By David Alatorre, CTO, Rivelin Robotics
Using metallic additive manufacturing has revolutionized the manufacturing trade, permitting for the creation of advanced and complicated components in a sooner and cheaper method.
Nonetheless, important publish processing of those components introduces time and monetary constraints to the general cost-per-part that may negate the advantages of additive manufacturing altogether. Assist removing is the important first step of publish processing metallic additive manufacturing components, and it’s a difficult one.
Right this moment, helps are nonetheless important for half constancy in the course of the manufacturing course of, however they have to be eliminated to attain the required completed product with the meant form, options and tolerances.
Whereas handbook help removing continues to be the established order for a lot of functions of metallic additive manufacturing, this text will deal with the transition to automated help removing (and ending) options and take into account the benefits and drawbacks of utilizing Laptop Numerical Management (CNC) methods versus the flexibility and reliability of robots.
To help or to not help
There may be an argument that the help removing conundrum in additive manufacturing will ultimately be resolved by so-called support-free printing. After all, this might be the final word purpose, permitting full design freedom with optimised useful resource effectivity, whereby uncooked supplies and vitality are solely getting used to make the ultimate half and never the helps.
Sadly, the additive manufacturing sector is just not there but, and whereas helps are being minimised by design, they’re nonetheless — and shall be for the foreseeable future – a necessity.
Minimising the quantity of fabric and vitality used for helps is the suitable factor to do in nearly each scenario, however it could possibly additionally compromise design freedom and have a detrimental affect on the specified performance of the end-use half, which can, for instance, have to be designed with crammed cavities or overhangs resulting in lack of light-weighting.
Generative designs can also be unnecessarily constrained to get the angles wanted for lowered helps.
A give attention to help discount may have an effect on course of effectivity. For instance, lengthy components could should be in-built a particular orientation and due to this fact take up extra of the construct plate, and stacked builds could develop into impractical due to the interconnecting help buildings.
Briefly, whereas we must always at all times attempt for much less helps, they’re presently nonetheless a essential instrument for many advanced additive manufacturing functions.
Guide publish processing
Shockingly, handbook help removing stays the method of alternative for almost all of additive manufacturing customers in the present day. It requires extremely educated technicians to take away helps with all method of conventional hand instruments.
Dremels are available in helpful too. It’s tried and examined however requires talent, problem-solving and creativity. It may be nicely suited to excessive combine, low quantity manufacturing environments.
Nonetheless, handbook help removing can be very time-consuming, labour-intensive, messy, with poisonous mud requiring PPE or shielded environments. Threat of powder ignition and explosion, and repetitive pressure accidents are widespread issues.
As well as, it’s not precisely repeatable with variability from individual to individual and even from shift to shift inflicting high quality management issues and will increase in scrap fee. It is usually tough to scale if the demand for additive manufacturing components begins to extend considerably.
Automation, automation, automation
There was some progress with options for automating the publish processing of metallic additive manufacturing components. The commonest has been the utilisation of CNC milling machines, a confirmed know-how for a wide range of manufacturing functions, together with a hybrid strategy to additive manufacturing.
They’re undeniably correct and repeatable. Nonetheless, simply because one thing is widespread and has a very good monitor report in some areas, it doesn’t essentially imply that it’s at all times the very best resolution.
CNC can work nicely if the half in query has tightly toleranced options, and the place flatness, circularity, concentricity, or dimensions should be inside just a few microns.
It is usually the popular know-how for help removing in giant batch builds the place geometries are easy or lend themselves to simple fixturing in solely a few orientations.
Equally, it may be a very good match for prints the place platform removing with a CNC EDM takes care of nearly all of helps.
Nonetheless, CNC machines should not a very good resolution for thin-walled parts, space-saving stacked builds, and components with lattice buildings or breakaway helps. It is usually truthful to say that CNC programmers don’t like one-off generatively-designed natural shapes with compound curves.
This begins to make clear and strengthen the argument in opposition to CNC for help removing within the additive manufacturing ecosystem.
One of many major drivers of additive manufacturing is the pliability of design that enables customers to iterate, customise, and improve parts from one batch to the following. Which means it’s uncommon for firms utilizing additive manufacturing for manufacturing to spend money on inflexible industrial automation.
Any iteration, any change to the design would imply a brand new CNC trajectory for a brand new instrument path and are available at a excessive value. additive manufacturing wants this design flexibility to be carried to each step of the manufacturing course of chain.
The issue is analogous for tooling and fixturing. The sorts of high-precision fixtures required for inflexible industrial automation simply don’t make sense except you are ready to decide to a design long run.
After which there’s the issue of batch-to-batch variability. Even when you did have an ideal fixture and an ideal instrument path, counting on a superbly predictable help floor straight from the printer is probably not the very best thought.
It’s because it’s anticipated that additive manufacturing helps deflect so AM components don’t should. AM helps are made skinny to maximise the usage of powder inventory. Skinny connections are made to the part to minimise floor witnesses and make it simple to interrupt away the scaffolding.
Materials composition is even modified between batches generally, all of which implies helps could look and behave very in another way from one batch to the following.
Robots to the rescue
So, additive manufacturing wants automation that may adapt to variability, particularly for help and witness removing. And this problem has been solved by the usage of refined software program and synthetic intelligence methods to assist generate toolpaths and robotic motions with out mobilising a whole systems-engineering group.
This then permits for fast iteration in addition to automation of small batches.
3D scanning can be utilized to find components as an alternative of high-precision fixtures, which implies desktop FDM printers can be utilized to make plastic fixtures rapidly with out worrying about accuracy or adjustments to the design.
As well as, pressure sensors can be utilized to really feel the floor and adapt the machining accordingly, or to spend extra time on excessive spots till the ultimate form is reached, or to shine to a constant end
One enormous benefit is that any instrument can be utilized for help removing and ending. Whether it is already identified what instruments work nicely with the supplies or the varieties of helps printed, the identical precise instruments might be connected to a robotic to automate with extra confidence.
With in the present day’s know-how, the steps so as to add a brand new customized instrument are principally like including a brand new kind of endmill to a CNC machine, and doesn’t require a system integrator that prices by the hour.
Rivelin Robotics, which specialises in metallic additive manufacturing post-processing, already has merchandise that do that. The corporate specializes within the improvement and set up of robots for a variety of AM publish processing functions.
Within the context of eradicating helps from metallic additively manufactured components, Rivelin Robotics affords superior robotic options which are particularly designed to carry out this process reliably and precisely.
The corporate’s robots present a spread of advantages over conventional CNC machines, similar to improved velocity, accuracy, and repeatability when utilized to help removing and ending. They’re additionally extremely versatile, which permits them to be simply tailored to completely different functions and processes.
Rivelin Robotics’ robots are additionally designed with security in thoughts, with protecting casing and security options that scale back the chance of accidents and accidents.
Furthermore, energy and coolant necessities are far decrease than is the case with CNC machines, which helps enhance useful resource effectivity and vitality effectivity whereas on the similar time decreasing waste.
To summarise, robots are rising as a superior resolution in contrast with CNC machines for the automated removing of helps from metallic additive manufacturing components as a result of their velocity, effectivity, flexibility, accuracy, repeatability, security, cost-effectiveness, and sustainability.
Using robots on this course of not solely ends in a greater completed product, but additionally gives a safer, extra sustainable and cheaper end-to finish manufacturing course of.