meet the monster

my vintage industrial cnc-router is a versatile little beast. From engraving to free-form 3d routing it can handle a lot of different tasks and materials.

the story

gravoGraph_machineIn the 80’s (yes it’s that old) the french made Gravograph VX 2 was a flagship industrial engraving machine used to engrave large volume stuff like public information signage and serial numbers. It’s extremely sturdy (one of the most critical qualities of a CNC-mill) and has a very good precision and speed. It seems to come from a time where built-in obsolescence hadn’t been thought of yet apparently since i’m still using most original parts, even the motors and spindle. It had already been modified by the previous owner with a spindle fitting that allowed for many standard milling tools to be mounted. It’s not really a 3-axis cnc mill by design but a 2D (XY-axes) but it had a stepper motor on the spindle tray (Z-axis) as well so i went ahead to try convert it to a full 3-axis machine. I threw away the old PC unit running a primitive DOS based lettering software (if you can even call it that) and many years later, with the help of another expert friend, finally managed to get it to run on a ‘modern’ PC running current industry standard software.

 

what’s the monster up to ?

Now that it’s under full 3-axis (XYZ) control there are many uses for it: it can draw, cut, slice, drill and possibly even squirt glue or airbrush .. and in a very precise fashion. At it’s most basic level, it does what computers do best: handle repetitive tasks with utmost precision. Drilling a thousand holes or routing a hundred profiles, cutting weird shapes at perfect angles and precise distances are task difficult or tedious to accomplish manually and easy to do on a CNC. Personally i quite like the challenge of the more advanced discipline of cutting a solid freeform object out of a block of some kind of raw material but many times the worker bee aspect of CNC production comes in very handy as well.

 

capacity

  • max working area: 65×50 cm (longer pieces can be machined if they fit under the portal since the machine is open front and back)
  • max workpiece size: ca 55×45 cm
  • max workpiece height: ca 8-10cm
  • spindle speed: ca 15-20k rpm
  • precision: ca 0.017 mm
  • max cut depth: depending on material/design/tools but usually not more than 5cm and not more than 2-6mm at a time
  • biggest tool size: 6 mm (12mm for special ‘light’ decorative applications only)
  • smallest tool size: 0.5 mm
  • finest possible detail: usually not less than 0.1mm, but it really depends on the material and tool used. the ‘thinnest lines’ you can do realistically on most materials is usually around 0.5mm. this has to do with the fact that most materials are not completely flat and that the material and machine parts move a tiny bit under workload.

 

my software

i mostly use Rhinoceros and Grasshopper to prepare the models and curves and Rhinocam to generate the machine instruction files (called GCODE) necessary to operate the cnc and MACH3 as the control software. Although i have played around with some opensource solutions they prooved to be rather experimental so far and pretty annoying and sometimes dangerous to work with.

 

your software

as stated before you don’t necessarily have to understand my software and are free to use most standard/common design software to generate your artwork. The common software for most 2D CNC jobs are probably Adobe Illustrator if you’re an artist (photographs and photoshop files have to be converted to vector art to be used) or AutoCAD if you come from an engineering background, and for 3D objects any software that can export in any of the standard 3D fileformats [OBJ, IGS, STL (preferably STP), FBX, Collada, …] can be used. However, you should probably be prepared to rework your files so that they can be used in mechanical production or be willing to pay me for doing it for you. Especially taking a 3D model from the virtual to the physical requires additional steps and some times different approaches to be taken to make things work out. I will always encourage you to rework your files yourself with my help and guidance but can do it for you as well if you prefer and many times that’s the most practical solution.