Category Archives: CNC

MyDIYCNC Desktop CNC Machine $20 GRBL Resurrection

About 8 years before the writing of this article i purchased a CNC machine from Amazon created by a company called MyDIYCNC. I was interested in the technology and the price was right at only $250.

It was easy enough to assemble and get working with Linux using their FabCAM software. Well, so it seemed at first…

When the z-carriage would retract, it would skip some steps once in a while and eventually drive the tool head into whatever I was trying to mill. While the company’s customer support was responsive I could never figure the issue out and the project got shelved.

Long story short the company is no longer around but the machine was. Sitting on my shelf, sadly doing nothing.

Then one day while shopping for 3D Printer upgrades, I ran across this Arduino kit on amazon that will replace the proprietary brains, motor controllers, and software with a well supported open source system, GRBL.

I put the Arduino and drivers into this 3D Printed enclosure:

I used the power supply that came with the MyDiyCNC kit as well as the original spindle relay. The two wires on the right go to the spindle pins on the Stepper Hat:

I soldered some female plugs from jumper wires onto my motor wires and attached them to the motor driver output. Color order from top (reset button side of board, see photo) is Blue, Red, Black, Green:

I hooked the 12V+/- output from the power supply to (yellow+, black-) to the controller hat. This is also where I pulled 12V for the 40mm enclosure fan.

Don’t forget to put a jumper on the enable pins (right of reset button).

Once everything was all hooked up I adjusted the motor controllers amperage to 400mA (for the stock motors that came with the kit, your mileage may vary) using this guide.

Now you just need to flash GRBL to your Arduino and get some software for your computer. Here are some helpful links and files that go me through the rest of the setup phase including jumper settings for microstepping:

The last tweaks to get it to work correctly was to set the X, Y, Z max speed to 350mm/min (Firmware Settings) and 1/4 micro-stepping (Jumper under motor driver).

Now you can calculate your steps per millimeter here.

Finally, the software to control it.

I have been using OpenBuilds Control and their integrated CAM software. It works fairly well, though the GUI is prone to crashing. Upside is that when the GUI does crash, the job still completes. Unfortunately he crashed GUI can make it difficult to find perfect zero again.

Universal Gcode Sender will definitely play with GRBL and control the machine. However I have yet to use it to actually run a job. I will post updates after I give it a try.

Feel free to post any questions in the comments section below!