3D Advance Metrology by means of 3D Atomic Force Microscopy

We developed a new 3D-AFM technique that enables imaging of high aspect ratio trenches. By measuring both lateral and vertical forces on a cantilever tip, a subharmonic mode based on the attractive tip-sample forces becomes feasible. This enables the measurement of true 3D information of samples without causing damage. This is especially...

TESLA-C Optical Bench

To accommodate such a massive satellite constellation with OCT’s, the following key drivers are identified for the space terminals: - Low Size, Weight and Power (SWaP): One of the key advantages of using optical communication wavelengths over RF wavelength is that it allows for highly compact and low power OCT’s. To fully realize this potential,...

Compact spectrometers for earth observation

Driven by technology developments triggering end user’s attention, the market for nano-and micro satellites is developing rapidly. At present there is a strong focus on 2D imaging of the Earth’s surface, with limited possibilities to obtain high resolution spectral information. More demanding applications, such as monitoring trace gases,...

High-grade, compact spectrometers for Earth observation from SmallSats

The market for nano-and microsatellites is developing rapidly. There is a strong focus on 2D imaging of the Earth's surface, with limited possibilities to obtain spectral information. More demanding applications, such as monitoring trace gases, aerosols or water quality still require advanced imaging instruments, which are large, heavy and...

Target relative navigation results from hardware-in-the-loop tests using the sinplex navigation system

The goal of the SINPLEX project is to develop an innovative solution to significantly reduce the mass of the navigation subsystem for exploration missions which include landing and/or rendezvous and capture phases. The system mass is reduced while still maintaining good navigation performance as compared to a conventional modular system. This is...

Sinplex: A small integrated navigation system for planetary exploration

SINPLEX is a sensor suite for spacecraft navigation purposes. This paper addresses the current status of the SINPLEX prototype and the systems engineering process that has led to this status. The SINPLEX prototype is currently being integrated with the aim to demonstrate Technology Readiness Level 4, i.e. a component and/or breadboard validation...

Design of micro square endmills for hard milling applications

In experiments of machining hardened tool steels (such as AISI H11, H13, and D2, up to 56 HRC) by commercial Ø 0.5 mm square endmills, it is observed that the tested micro endmills showed severe wear at an early stage of the process due to chipping off around cutting edge corners, resulting in unsatisfactory tool life and product appearance ...

Verspanen van moeilijk bewerkbare materialen

Hier vindt u het boek over het verspanen van moeilijk bewerkbare materialen. Het is het resultaat van het TNO kennisoverdrachtproject “Verspanen van moeilijk bewerkbare materialen” Het bevat zowel achtergrondkennis als praktisch toepasbare richtlijnen en gegevens. Het is een introductie in dit onderwerp en kan ook gebruikt worden als naslagwerk....

Automatic in-process chatter avoidance in the high-speed milling process

High-speed milling is often used in industry to maximize productivity of the manufacturing of high-technology components, such as aeronautical components, mold, and dies. The occurrence of chatter highly limits the efficiency and accuracy of high-speed milling operations. In this paper, two control strategies are presented that guarantee a...

Chatter control in the high-speed milling process using μ-synthesis

Chatter is an instability phenomenon in machining processes which limits productivity and results in inferior workpiece quality, noise and rapid tool wear. The increasing demand for productivity in the manufacturing community motivates the development of an active control strategy to shape the chatter stability boundary of manufacturing...

Development of an operations evaluation system for sinking EDM

This paper describes the development and validation of an operations evaluation system for sinking EDM operations. Based on a given workpiece geometry (e.g. mould), regions to be EDM'ed are automatically indentified. For a given electrode configuration, consisting of one or more regions, EDM machining times are calculated, making a proper...

Micromilling of thin ribs with high aspect ratios

Micro features with high aspect ratios are one of the commonly encountered geometries found in micro products. In the literature, these structures are often used in demonstrator products machined by a micromilling process. In this paper, the challenges in micromilling thin ribs with high aspect ratios have been studied. Due to the scaling effect...

A study of factors affecting the performance of micro square endmills in milling of hardened tool steels

Proper setting of cutting conditions is critical for the performance of micro endmills in micro milling of hardened tool steels. In this paper, the influence of the cutting parameters on the wear behaviour of micro square endmills is presented. The selected parameters are cutting speed, depth of cut, and feed per tooth; Central Composite...

Experimental study of the surface roughness of hardened tool steel Böhler W300 milled by micro square endmills

Surface roughness is a key parameter in evaluation of engineering surface in macro scale; in case of micromilling, it is of even greater importance because the magnitude of the roughness can be comparable with the workpiece tolerance, and will have a direct impact on the quality of the microproducts. This paper presents the preliminary results...

Tool Neck Geometry Design to Improve Stiffness of Micro Endmills

Due to the scaling effect, micro endmills have low stiffness in nature, which will result in lose of form accuracy in workpiece and vibration of micro tools during micromilling process. Through analytical modeling, it is found that the neck geometry of the micro endmill has a big influence on the tool stiffness; therefore it is important to...

Experimental validation of micro endmill design for hard milling application

Abstract: In experimental investigations of micro milling of hardened tool steel SAE H11, with a hardness of 56 HRC, with commercially available micro square endmills of Ø 0.5mm, it was observed that the endmills suffered from severe tool wear/failure. Because of these problems, the quality of the machined workpiece was not satisfying, in terms...

Improvement of micro endmill geometry for micro hard milling application

One of the applications of the micromilling technology is to machine micro features on moulds by direct machining of hardened tool steels. However at this moment, this process is not industrial applicable because of the encountered problems, such as the big tool deflection, severe tool wear, and pre-mature tool breakage. A detailed examination...

Improved method for the cutting coefficients calculation in micromilling force modeling

This paper discusses the influence of runout on the calculation of the coefficients of mechanistic force models in micromilling. A runout mode is used to study the change of chip thickness, tool angles, and immersion period of two cutting edges of micro endmills due to runout. A new method to find the cutting coefficients was proposed based on...