BIQU A4988 Stepper Motor Driver Module - 5pcs Pack with Heat Sink for 3D Printer, CNC Machine, RAMPS 1.4 Controller - DIY Electronics & Robotics Projects

Suggestions:- Use a capacitor for over 3.3 V- 5V! reason: I ran mine without and caused a small electrical fire. Tried it with the correct one, no fires yet!!- DON'T RUN LONG! reason: It gets hot!! Will melt something and/or catch on fire. You could mess hardware up.- DON'T STACK TIGHT! reason: It gets hot!! Will melt something and/or catch on fire. You could mess hardware up.It works, but the risk of fire is more prevalent than in any machinery I've worked with.The dude in my tutorial did none of these things and still had no fires, but I'm convinced he is a low-level deity so take it at your own risk.So I only have tested 2 so far. Out of all my searching on how to use them for a homemade cnc like machine I'm doing I've had a couple complications. One documentation is limited. It took me forever to get them turning to some raspberry pi code I had then after messing with the circuits a bit the code isn't working as intended. I only messed with the driver to see why it activates when any part of my body goes near it and no solution has been found. After test after test I've seen lots of weird messups happening. It was working fine at first but when I unboxed the second one it's been running into the same problems.I have had some strange problems with my printer so picked these up to swap the drivers and see if it would help. They did fix one of the problems and have been running fine since. These are fully assembled and a good value. The only thing that could be an issue is the heatsinks will probably end up sitting on some of the capacitors as well as the chip. The thermal tape seems to isolate it but I don't like the heatsink touching other components. It is a bit difficult to get the sinks to position where they won't touch the other board components and even so the tape is a bit rubbery so they never stay solidly in position. I am considering using some thermal glue instead of the tape they provide with the sinks. This is not a problem specific to these however, I have seen it with many stepsticks I have used, just something to consider when applying the sinks.Upgraded away from the fire provoking RAMPS board to something better. Got a bunch of new stepper motor drivers to allow me to just swap all the electronics at the same time. These worked fine. Just wished they had a tad bit more documentation with them. Like how to set the motor current using the potentiometer. Google is your friend, but a 1/2 sheet of paper would have been helpful.Seems to be good quality. Haven't got to try them yet. I have a project for the future that I'll probably use them for. I have some more and I just wanted to have some extras. I would buy more if I needed them.If you are looking for a simple microstepping motor controller, these are them. The logic side can be 3.3 or 5V, and the motor side can be from 8V up to way too much. Since these are current limited, higher voltage is a good thing because it defeats the back EMF and results in good torque without overheating. Each is individually packaged in anti static, pins are pre-installed (no soldering), with a heat sink, and they could be used with a socket. The pins are clearly labeled on the bottom side, use the manufacturer data sheet to understand the mode settings.The product is well documented on the web and worked perfectly on my first try with an Arduino Nano demonstration project. It reverses direction and does a good job with sub-stepping.The work once you have them set up right but the potentiometers on these are incredibly easier to shear off. Broke one after only a quarter turn and another fell off in the electrostatic bag. Be very, very careful and lucky or I could see all 5 going to waste before even really getting started with whatever project you're working on.