In today’s machine construction it’s all about achieving consistent high velocity and the highest accuracy beyond the machine’s life expectancy with minimal impact in regard to vibration and power consumption. RAMPF Machine Systems GmbH & Co. KG have, together with Essemtec AG, developed for this machine class a unique mineral casting frame for the SMD P&P assembler Fox and the dispenser Spider.
Most of the assembly machines currently in production in the low speed sector (> 15’000 cph) were developed more than seven years ago. These machines can contain pre-2007 computer systems, one-sided spindle drive with shaft joints and welded machine frames.
On the other side, there are the requirements of the today’s users to take into consideration. These expectations are being driven by the prototype production and engineering sectors: The life span of their machines must be at least 12-15 years and the machines must be able to assemble the smallest and most complex components with highest accuracy for the full life of the equipment. However, welded machine frames have a habit of warping under high strain, such as that generated by the start and stop ramps of the fast X/Y axis systems. Vibrations can not be released, therefore inaccuracies within the process, a high level of noise emission and increased attrition of frame and components may occur. Subsequently, after a few years the original manufacturers’ specified and guaranteed accuracy of 30 – 50µ in the +/- sigma zone is no longer achievable.
Therefore, instead of the investment calculation being realised over a life span of 12+ years, such a machine may need to be replaced after just half of its life expectancy and so an unplanned investment is enforced. Here RAMPF can supply a solution. RAMPF has developed an alternative casting frame, which guarantees highest accuracy combined with highest vibration dampening even after years and years in use. The material used, EPUMENT mineral cast, is used within various industries.
Specially selected minerals and a high-quality binding agent, based on epoxy resin, pave the way for machine components with impressive properties, a wide variety of design options and tangible economic benefits. The ingredients of EPUMENT mineral casting get dosed, mixed and poured into forms, they are then condensed; afterwards they harden in the mould. Each construction material has its own specific configuration rules. Constructing machine casting frames using mineral cast, some material specific principles need to be considered, for example drafts or minimum wall thicknesses.
Mineral castings are isotropic, homogeneous materials that follow Hooke’s law and are analysable with linear elastic FEM (Finite Element Analyse) calculations. That is why one can find an optimal texture and basic structure, even for assemblers with linear drives like FOX 1, FOX 2 and SPIDER.
Of special interest for machine engineering industry is thermal inactivity and excellent vibration dampening. Is a Euro coin placed upright on a mineral casting frame, this coin will not fall down while the machine is in production mode. This illustrates that vibrations are just slightly transferred to the coin.
A good production energy balance (without external heat supply), problem-free disposal at waste material sites as well as the ease of recycling the material supports the advantages of mineral cast from an ecological point of view too.
Further plus factors are:
• no electrical conducting
• no burrs
• Superior damping compared to metal materials improves the dynamic stability of the machine bed structure
• excellent vibration-reducing properties
You can see more about mineral casts here:
Essemtec AG decided to apply this technology to Fox 1, Fox 2 and the Spider. Using EPUMENT mineral casting frames, Essemtec is in the envious position of being able to offer their customers “state of the art” machine technology including best performance characteristics. Such characteristics are for example: Process stability, increased accuracy, best thermal properties and ideal vibration dampening at increased dynamics.
The RAMPF group stand for “Engineering and Chemical Solutions” and caters to the economic and ecological needs of industry. RAMPF secures its presence on the market with more than 700 employees and six companies. RAMPF thinks globally and acts locally, with production facilities strategically located in Germany, the USA, Canada, Japan and China. Their worldwide network of partners provides contract manufacturing and prototyping, has vast material storage capacities, and ensures first-class on-site consulting and a comprehensive service. No matter where you are in the world, you can be sure that when it’s labelled RAMPF, it is RAMPF. (http://www.rampf-group.com/)