Automating your grinding process

What should you pay attention to when you want to automate your grinding process? There is a big difference between a welding process and a grinding process.

Automate your sharpening process: not if but when how and with whom.

The urgency of automation is clear in the manufacturing industry: the question facing almost the entire manufacturing industry is, "Where do I get the people who want to do the grinding work. Urgency is felt. The question is not so much whether we should automate but rather how and with whom. This article is a report of the robotization days, organized by Metaaltechniek and 3M, in cooperation with TFT and SHL. Characteristic of all these parties is their focus on the grinding process.

SHL - System Integrator with a focus on entrepreneurial security.

Purchasing a robot is a big investment, with equally big implications for finances, the entire production process and the skills of the workmen. SHL builds in many securities and supervises the entire process in order to meet expectations.

SHL starts with a visit to the shop floor. How do you work now, what needs to be processed, how large are the series or are they more single pieces, which steps need to be completed, what is the required final finish. But an inventory is also made of which existing production resources can function well in conjunction with the new machines.

In addition, a financial overview is created. Of course, it is possible to start with a basic concept and add modules later.

Proof of concept

After a positive initial survey, the feasibility study follows. Mainly the technique now receives attention. Points that SHL will always bring to attention are speed of work with very solid machines, preferably with very high rigidity to be able to do the work with low vibration. Any vibration compromises the result and operational reliability.

The main concerns for good results are minimizing vibration and sufficient force

Furthermore, clamping tools and spindles are discussed. Can they handle the forces released?

Auxiliary tools are not forgotten. Pressure and tolerance differences must be compensated. With cameras, checks are done or positions are monitored. With AI, it becomes possible to detect any possible error and fix it fully automatically. Ultrasonic sensors measure gaps or tolerances on typesetting or weld thicknesses to then adjust the grinding program.

The robot and everything involved, including all safety measures, are drawn in on a floor plan.Simulations are made that show the impact on the shop floor. In this way, bottlenecks and bottlenecks are identified and problems surrounding placement are avoided as much as possible. Then the output is also accurately determined, possibly by physical testing of sub-processes....

‍Tips& tricks from SHL

Offline programming has the advantage that the robot just keeps producing while you program the next product and start testing the operation virtually already. 
High-power grinding spindles will significantly increase the life of abrasives. Automation makes it possible to load the abrasive material very evenly. As a result, much smoother surfaces are obtained in a shorter time than by hand. It will also reduce the overall heat input.
Changing sanding belts manually remains the fastest. Optionally, with an extra arm on the robot, you can change the belt outside the cell. This way, the process can continue and the change can take place when the operator is ready.
Polishing is an operation where stability and power requirements are often underestimated. Polishing complex shapes with continuously equal parameters for top quality is not easy and requires a lot of knowledge.
Robotic grinding is not necessarily faster than manual grinding, but you can work 24/7 and no longer depend on availability and skill of grinders.

‍3M- Manufacturer of high-quality grinding materials: choose the right partners!

If you choose to implement a robot, gather the right partners together first. Explicit knowledge of hardware, software, attachments, machinery and abrasives is essential. Right now, there is no integrator that has all of this high-level expertise.

3M specifically set up a robotization division to gain and share knowledge with integrators such as SHL and TFT. They seem like simple details: which grinding belt do we put in? But with the wrong choice, an entire concept can fall apart. First, do thorough research on the strategy and use of an abrasive application. Possibilities and impossibilities can be tested in practice at the 3M CAT center in Neuss.

Opting for robotic grinding also affects the choice of abrasives to be used.

Lots of interest in the live demo: welding flat grinding and finishing of a stainless steel tray

Robotic grinding and abrasives

A major advantage of robotic grinding is the reproducible finish and consistent quality. Even if the starting material has large tolerances. To achieve the best results, it is necessary that the abrasives used also have these properties. An even wear pattern and a finish that remains constant until the end of the service life. 3M's Trizact and CubitronII products are therefore ideally suited for use on a robot. The same goes for Scotch Brite products such as Bristle Discs or unitized wheels.

Robotic grinding of stainless steel trays

‍TFT- Flexible and easy programming of a cobot

Flexibility in a production environment is indispensable, especially for smaller series. Thomas Sneijder demonstrates how easy it is to program a cobot, but also shows that grinding requires different conditions than welding. Delivering continuous equal force, while compensating for unevenness, demands a lot from a cobot. That is why TFT always chooses Doosan Cobots that are equipped with force sensors in all axes, and accurate to 0.2N.

Advantages cobot over robot or manual grinding

A cobot has a number of advantages over manual or robotic grinding. A cobot always delivers consistent performance, can be used for long periods of time and does not twist its arm for dirty work.

He works safely with a co-worker at the same workbench.

Compared to a robot, a cobot takes up less space, requires no additional safety measures and requires a lower investment. Programming a cobot is also easy to learn. However, a robot's payload is higher and a programmed robot works completely independently and may operate at higher speeds.

Tips & Tricks from TFT

When purchasing a cobot, ensure support in the company. Make two or three colleagues responsible.
Be well informed about standards, both in terms of programming, but also the so-called quick release systems of End-of-arm tools. This ensures easy expansion of capabilities in the future.
Fixturing of workpieces is easy by using welding tables with standard hole patterns.

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Closing of an informative and instructive day on automating the grinding process

"Together towards the perfect finish" is our slogan. It cannot be a coincidence that all three of our partners' presentations also featured this slogan. Choosing the right partners is essential for a successful end result. The enthusiasm of our customers was great. The Dutch manufacturing industry is making strides in automation, we will have to. But how fascinating and educational it is to work with it.