The test results in full are below:
Comparison of Stepper Driver boards
Thermal imaging tests carried out for Think3DPrint3D.
Thermal testing of various different stepper driver “shields” carried out using a test sketch.
• Sketch set to run 10,000 x 100us steps clockwise followed by 15,000 x 50us steps counterclockwise, with a 200ms delay between direction changes.
• Drivers were set to 1/16th microstepping with the current limit set to 1.25A.
• Drivers were run for 5 minutes and a thermal image of the driver shield was taken at the end of that time, while the motor was still running.
• No additional heatsinking was added to the stepper driver ICs.
• The motors were all the same model, unloaded, 4.4kg/cm NEMA 17 motors used on many 3d printers.
Drivers tested were as follows:
1. Stepstick - A4982 - TSSOP IC - 2 Layer PCB - 1oz copper
2. Pololu 1182 - A4988 - QFN IC - 2 Layer PCB - 2oz copper
3. Pololu 2128 - A4988 - QFN IC - 4 Layer PCB - 2oz copper
The old Stepstick tested as number 1 as almost certainly built using 1Oz rather than 2Oz copper and is dual layered rather than 4 layered hence the worst thermal performance. In addition the supplier has not published their design changes from the original Stepstick so it is hard to see how thermally efficient (or not!) that design is.
Pololu claim a 20% improvement in thermal efficiency between the 2oz 2 layer board (no. 2) and the 2oz 4 layer board (no. 3) for the A4988 which these test results support.
The "Ice-Blue" Stepstick which is similar to the A4988 4-layer Black Edition Pololu runs slightly cooler than the Pololu, probably due to the larger heat dissipation area of the A4982 TSSOP package.