Called “Cut Layer Additive”, this new additive approach produces large format, near-net-shape parts at incredibly low cost, using a lower cost additive machine. Unlike large format additive printers (like Thermwood’s LSAM), the new process makes large parts from a variety of materials that can’t be printed.
Cut Layer Additive parts are similar to large additively printed parts, in that they are essentially hollow structures made in layers. However, instead of printing the layers, they are instead cut from thick sheets.
How Does This Work?
To make this work, each layer is separated into two or more segments, which can then be rather efficiently nested on sheets of about any material that can be machined. Once cut out, the layer segments are re-connected using precision puzzle joints, machined into the segment ends. Dowel alignment holes, between layers, assure alignment, making assembly accurate and easy.
Overall, the process, both cut and assemble, takes (at most), the same amount of time and labor as needed to additively print the same part. With some material, it can be faster, sometimes a lot faster, plus, material cost can be almost shockingly low.
One interesting use of this process is to make the part from a porous material, machine it to final size and shape and then add a penetrating thermoset resin, such as epoxy, which soaks in and hardens, producing a large thermoset composite part. Thermwood used this process to produce a 12-foot-long aerospace tool for the incredibly low material cost of $2,000, in less time than it took to additively print the same part.
Cut Layer Additive can also make parts from metal as long as the metal can be CNC routed. To demonstrate this, Thermwood made a large aerospace trim fixture using aluminum. Its walls are only a bit over an inch thick, meaning it used less material than about any other way of making it.
Although the idea is simple, until now, doing it has been all but impossible.
Creating nested CNC programs to machine hundreds upon hundreds of individual layer-segments, each with a multitude of machining requirements, that must all precisely mesh together, is a truly monumental programming task. And all, just to make a single part.
Totally impractical with traditional programming. It just doesn’t make sense. Programming cost would overwhelm any possible savings.
The only way Cut Layer Additive works is if you don’t have to program it.
With Thermwood’s new system, there is no programming, at least in the usual sense.
Almost ten years ago, Thermwood developed a machine control that could do things, by itself, without a program. Today that capability is called “Machine Intelligence”.
To make Cut Layer Additive work, Thermwood taught it to make Cut Layer Additive parts. It doesn’t need a CNC program. You simply tell it what you want, and it makes it.
You tell it what you want in two steps, show it the shape, and tell it how you want it made.
Aerospace layup tool made using about $2,000 worth of material in less time than it took to additively print the same part.
CLA just needs a CAD file of the basic shape
You show it the shape by sending it a CAD file of the part you want, not a detail file, just the basic shape. It will assume that is the shape you want. Then you tell it how you want it made. Things like the material you want to use, how thick you want the walls, where you want to split layers for nesting, how much trim stock you want, things like that.
It’s easy enough, it can be done right at the machine, using a touch screen. Or it can be done in the office and sent to the machine for processing.
The machine then automatically creates the additive part and the layer segments needed to make it, nests them on your material and creates an internal multi tool program to cut it all out.
The entire process is rather straightforward and only requires a tiny fraction of the time and effort needed to program in the traditional manner.
Then, the machine cuts it out.
Aluminum aerospace trim fixture made using Cut Layer Additive. Although it looks solid, the surfaces are all only a bit over an inch thick which means it uses less material than about any other way of making it.
Step by Step Guidance
The intelligent machine offers step by step guidance to the operator throughout machining.
It also knows how to cut long thin layer-segments without them moving, even if they are made from a porous material that can’t be held by vacuum.
The machine prints information on each layer-segment, such as the layer it’s on and how it connects to other segments. This dramatically simplifies sorting and assembly. It also prints a QR Code on each layer-segment in case you ever need to re-cut that particular part.
Precision joints, dowel alignment between layers, and printed information makes assembly surprisingly quick and easy. There are several ways to attach layers together including bonding, screws, bolts and rivets, all supported by features the machine adds, when machining the layer-segments.
One of the first epoxy composite parts made during development of Cut Layer Additive used less than $400 worth of material.
Perfecting Machine Intelligence Since 2014
Thermwood sold its first machine that used machine intelligence in 2014, so has been working with this technology for almost a decade. We've been building Cut Layer type machines for almost fifty years. Thousands of them work reliably in factories around the world.
Cut Layer Additive combines these two proven technologies into something new and exciting. Such a simple idea, executed with cutting edge technology, could have a profound impact on a lot of areas.