We have a couple of projects running in bone just now. Preparing
tutorials for Fourth Axis clients, my team is showing how to fix
bandsaw-cut bone slices to easily-grippable softwood sacrificial
bases using PVA woodwork glue, for both XYZ and rotary milling. XYZ
work includes pendants (mostly flat backed but some 2-sided flip
work). Rotary work includes small statuettes (hollow center to avoid
the marrow space of the bone) and tubular work.
Bone slices bonded to softwood with PVA woodwork glue for gripping
them outside the bone volume, can be released by later soaking in
Bone behaves amazingly like Delrin plastic during milling and the
parameters you would set for Delrin work fine with bone. It is very
important to take dust-collecting measures, because of the risk of
bone-carried organisms entering the respiratory system. We are using
full-time HEPA-filtered vacuums and properly enclosed machines. High
spindle speed (up to 20,000 rpm) with modest feedrates can produce a
polished finish straight off the mill. We are using fine ball-nose
endmills in Roland MDX-15 and MDX-20, high-speed third-party
spindles (Proxxon 28485) and Fourth Axis Model 15 or Model 20 rotary
One of our clients, who has traditionally used Delrin to make
ivoryesque statues by CAD/CAM/CNC, is amazed at the quality he can
obtain from bones sourced as pet-food! Large bones (cow hips etc) can
be band-sawed into thin slices of quite large area, while the longer
bones such as femurs provide a source of tubular stock for cylinder
In our gallery http://www.fourth-axis.com/gallery/ you can see a
sample of the work of Fourth Axis client Arnand Loupier. Arnand is
currently rotary milling a Chinese chicken/chrysanthemum work of art,
obtained from an antique wood-carved temple door panel, in cow-bone.
Arnand previously provided us with 3D scanned XYZ files which we
FLOWed in Rhino for him, creating cylinder geometry for toolpath from
Modela Player 4. The waxes (at several scales) are scheduled to be
cast from inoxidable bronze.
Bone is a wonderful resource. It can be antiqued, sealed, left
natural. There is a well-managed supply at the butcher shop.