The early conceptual design phase often focuses on functional requirements, with limited consideration of the manufacturing processes needed to turn design engineers' conceptual models into physical products. Increasingly, design and manufacturing engineers no longer work in physical proximity, which has slowed the feedback cycle and increased product lead-time. Design for manufacturability (DFM) techniques have been adopted to overcome this problem and are critical for faster convergence to a manufacturable design. DFM tools give feedback in textual and graphical modalities. However, since information modality may affect interpretability, empirical evidence is needed to understand how manufacturability feedback modalities affect design engineers' work. A user study evaluated how novice design engineers' design performance, workload, confidence, and feedback usability were affected by textual, two-dimensional (2D), and three-dimensional (3D) feedback modalities. Results showed that graphical feedback significantly improved performance and reduced mental workload compared to textual and no feedback. Differences between 3D and 2D feedback were mixed. Three-dimensional was generally better on average, but not significantly so. However, the usability of 3D was significantly higher than 2D. Conversely, providing feedback in textual modality was often no better than not providing feedback. The study will benefit manufacturing industries by demonstrating that early 3D manufacturability feedback improves novice design engineers' performance with less mental workload and streamlines the design process resulting in cost-saving and reduction of product lead-time.

The invention relates to a system for drilling holes and for placing rock bolts, especially in underground mining and tunnel construction, comprising at least one rock drilling machine (2) that can be displaced by a limited displacement path on a mount (1) the front of which is provided with supporting claws (3) for supporting the mount (1) on the rock, the rock drilling machine (2) having a flushing head (4) that can be alternatively supplied with flushing water for drilling or with high-pressure water for bolt placement. In order to bridge the dead space towards the rock when using such a system for bolt placement, the flushing head (4), in the direction of the rock, is at least sufficiently long for its front end to reach the supporting plane of the supporting claws (3) of the mount (1) when the rock drilling machine (2) is at the front end of the displacement path.

The invention relates to a system for drilling holes for rock bolts or blastholes and for placing rock bolts (4), especially in underground mining and tunnel construction, comprising at least one rock drilling machine (2) that can be displaced on a mount towards the rock, the front of said mount having a rod guidance structure (6), for drilling a drill string (3) into the rock and for the subsequent placement of a rock bolt (4) in the drill hole thus produced. The tool fitting (5) of the rock drilling machine (2) has a fitting opening suitable for receiving both drill strings (3) and rock bolts (4). The mount (1) is provided with grippers (11, 12) that position the drill strings (3) or the rock bolts (4) in the drill axis (7), the grippers being mounted on the mount (1) so that they can be laterally retracted from the drill axis. In order to allow further mechanized operations, separate grippers (11 and 12) are provided for the drill strings (3) and the rock bolts (4), respectively. These grippers are mounted on the mount (1) on opposite sides and can be swiveled out to opposite sides and allow the rock drilling machine (2) to be displaced during drilling or during bolt placement.

An apparatus for fabric windings includes a rotating mandrel and a plurality of fabric supply rolls. The rotating mandrel pulls sheets of continuous fabric from the plurality of fabric supply rolls. The rotating mandrel includes a main body having an inner end and an outer end, the outer end having a diameter greater than a diameter of the inner end. The main body of the mandrel is generally cylindrical with two truncated surfaces opposite one another.