If you’re planning on building a CNC router, plasma cutter or waterjet, you are going to need at minimum a 2-axis stepper motor controller. The Geckodrive G540 is a very versatile controller with many great features. With an MSRP of only $299, you may be able to find lower cost units out there, but none with all of the features of the G540, or the proven track record. The firmware of this drive controller is error free and hasn’t needed an update in five years.
I got one to run my CNC router and I’ve been very happy with the results. The G540 provides 4 axes of stepper motor control and four analog inputs that can be used for anything you wish. Most commonly they are used as limit switches, but they could also be wired to sensors to detect other equipment conditions that you may want to automatically trigger a shutdown. If used with a waterjet, you might want to shut down if the water or abrasive runs out. If used with a plasma cutter, you could scavenge the signal from the fault detector and use it to stop the process.
In addition to the four analog inputs, the unit also has two outputs that can be used to trigger relays. One could start your router, your plasma cutter or your waterjet pump. The other could start dust collection or some other accessory. There’s also an input for an emergency stop. Finally, the unit provides an output designed to control a VFD (Variable Frequency Drive) and that can come in very handy on a CNC router.
There are a few drawbacks though. It runs on a parallel port. Modern computers typically still have them on the motherboard, but you’re on your own to find the ribbon connector the bring the signal to the outside world. Most folks would just buy a parallel port adapter. You’ll notice it uses DB-9 connectors to connect the drive controller to the stepper motors. They don’t mention it in the manual, but these are not your ordinary DB-9 connectors. They are heavy duty units that are made to handle the current passing through them. If you talk with their tech support, they will tell you to make sure to use the DB-9 plugs that come with the unit. They said neither the connector nor the wire of a standard serial cable are rated for the kind of current this application draws.
When I wired up the G540 and connected to it using MACH3 CNC control software by ArtSoft, it worked flawlessly from the first time I fired it up. MACH3 needs a hardware profile to talk to any kind of controller and Geckodrive provides one written especially for MACH3. Just load the profile when you start MACH3 and it works. Everything about the G540 worked exactly as described in the manual and I couldn’t be happier with it. Their tech support was very helpful, and if you call at the right time I think you get to talk to the guy who actually designed it.
If you need 3 or 4 axes of control and like having the analog inputs, relay outputs and VFD control, I would definitely go with a Geckodrive G540.