design specification

design specification: CNC design

the main function of the product and project

  • a CNC milling machine with 4-axis control: X/Y/Z for moving the milling tool, 4th for experimental use like rotating the milling object/tool
  • the CNC machine should be able to cut plastic, wood and make PCBs
  • we would like to be able to cut in aluminum too, as we would love to be able to design metal gears, and possibly in the future, construct a new and improved CNC machine using this one
  • the CNC machine should be quickly and easily built – we are interested in experimenting with the machine as well as building it, so we should finish a CNC milling product within the given time scope (13 weeks), but also have some time to experiment with it – also we would like this project to function as a “cookbook” for other people interested in building a cheap, but functional CNC machine – our level of communication is aimed at engineering students and other technically interested people, so we will explain what we are doing, but we won’t explain the most basic technical terms

flexibility and openness

  • we would like to experiment with different milling heads and techniques; mounting dremels, painting units, foam cutters etc. on the frame, so the mounting of the milling heads should be flexible and open
  • we base this project on open source software and tools, we believe in sharing ideas and experiences and invite everybody to join in

cost

  • the overall budget for this machine is approx 5000 DKR (approx 666 EURO) – it would be possible to cut cost even more, by constructing all parts from scratch, but this would take too long time, and therefore is impossible within the given scope of time. BUDGET NOTE: more than half of the cost of the machine is the pre-built X/Y frame bought used on ebay — this means that the complete machine could be much cheaper (approx 1700DKR / 227 EURO) total

the main overall dimensions of the product

  • X/Y: approx A3 – big enough for many designs, but still a compact cnc machine
  • Z: min 10cms

the main materials used

  • steel for the mechanism
  • preferably plexiglass for the safety cover – something seethrough, so there is a minimal chance of users removing the cover from sheer annoyance

user requirements

  • the milling machine should respect standard g-code, that is it should be programmable with major CAD/CAM and 3D software (i.e. PRO/E)
  • the machine use should be reconfigurable for experimental CNC designs
  • the size of the machine should be as small as possible, yet giving us the largest possible milling area
  • the machine should be easily moveable: in modules and possible to transport in a standard car or christiania bike

source of power

  • the cnc should run on 230V, but a 12V possibility would be a nice addition

safety and legal requirements

  • this is a dangerous project! extreme caution must be taken when testing the machine, also a bare minimum of safety we must ALWAYS be wearing safety goggles when running it. when cutting aluminum or harder materials a safety casing should be applied.

environmental considerations and requirements

  • we prefer to use as many recycled materials as possible – both to cut cost, but also because we believe in recycling