By: David G. – President
Why would we say that 3D Printing (Additive Manufacturing) is a game changer for just-in-time manufacturing when a Mill or Lathe, which I will refer to as CNC even though additive technologies are also Computer Numerically Controlled, can cut all sorts of materials and can be a very versatile asset to an assembly line? The first and probably most critical reason stems from the base definition of just-in time which we laid out in the Intro to “JIT” Additive Manufacturing. Which said that it “is a strategy that strives to improve a business (any business, not just manufacturing) return on investment by reducing in-process inventory and associated carrying costs. This is done by attaining the perfect quantity of raw material and producing the right quantities of product, in the right place, at the right time.” If the just-in-time strategy is based on lowering this inventory and producing as close to the order date as possible, then how can a process that has to stock different size materials, or different materials for that matter, and rely on material providers getting materials into these specified sizes be considered the best for just-in-time? Whether the raw material is in a block form or any other net shape, from my experience, there are typically still a lot of machining processes that need to be done by a vendor to get the part into its final assembly ready state. Not to mention that this raw material usually can’t easily be used for a completely different product without a fairly lengthy reprocessing/reshaping procedure.
As a vendor, we adopted the mindset that additive manufacturing technologies were going to be more versatile for us than CNC equipment early on. By doing this we have seen a tremendous efficiency increase in the number of customers we can service all at the same time, sometimes all on the same machine, something that is never really seen on a CNC machine. We are able to do this based on three other fundamental reasons why Additive Manufacturing technologies are changing the way we think of Just-In-Time. These include not having “tool paths” that we have to worry about crashing into other parts, the machine time is not typically increased linear when adding more parts onto a single build and we also have the capabilities on equipment like the Objet Connex to produce multiple material parts on the same build platform, something a CNC machine definitely can’t do.
Some CNC machines allow for quick replacement of the work piece via rotary or slide tables like that of the HAAS APC unit below.
But as you can see from the description, it still only allows for one part to be worked on and loaded at any single time. With Additive Manufacturing Equipment, multiple parts can be loaded all at the same time. The number of parts can differ, some machines are only efficient filling up “one layer” or in other terms not stacking parts on top of another, but still are able to fill up the full X and Y axis of the build envelope. Other technologies such as Selective Laser Sintering (SLS) can efficiently “nest” parts overlapping each other as show below which can both increase the efficiency of each pass of the laser by allowing it to sinter multiple parts, but also allows the equipment to run in more of a Lights Out environment on more customer projects, a vendors dream manufacturing environment.
In being able to increase the efficiency of the Additive Manufacturing “solidification method”, i.e. the laser or print head etc. the effective time it takes to produce one part exponentially goes down, helping to get the product out the door Just-in-Time.
As CNC equipment continues to improve and become more efficient, the ability to “nest” parts becomes less of a competitive part of redefining Just-In-Time, but something that CNC machines will most likely never be able to compete with Additive Technologies on is the Material Inventory side. All additive technologies work with base materials that can be used to create any shape, size or complexity part that the user wants. It allows a vendor to stock much less material and not have to worry about getting a block of material at the minimal size just-in-time for producing the specified part. Some Additive Technologies even allow for the recycling of unused material right back into the machine, chocking one more win up for Additive Manufacturing in the battle for Just-In-Time.
A great successful example of this ability to better control and use inventory more efficiently is the Objet Connex technology. When first released in 2008, the technology was already revolutionary by being able to produce more material properties on separate parts than originated in the two cartridges loaded in the machine such as a shore 85 and 90 A from a shore 60 A and 83 D base material. But then just by tweaking the way in which material was being deposited, a user can now produce up to 16 different materials with different properties just by using a shore 27 A and 83 D base material, seen below.
One of these materials being a shore 60 A material that is stronger than the original 60 A base material, still available for single material machines. This has allowed vendors such as us to completely remove the 60 A material from our inventory while still producing parts with improved material characteristics. The true epitome of reducing inventory while increasing production and meeting the base definition of Just-In-Time, all at the same time.
Thanks for reading and stay tuned for our next insight on how Additive Manufacturing is changing Just-In-Time from the Manufacturers’ (O.E.M.) perspective.