View Full Version : Total novice seeks advice on stepper motor drivers

24-01-2012, 03:48 PM

I am a complete novice on CNC-machines and has in fact never used one before. That being said I have for a long time wanted to make a desktop sized, cheap CNC-machine to learn the basics of how these work and might even make a few simple things with it (like milling PCB's, cutting thin metal sheets and such). I have therefore been googling a bit and looked at several DIY-projects. My main problem with most of the DIY-builds however are that they are too expensive for me (being a student means that money is a bit tight, sadly).

Being a complete dummy when it comes to electronics does not make things easier, since my biggest problem with this project is to figure out what electronics I need to drive my stepper motors and router. So far what I have managed to understand is that I will need driver boards for my steppers, as well as a breakout board so that I am able to interface the driver boards with my computer and the CAM/CAD software that I will be using.

I have found a driver board and a breakout board on Ebay, that seemed to fit the bill (for a low-cost as well):

Driver: http://www.ebay.co.uk/itm/L298N-Stepper-Motor-Driver-Controller-Board-Module-DC-/230635902504?pt=UK_AudioElectronicsVideo_Video_Tel evisionSetTopBoxes&hash=item35b2f89628#ht_5778wt_1163

Breakout board: http://www.ebay.co.uk/itm/CNC-5-Axis-Breakout-Board-Interface-Adapter-Stepper-Motor-Driver-/180753543086?pt=UK_BOI_Industrial_Automation_Contr ol_ET&hash=item2a15c02fae#ht_6701wt_905

From my understanding I will need 3 of the driver boards a long with 3 stepper motors (have the motors from an old printer I scrapped) as well as a power supply, a router of some sort (dremel perhaps?) and of course the breakout board.

My questions are: "Will I be able to make a small desktop sized CNC using the above mentioned components?", and "Will the driver boards or the breakout board cause any compatibility problems with programs like Mach3?"

I hope my questions are understandable, and that you might be able to answer my questions. Thanks in advance!

25-01-2012, 10:34 AM
I'm also a student...
I started off using an old unipolar driver (compucut) that I got from school on my milling machine. It was fine for the first few weeks but I soon got bored of the extremely low feedrates and I'm sure you would. Unless the machine is very small you need to be looking at higher voltage drivers (about 50V) and bigger stepper motors unless you've been very lucky with the printer. For instance the m542 drivers.

The driver you lined to on eBay is actually only half the driver, it doesn't have the signal processing to convert step/direction signals to the correct sequence to spin the motor. It's effectively just an amplifier. Not much use...

What type of 'thin metal sheets' are you intending to cut? Unless it's very very thin you're going to need a very rigid machine.