"I am delighted that there is such a close relationship between your sales department and our designers." (Felix Kämpfer)
Christopher Reitz: Hello Felix, and a warm welcome to the REITZ Tec blog. It's lovely to have you with us. Today we're celebrating not just one, but two premières. One is that for once I'm actually the moderator, and the other is that this is the first episode in which we are in dialogue with a customer – and I can't wait to see how it goes.
Felix Kämpfer: Hello Christopher, neither can I, and of course many thanks for the invitation.
Christopher Reitz: My pleasure. I'm glad it has worked out. And before we now really get down to business, why don't you just tell us a little bit about yourself.
Felix Kämpfer: With pleasure! My name is Felix Kämpfer, and I've been the production manager at Stöckel Werkzeugmaschinen GmbH since 2018. Before that, I completed a degree in mechanical engineering at TU Darmstadt, and then worked for a while for a production company in the north of England. My main task was the optimisation of grinding processes. Which meant I got to know lots of grinding machines from the user's perspective.
Christopher Reitz: Would you tell us exactly what it is you at STÖCKEL do and what your core business is?
Felix Kämpfer: We're a family-run company from Herborn, employ about 35 people, and we manufacture high-precision grinding machines for surface and profile grinding. We've been active in this industry for about 40 years now. And among other things, we've been using granite as the construction material for our machines for almost 25 years now.
Christopher Reitz: That's right; I double-checked with my father, and he confirmed that the association between STÖCKEL and REITZ Natursteintechnik has existed for over 25 years now.
Felix Kämpfer: Exactly – since 1997.
Christopher Reitz: That's a long time.
Felix Kämpfer: It certainly is, and that's no bad thing.
Christopher Reitz: Can you tell me what kind of backgrounds your customers are from, just to give our audience an impression of where you are active?
Felix Kämpfer: Well, about half of our customers are traditionally from the world of tool and mould construction, so wherever high-precision tools need to be made. Others are in machine construction, gearbox construction, and also in the growing industry of medical technology.
Our speciality is tailor-made machines, and in particular machines that are precisely adapted to a customer's needs, from design to software.
Christopher Reitz: Your company has has all the departments from design to project management and acceptance, right?
Felix Kämpfer: Yes, that's right; it all happens at STÖCKEL in Herborn.
Christopher Reitz: Felix, now tell me – how does a complete project work? As you can probably imagine, as the manufacturer of granite I am extremely interested in how a complete process is planned, from start to finish.
Felix Kämpfer: Well, it mainly depends on the size of the machine. For smaller machines, at REITZ you often already have blocks in stock that we can then use. They are then made up as required. For larger machines, we usually phone you in advance to let you know. After decades of cooperation, this works smoothly because everyone involved on both sides is extremely familiar with the other's processes.
Christopher Reitz: I agree; continuity is extremely important here. So you always have the same contact person with us, and we can always rely on your sales department. We are usually informed in advance if you are in discussions with a customer, and if you're talking about larger machines. This in turn facilitates our planning, as we can pre-order blocks from our suppliers in advance or reserve our own stock goods for you.
Felix Kämpfer: It works wonderfully well. And when it comes to new developments, we're always happy to seek advice from the REITZ designers. Our last major project was for a machine bed measuring 13.5 metres in length. When you're talking about a machine of that kind of size, aspects such as stability and, of course, transportability are entirely different from those of a smaller one.
Christopher Reitz: That was also one of the biggest beds we've made so far. It was a very exciting project, I thought. Just planning the transportation for such a large machine bed was a challenge. So tell us: what was the project used for? What do you do with the machines, or what do your customers do with the machines?
Felix Kämpfer: This bed was for a machine with a grinding area of six metres in length and 800 millimetres in width. So the bed had to be just over twice the length because a grinding table was going to be moving back and forth on it. It was going to be used for the construction of particularly long pressing or bending tools – ideal for sheet metal production where very long sheets are processed.
And in addition, using granite enabled us to achieve a planarity of less than ten micrometres on an area of six metres. This exceptional length made this an exciting project, as our aim is to produce our beds uniformly. We know, though, that the steps in your processes are entirely different from ours. As far as I am aware, you first saw the bed, then mill it, sand it, and finally precision lap it by hand. The metal inserts are then fitted, since granite, which is a natural product, does not contain any threads.
Christopher Reitz: Very well observed!
Felix Kämpfer: Plus, of course, you can't just screw in threads. Instead, we glue metal inserts into the places where something needs to be screwed.
Christopher Reitz: That's right; you usually use Impala granite from South Africa for your projects. Then come the steps that you just described to us. The block is delivered to Asslar or to our extended workbenches, where it is then cut, milled, sanded and drilled. Then the metal inserts are glued into place. Manual hand lapping gives the block the high precision that corresponds to the customer's individual requirements. Tell us why you made the change to granite over 20 years ago.
Felix Kämpfer: Granite is known in technology for being a material with a high temperature stability. The linear expansion is about half that of steel or ferrous materials. This means that machines that work in a production environment are always subject to temperature fluctuations. So if I'm then working to a micrometre, I have to keep these fluctuations as low as possible. The customer then gets a better machining result with the machine across several processes.
Christopher Reitz: The thermal properties are our main advantage. We've already recorded an episode on this in our video and audio blog. Viewers are most welcome to listen to them. Do you think our granite has any other advantages?
Felix Kämpfer: Yes, and you've just mentioned them – the thermal properties. I've also mentioned the linear expansion as well, which is lower than that of steel, for example. But what is at least equally as important is the low thermal conductivity. This means that the machine overall responds far more slowly to temperature fluctuations. This results in much better process results over a long period of time. One big advantage for us as machine constructors is that I can freely design every granite block. This means that we are not bound to or have to follow existing models when we design machines. Nor do we have to go into series production for it to be worthwhile. Rather, we can always respond flexibly to customer requirements and manufacture individual items – we make a new start with every block.
Christopher Reitz: Yes, that's right; your machine beds are always adjusted individually. There's only ever a repeat effect with the quills, where we can almost speak of a standard product.
Felix Kämpfer: I am delighted that there is such a close relationship between your sales department and our designers.
Christopher Reitz: You've shared quite a bit of information with us. We'll be recording a second part on this subject in which you give us an insight into other projects. Many thanks in advance for that.
Felix Kämpfer:
My pleasure – until next time, and many thanks for your time.
Christopher Reitz: Thank you for listening and watching. See you next time. That'll be exciting as well.
