Topic: ElecFreaks 3D Printer: A4988 Thermal Design
A4988 stepper motor driver does play a very important role in the 3D printer owing to the fact that its performance directly affects the printing accuracy, print quality, and stability. Since our motherboard uses a 24V stepper motor driver, A4988 driver chip generates much more heat than a 12V motor. Therefore, the design of an A4988 circuit with good heat dissipation to allow steady work is the focus of the entire work.
The initial version of A4988 driver generated growing heat and had difficulties in cooling and long-time work. A4988 driver module has undergone generations of evolution with the first generation limited to only a few hours output of 100mA driver current. Now to our great satisfaction, it supports stable 400mA current output for over 24 hours.
In the following part, we will share some of the experiences we have accumulated in the process with you.
A4988 dissipates heat mainly through the bottom bonding pad, which must require punching for cooling. Our initial version is a two-board design with 9 through holes, 0.6mm as their diameter on the bottom layer, aiming to transfer heat to the bottom copper sheet through the 4 through holes and disperse it.
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Schematic Diagram
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