HiLetgo 5pcs A4988 Stepstick Stepper Motor Driver Module with Heat Sink for 3D Printer Reprap Suitable for Mendel Huxley Arduino

As long as you match them with the style of motor you own, they work perfectly.

Fast delivery, good product.

Perfect for my needs

Overview: This driver suits my need. All tested modules were functional. I agree with prior reviewers: the on-board trim pot is weak and easily broken. I damaged one while adjusting Vref, rendering the module useless. I was more careful with others. If you run current near the module's max, the heat sink's size is suboptimal, but its the largest that will fit on the IC.Warning:1) Do not use the module without first setting the Vref below the max current for your motor. The Vref trim pot is in a random position, ranging 0-1.2v. All of my modules had Vref set to deliver more than the max current for my stepper. 2) Be sure to place a jumper across the RESET and SLEEP pins. Motor may not work without this.

how do you apply the heat sink w/o shorting anything? way too tight.

Here's what starred items Amazon wanted me to rate for these stepper drivers.Noise level?Adhesion?Warmth?The vendor should get on them for this nonsense and the poor ratings it might bring.I guess they know not what they sell!But I'll say in defense of the seller and the product that ...Thes are pretty generic, and these work as expected and the delivery was fast.

40% of the ones I bought didn't work at all, and 20% of them are fully shorted out. Not worth the trouble. I wanted to love them, but I really don't.

Just as loud as big brand a4988's (loud) and have okay heat dissipation but are very reliable, and will get you out of a pinch if any of your quieter steppers decide to die.