Entry level CAD/CAM

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Revision as of 19:36, 29 October 2017 by Rob Kam (talk | contribs) (Rob Kam moved page ShapeOko Induction to Entry level CAD/CAM)
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The Shapeoko2 is the entry level LHS CNC machine. It is more often than not used for PCB Drilling and 2.5 D milling. This page outlines the skills needed to run it. To start you probably need to have produced a CAD drawing and its g-code.

It is not access controlled, if you come down on a Thursday some one will show you where the on switches are for the machine and computer

CAD/CAM

Using a CNC requires a bit more background knowledge or learning than a laser cutter or 3d printer. You should have some knowledge of CAD and CAM concepts and have used a CAD/CAM package such as Autodesk Fusion (free, works on Windows or OSX) or other package capable of generating g-code for CNC machining. We will be happy to help with explaining concepts but depending on your previous experience there is quite a lot to learn so you will get the most out of the session and the machine if you do some independent reading / practice.

Pre-requisite competencies

In particular before coming you should learn a bit about:

  • The difference between CAD geometry files (i.e. DXF, IGES and STEP), and tool path files (i.e. G-Code)
  • Cutting materials – cutter speeds and feed rates – dependent on what you want to cut. There are many examples posted by Shapeoko users as a starting point.
  • Any CAM package, Fusion 360 is a good one if you are not sure. You should try generating a tool path with a particular cutter, checking the toolpath visually and by simulation if your CAM software allows it, and finally posting the G-Code to the a g-code file (i.e. .gcode extension).
  • XYZ coordinate systems (on the Shapeoko, x is left to right (+x is travelling right), y is towards / away from you (+y is travelling away from you), and z is down / up (+z is travelling up)
  • Concept of finding datum of the workpiece, for instance touching off the tool in x, y and z (z is very important)
  • Checking a CAM toolpath by simulating the cut, and also checking the extents of the tool path to make sure it is not going to run into any fixtures or the bed of the machine.
  • You will need a LDAP account to login to the machine – further information on creating an account at https://wiki.london.hackspace.org.uk/view/LDAP#What_can_I_use_my_LDAP_account_for.3F