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 Eucalypt milling with circular breakdown, Woodmizer and breastbench

The breakdown circular saw halves the log...
...then quarters it

The log is quartered through the pith using a circular breakdown saw. This releases the tension as curve on both faces of each quarter. Because the maximum tension is being released with these cuts, some surface splitting can occur ahead of the saw on these faces (see below).

Logs which are too big
A few inches to go... for the saw are still cut and then finished with a chainsaw.

The quarters are then transferred to a woodmizer for slabbing.

Two quarters are slabbed at once on the woodmizer for efficiency. The thin kerf allows for good sawn recoveries and accurate cutting. The band should be changed before it is worn and deviates.

Because the bottom faces on these quarters may have some surface splitting, the bottom slabs on the quarters are oversized.

All of the edging is done on the breast bench. Most slabs only require edging, but the oversized slabs also require one face cut to remove the split surface.

Although three pieces of equipment are used, this system produces good sawn recoveries and is both cost-efficient and productive.

Quarters waiting to be slabbed on the woodmizer. Note they are cut exactly through the pith (not necessarily the centre).
These breakdown cuts can split ahead of the saw. These faces are resawn later on the breast bench.
With smaller diameter logs these two 56mm slabs are cut. With larger diameter logs two 28mm slabs are cut which will become 83mm x 28mm boards.
The rest are cut at 28mm for edging on the breast bench to 110, 136 and 162mm widths. The two bottom slabs are thicker (32mm) so that 4mm can be removed from the split bottom face later on the breast bench. These cuts are referenced from the bottom, also allowing for the 3mm kerf.
The oversized slab (there are four of these per log). The first edge is cut freestyle, removing inner wood.
The fence is used to dimension the width.
The face is then cut to 28mm, removing the surface splitting.

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