This tiny heat sink fits on a Surface Mount Device, such as the chip on the Pololu Stepper Driver (A4988). We add a special 3M double sided tape impregnated with heat conducting material
For the heat sink alone:
Dimensions 6.3 x 5.1mm, 4.8mm high
Thermal Resistance 123 degC/W
Color: Black

These stepper motor driver boards are compatible with the Makerbot mightyboard (Makerbot Replicator 1, 2 and 2X motherboard, rev E, G and H). Our version includes a heatsink attached to keep the botstep cool and less prone to overheating.

This board is a drop-in replacement for the A4988 Pololu board. It is superior in that it can handle 1.5A instead of 1A without extra cooling, and rated upto 2.2A with a heatsink and fan. It also has microstepping resolutions down to 1/32 microsteps (instead of 1/16th)
Comes with a header strip which needs to be soldered on for mounting to a RAMPS shield, but is left off so you have the option of using it in a different way, such as attaching to a ribbon cable or breadboard.
Supplied without a heatsink (available seperately).

This board is a drop-in replacement for the StepStick A4988. It is superior in that it can handle 1.5A instead of 1A without extra cooling, and rated upto 2.2A with a heatsink and fan. It also has microstepping resolutions down to 1/32 microsteps (instead of 1/16th)