem with my gearbox. I built my own motor driver and they were still to much amprage so I ran them using PWM to keep the current down. Then I was on the Pololu site and I found they have higher voltage lower current replacement motors and they work great.
Here is the link and I hope my little bit of exprience has helped.