A shamrock basically consists out of four hearts that meat in the middle. So this is how we create it. We take a heart from the shape-menu, copy this three times, rotate the copies by 90°, 180° and 270°, move them in a way that they form the outer part of a shamrock. Add a circle in the middle and use the unite function to join them. (see images). Pay attention that the result has the same dimensions in x and y.

Now we have the basic form – a single shamrock.

Now we make scaled copies of the shamrock. We place the original one (the center piece) at x=0mm and y=0mm. Now we copy this, scale it 4mm bigger in x and y and move it to x=-2mm and y=-2mm. This way it is exactly centered again.

Between the original and the second shamrock is the inner gap that we see in the design. Now let’s copy this shamrock again, scale the new one that it is 8mm bigger in x and y and move it to x=-6mm and y=-6mm.

Of course you could use other sizes here. Just scale it and move it by half the size difference.

You can of course vary the sizes here. You have to play a little bit with the initial geometry and the sizes of the gaps to ensure that the material is wide enough at all places to have it cut later.

Select the two outermost shamrocks and choose Combine->Subtract at overlap. Now select this geometry and the next shamrock and select Combine->Unite. Continue to do so – always one Subtract at overlap, one Unite until you reach the innermost shamrock.

Your geometry looks unchanged after this step. Nevertheless, for the next step it is important to do this,.

In order to stabilize our creation we need a pin. Draw a rectangle through one axis of the geometry. Unite this with the geometry.

Use the provided parameters or adjust them to the wood you use. Pay attention, that the gaps are difficult to remove and that you might destroy your shamrock decoration if you do not act carefully. I would also recommend to paint the decoration before you remove it from the machine. This way everything is stabilized by the surroundings and the material in the gaps. I used a sponge for painting which gave a nice color.