FreeCAD tools and settings for CNC 3018 Pro

I recently bought and assembled the CNC3018. I have never owned a CNC before and I was unpleasantly surprised by the lack of free and easy to use software to produce CNC jobs. So I had to learn FreeCAD, the only open source software known to me which can be used for this purpose. In this post I added the two types of tool bits supplied with the CNC to FreeCAD's library and I will attempt to produce various jobs in future posts.

CNC machining is a complex process and its workflow depends on a lot of interrelated parameters unknown to beginners. Setting them properly is an absolute requirement to complete a CNC job without breaking valid bits, ruining the work piece or damaging the machine.

CNC 3018 Pro Z axis coupler adjustment

The first thing people tell you when you start doing CNC is that you will break some bits. It happened to me too. I checked the gcode before sending it to CNC so I wouldn't ram the bit into the work piece or the base plate. But, with my CNC 3018 Pro another thing happened. The spindle could no longer be lifted (Z axis movement failed).

CNC 3018 comes as a kit. With the exception that in the newer batches of this product, they decided to ship it with preassembled Z axis assembly. Obviously, I assembled the machine and didn't pay any attention to the Z-axis. Until I had to. The lead screw slipped from the shaft coupler during a job and the bit nearly got to the base plate before breaking. Then I realized there were some problems with the Z axis assembly.

Spindle at its maximum Z height with short shaft stepper

Update GRBL firmware on CNC 3018 Pro

CNC 3018 Pro is a low-cost CNC router that should be used mostly with wood and acrylic plastic. It can also be used to mill PCBs and cut soft metals like aluminum with proper settings. The machine uses both metal and plastic parts. Electronics is based on a custom made ATmega328p board with A4988 stepper drivers. Spindle uses a common DC775 motor fitted with ER11 chuck.

I recently bought one from Banggood (I chose the version with offline controller because it allows me to load gcode from SD card and use the CNC without a computer next to it). To my surprise it came with an old version of GRBL firmware (0.9j) so I started gathering information about how I can update it.