The Story

The journey began a year ago when I purchased a cheap Chinese K40 Laser cutter and engraver from eBay for a 3d printing experiment. Before tearing down the machine for parts I decided to play with it for a bit of fun. I quickly discovered that the Chinese user software with encryption dongle was unusable in order to be anywhere close to productive. It is truly a complex Chinese puzzle, especially since it did not come with any instructions whatsoever.

The solution to this puzzle has lead to a wonderful story of adventure, including our latest development of the Super Gerbil CNC controller.

Having played with Grbl, the open source control software for CNC machines, I thought this might be a good match for the K40.  It would enable the use of Open Source design software and importing cutting files (dxf) from the internet for Laser cutting and engraving. No more limiting proprietary file formats! Looking back on this adventure, I must admit that having said was easier than done. However, I ended up with a working and very productive open source system that was just too good to keep it for myself.

engravings
Engraving examples
examples
Low, medium and high resolution engravings (from left to right)
The controller
The Arduino R4, GRBL based controller

So if you own, or plan to be a future owner of a cheap Chinese K40 laser, check this out as an awesome replacement controller!

I’ll be launching this controller on Kickstarter.com in July 2017, so we can achieve a cost-effective package for you:

Programmed and ready to use controller

USB key with the open source Inkscape plugin’s and g-code sender software

a wire harness for the optional control buttons pause, resume and abort).

Mini Gerbil, the successor of Gerbil Arduino R4

The 328PB AVR chip is more advanced than the one used in the standard R3 Arduino’s. Soon it became apparent that the cost of this processor and associated board is way higher than the Arduino R3. Despite the sophistication and lower production numbers, people just compare them hence it’s time for a better alternative. Since lasers are expected to run super fast in dither mode, we need to upgrade from 8 bits to 32 bits. The good news is that we succeeded in finding a cost effective alternative that can be produced at lower cost and performs better.

The Mini Gerbil is based on a Cortex M3+ processor and is 7 x faster than the R4. All components have been placed on one board to reduce the cost of the PCB and we cramped all smd components into a small foot print 53 x 80 mm. The Mini Gerbil does support ribbon and non-ribbon based K40s and other lasers. The firmware has been rewritten over a 3 months intensive period and is super fast and accurate (32 bits based math). PWM frequencies from 60 Hz to 80 kHz are supported and the stepper rate nears 100 kHz. Traditional grey scale engraving and other functions are still supported. Also works with Inkscape, Easel and LightBurn!

Older blogs:

The secret sauce that makes it work…

Technology insights…

Read my blogs on developing the controller

Newer blogs on firmware:

Grbl demystified

Super Gerbil development underway

Super Gerbil Specifications and details