Introduction: 3D Foam Cut Ibex

Picture of 3D Foam Cut Ibex

I've recently seen some nice "3D" band saw projects like this reindeer at woodgears.ca.

Well... I have no bandsaw and still no christmas presents - but a CNC hot wire cutter and some leftover styrofoam...

So... lets make some large Ibex figures...

Step 1: Create a 3D Model

Picture of Create a 3D Model

If you google for "3d scroll saw pattern" you'll find tons of ready to cut templates.

But lets make a new one from scratch with a 3d CAD program - it is basically just 2 simple steps:

  1. Create a front sketch of the figure:
    • I think this kind of thing looks best if you keep it a bit abstract - don't try to add too many details.
    • Keep the cross sections thick. A real ibex has relatively thin legs - however a styrofoam figure with thin, long legs will easily break.
    • Once happy with the result extrude the sketch to create a 3d profile.
  2. Create a side sketch of the figure:
    • Basically the same as above - only this time you also need to think a bit about keeping things in proportion to the first sketch (so the head starts at about the same height in both sketches).
    • Then use this sketch to cut the first profile...

Now you can tweak the 2 sketches until you're finally happy with the result...

(You don't necessarily need a 3d CAD - 2d works fine as well but requires a bit more imagination...)

Step 2: Create a Drawing

Picture of Create a Drawing

Next we create a drawing from the 3d model:

  • The hot wire needs to cut below the legs in the second cut. To prevent the wire from scratching at the machine bed and possibly getting stuck I've extended the legs on the right view (first cut) a bit (see red arrow). This way I have some material left below the legs for the second cut (left view)
  • I've also deleted some unnecessary lines...

Step 3: Create the CNC Programs

Picture of Create the CNC Programs

I'm using my CAM Software Estlcam to create the 2 CNC programs for the cut:

  • Instead of a router bit I've just defined my wire as tool with the expected burn-off as tool diameter.
  • The first program is the view on the right:
    • Select "Part", then click on the right shape.
    • Set the start point of the cut with the "Start point" function close to the bottom of the left leg so the cut won't just start anywhere.
    • Set the origin to an appropriate position close to the left bottom.
    • Create the CNC Program.
  • And then the same for the view on the left...

Alternatively you can also just print the drawing and create wooden templates to use with a manual hot wire cutter.

Step 4: Cutting...

Picture of Cutting...
  • I've cut 3 blocks at once...
  • The material I've used is fine styrofoam. If you want something more durable try EPP.

Comments

Uncle Kudzu (author)2014-12-15

They look great! Good job!

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