Hi all,

So, after a bit of a break from actually buying a CNC router (a K2 KT2514) I'm thinking about using it again - to work wood this time. The goal is to produce a project-box with slots in for peripherals. Think: just like the back of a tiny PC case, where the PCI slots are...

Anyway, since I can't find a forum for "how do I do this" newbie questions, I thought I'd spell out what I wanted to do, and ask a few questions based on that. If this isn't the appropriate forum, please do tell me where to go (ahem, politely [grin])...

Here's the plan:

  • Start with pieces of 2x4 wood, 6" long, so the pieces are 1.5" x 3.5" x 6".
  • Use the CNC machine to:
    - Finish off the sides to be true and the top to be smooth, reducing to 1" x 3" x 5.5"
    - Hollow out the center, so what remains is a (0.25" thick walls) wooden box
    - Cut an elongated U (where the "PCI" slots will go) along one edge of the box
    - Drill holes in corners, partway through for top, fully through for base
  • Then turn over the 'top' piece and machine the other side. I need to cut a hole in the top of the box for an LCD, and it'd be nice to have chamfered edges for that hole as well as a bevelled edge around the top.
  • Put a 'top' piece and a 'base' piece together to make the box
  • Does this seem reasonable as a plan ?

Now I've done 3D modeling before (I've been using a 3d printer for a year or so, and it'll be making some parts for this as well), but I've never actually done anything on a router. So, some questions:

- I obviously need to match up the two sides when milling the top piece. How, exactly, does one go about doing this ? I'll be using Mach3 for the control, and DeskProto for the modeling. Presumably there's something to do in both of them ?

- (Related) regarding setting the starting position: The CNC machine has a nice extruded Al base I can easily attach stuff to. I'm assuming standard practice is to put a sacrificial piece of wood on the surface, then to attach the real workpiece to that sacrificial piece, to stop the router bit from hitting the base. What's the best practices for registering the starting position when one does this ? Do you manually jog the bit and just line up by eye ? Seems a bit touch-and-go...

I'm sure I'll have more questions as time goes by, but since the whole 'getting it accurately located' is not clear to me, I thought I'd start with that The Thing-o-matic (the 3d printer) aligns automatically using limit switches, and my other CNC machine (a dedicated PCB router) lines up with a camera and fiducial marks)...

Cheers
Simon