For the production of garden objects and street furniture made of various steel sheets, Thumm Technologies GmbH uses, among others, multi-rotary brushing machines from the Dutch manufacturer Timesavers.

Metalworking in a wide variety of forms – this is a brief description of the activities of the typical medium-sized company Thumm Technologies GmbH, D-72622 Nürtingen. Years ago, focusing on the development and production of cantilever stairs, the main components of which are solid turned parts, Dr.-Ing. Claus Thumm, the current managing partner, later shifted his focus to more promising businesses such as the contract manufacturing of rotary or cubic precision parts and sheet metal parts as well as the development and production of garden objects and street furniture made of metal. This segment now accounts for a good 2/3 of turnover, and is still growing, and employs the majority of the current workforce of around 100. Dr.-Ing. Claus Thumm explained: “We have been planning, designing and manufacturing the aforementioned metal garden objects and street furniture for more than 10 years. Our customers come from the gardening and landscaping sector, architectural firms and local authorities of all sizes and are very demanding in every respect. Above all in terms of design, optics and haptics as well as functionality and last but not least in terms of quality. Consequently, we not only offer all process steps from development, planning and design to production and assembly, but also rely consistently on modern machinery and well-trained, motivated personnel for 100% in-house production”. The range of products and services in the field of garden metal includes on the one hand the standard objects summarised in a catalogue such as fountain systems, planters, retaining walls, privacy screens, path boundaries, garden doors, letterboxes, fireplaces, benches, bicycle stands, wood storage and the like. On the other hand, we are specialised in highly individual solutions according to customer requirements. This requires a high degree of flexibility in both design and production with an annual growth rate of around 20%, naturally taking into account efficient and therefore economical production. Claus Thumm and his employees therefore go their own way here too, preferring to invest in additional production capacity in order to secure delivery and performance capacity, and in return foregoing the actually appropriate but unpopular shift operation.

Optimisation of technology and capacity instead of shift operation

This impressively illustrates the emphatic investment in rather “unproductive” activities such as deburring or surface grinding of laser-cut sheets. Whereas in the past several assistants and later a used belt grinder were used for manual deburring and grinding, which on the one hand required reworking and on the other hand repeatedly caused capacity bottlenecks, today the deburring and grinding of components made of steel, stainless steel and Corten sheets is largely done mechanically. Namely on the 42 series multi-rotary brushing machines from the globally active manufacturer Timesavers, NL-4460 Goes, which is one of the global market leaders with 70 years of experience and more than 50,000 broadband grinding and brushing machines spread around the globe. The first contact with Timesavers, represented in Germany and Switzerland by the long-standing partner Tritschler Maschinen & Werkzeuge, D- 79790 Küssaberg, was made on the occasion of a trade fair. Claus Thumm and his plant manager, Mark Schmid, had actually already decided on another machine supplier, but after intensive discussions with Jürgen Tritschler and Timesavers experts, they were convinced by the technology and performance of the dry-running multi-rotary brushing machine 42 series with working width 1000, as well as the support and service promise. The cooperation works so well that Thumm Technologies GmbH followed up the first machine purchased specifically for the processing of stainless steel sheet metal parts with another of the latest generation of the 42 series. This time with a working width of 1350 mm and universally designed for deburring and grinding small as well as large components made of various sheet metal types.

Deburr all sheets without conversion, round off edges, grind surfaces

The new, dry-operating multi-rotary brushing machine 42 series type 1350/1500 WRB for deburring, edge rounding and surface sanding features an abrasive belt unit and a rotating brush unit. For the sanding belt unit a frequency controlled main motor is installed for infinitely variable adjustment of the sanding belt speed. Furthermore, the machine has been extended by a throughput widening to facilitate workpiece handling and has been equipped with a 400 mm extension table and two rollers plus lateral stop as insertion support for sheet metal parts up to 1500 mm wide. The scope of supply also includes a set of sanding lamella brushes for edge rounding, five sanding belts with different grit sizes and finally a feed carpet cleaning brush. Timesavers’ Area Sales Manager, Ing. Ronald Raats, comments on the solution to the customer Thumm Technologies GmbH’s requirements: “The first machine delivered has an abrasive belt and two brushes, but the last one installed has an abrasive belt and eight brushes. This provides a high degree of flexibility for processing all small to very large sheet metal parts occurring at the customer’s premises. The conversion of the first machine from stainless steel to other types of sheet metal, which was often practiced in the past, is no longer necessary. In a highly flexible and partially automated operation, sheets in thicknesses from 1 to 20 mm are deburred and ground, and there are no longer any bottlenecks due to the increase in capacity with the second machine. In addition, dry processing completely eliminates wet grinding, which is problematic in terms of service and maintenance and requires a great deal of care.”

Quality improved, working conditions facilitated, motivation assured

With the success came the appetite, so that today at Thumm Technologies GmbH all sheets are ground through. Basically and beyond the aspects mentioned above, deburring of sheet metal parts is considered a technical necessity in order to optimise the subsequent processes such as coating, painting, galvanising, hot-dip galvanising. In addition, ground raw surfaces and rounded edges with a radius of 0.5 mm improve the haptics as well as the handling, the sheet metal parts and objects made from them look better and give an overall higher quality impression. Dr.-Ing Claus Thumm concluded: “With the semi-automated deburring and grinding as well as rounding of the edges, the process chain of our sheet metal parts production is now closed. Except for the loading and removal of the sheet metal parts, all functions are now automated, which also effectively relieves the employees. With our philosophy of on-schedule production from the material warehouse or a monthly material throughput of about 150 tons, this is already a word, because, for example, the manual and dirty deburring and grinding work as well as the handling of tools and sheet metal parts are very strenuous and time-consuming. With continuous deburring and grinding we literally kill two birds with one stone. The quality is continuously good and the employees are pleased with modern and up-to-date working conditions in addition to the work facilitation.”