Wood grows naturally to its final dimensions. There has been no way to produce objects from trees without subtraction of material. To use this material for additive manufacturing, it must be reduced to usable micro-layers which can be then laminated to re-grow it into shaped 3D objects. This is logical.
Veneer has often been laminated into blocks. Then it can be routed into objects via subtraction. The Concept of additive mfg. using veneer has very strictly guided options. In order to offer a concept, I am first trying to highlight some problems.
The idea of Laminated Objects is not an impossible process, but each component compounds problems that need expensive, complex solutions themselves. The need to simplify comes from understanding what the problems are…
WITH AN EXAMPLE of a window frame of 8′ x 4′: The bulk of the object is “air” or the empty space inside the solid portion of the frame. If built from sheets of veneer there would be need to “cut out” the inner portion [See sketch].
Problem 1 – waste of material + Problem 2 – handling of cut-out material waste + Problem 3 – management system for reuse / recycling. Problem 4 – the “pressing” of layers would result in bent corners due to high pressure requirements of the roller system. This gets worse with pressing over grooves. Problem 5 – With wood grain going all in one direction the result is bowing of the entire frame.
Problem no. 6 – “Additive Manufacturing” (AM) is the umbrella term under which 3D Printing is one type of process from many others. Without having any standard international definition, what is common to AM “wasted material is a small proportion of the produced volume”. With the example of the window frame, Laminated Object Making may not really be an additive process.
This system, is very similar to MCOR’s paper lamination. Speaking to Dr. McCormack in 2013 about the breath of their patent, I learnt that it could possibly prevent IP on similar processes using veneer. That itself could be Problem no. 7. Their website : http://mcortechnologies.com One of their videos: https://www.youtube.com/watch?v=GVzRyKxD6Zc
Our team at 4 AXYZ dealt with these problems in 2012 and cleaned up a process that also uses veneer. The key is how we minimize waste by using only “a slight excess” of the material required. We achieve the grain direction for visuals + cross-lamination to avoid bowing. The technology is simple because there is no usable waste. The slight excess use of material is to allow tolerance for 5-AXIS milling so the object is finished in an automated CNC process. With SAM (which is the patent-pending process of 4 AXZY), we believe we have simplified the total concept from CAD drawing files to finished object – fully automated.
This bring us to the Concept we are introducing. The SAM process is not restricted by sizes currently required in the building or construction industry, or for small decorative objects. The larger the machine bed, the larger the object we can produce. Our Italian machine manufacturer produces 16M long x 4M wide (52.5’ x 13.1’) machine beds for XLAM production. We can readily use that bed size and extend the size of the product which can be made using the SAM process.
The process uses wood veneer and the machine currently planned will use 1.0mm material. As we go forward, our hope is to increase variability from 0.3mm to 3.0mm thickness of raw material. The veneer is not wasted by cutting out of sheets. It is “drawn out” or extruded by the machine’s selection tool (hardware + software process) in the required width. It is then pressed in the cross directions and with overlaps so the object is strong with the final layers in the direction required for visual benefit. The machine is a two-part operation, including the 3D build and 5-AXES milling. This ensures fine finish of the built object to accuracy of 0.1mm.
The footstool shown, uses the SAM process. This is an early prototype produced in 2013. The leg-frames on both sides are single monolithic objects, as one-piece instead of four. The top is screwed on by a 16-year-old, so it requires no special talent for joinery, planing, and levelling since the process is entirely digital. 3 pieces constitute the stool, instead of 9.
For large scale wood products and building components, the SAM Process should be the concept of choice. More general information is available at http://www.4axyz.com