Prusa Face Mask Headband

As part of the industry’s response to the Covid pandemic, along with many other small businesses and individuals, Charlie Victor produced hundreds of face mask headbands, from files uploaded by 3D printer manufacturer Prusa, for health workers in the early months of the crisis until more sustainable supply chains could be established.

The process proved itself to be ideal for collective mass-production and enabled the 3D printing community to participate in an initiative to protect key workers. 3D printing has provided a vital link between digital physical models, quickly and accurately translating from the screen to a part you can hold in your hands, offer up to check the fit of parts, or even test mechanical performance.

Tube Train Floor Section Test Pieces

Background

During floor material removal, some units were found to have small areas of corrosion and pitting of the extruded aluminium floor planks and a means of addressing the issue was sought. One proposal was to machine small, stepped holes in the floor and bond patches in place.

Brief

In order to test whether the patches could withstand the loading requirements, equivalent to 90kg/cm2, sections of the floor plank extrusion were required. As no leftover extrusions from manufacturing were available CV was approached to provide equivalent sample pieces. The specification required that the samples matched the train floor in its current condition as closely as possible, the rolling stock being 30 years old.

Solution

The flooring section was reverse-engineered in SolidWorks from the original manufacturer’s drawings and 200mm long sections were wire-eroded from solid 6020 grade aluminium to replicate the age-hardened condition of the train floor.

Several different hole profiles were trialled to cover all the possible patch requirements and a number of prototype patches were machined.

Tube Train Camera Installation

Background

As part of an upgrade programme to underground trains, CCTV cameras are being fitted to ceiling panels in passenger saloons. New installation brackets and wiring management needs to be designed.

Brief

As the cameras will be mounted to hinged ceiling panels that will be opened for maintenance, the wiring will need to be managed in such a way to ensure that it does not buckle out of shape and become trapped during the opening and closing of the ceiling panels.

Solution

Through a combination of 3D scanning and reverse engineering from the original manufacturers drawings an accurate SolidWorks model of the saloon roof structure and hinged ceiling panel was produced, including other equipment and wiring that exist in the location area. Using 3D printers and modelling board a physical model was made onto which were fitted printed models of brackets of various designs and the behaviour of the conduit, in which the wires were to run, was observed during opening and closing of the panel. By this practical means we were able to define and prove the optimum design and positioning of the camera bracket and camera lead conduit.

Tube Train Floor Repair Equipment

Background

During floor material removal, some units were found to have small areas of corrosion and pitting of the extruded aluminium floor planks and a means of addressing the issue was sought. One proposal was to machine small, stepped holes in the floor and bond patches in place.

Brief

To devise a means of milling out prescribed hole profiles in the car subfloor while accurately controlling the depth of cut. Equipment must be portable and able to be positions such that any area of corrosion might be effectively dealt with and be capable of being secured to the floor structure by a non-invasive means.

Solution

CV designed a sliding frame system with a series of templates of varying sizes and thicknesses which enabled a router to be used to cut out the corroded area while maintaining material thickness in the shoulder around the hole. The main carrier frame was secured to the ‘T’ sections in the subfloor by means of sliding jaws that are secured by tightening the hand screws. The template carrier frame is then moved to the correct position over the effected area of floor, positioned by means of a clear ‘target finder’ template, and then tightened in place. By selecting the range of templates appropriate for the size of the corrosion and by following the templates sequentially, a clean and precise hole is achieved, ready for bonding the patch.

Fleet-Management Smart Card Reader

Background

Keyfuels were developing a new, advanced system for fleet managers to monitor fuel consumption across their commercial vehicle fleets by taking data from the vehicles’ tachometer and sending it to a central hub at each refuelling.

Brief

The electronics for an in-cab card reader unit was being designed, but thought needed to be directed toward the physical design of the unit. The unit needed to be robust and easy to use while not looking out of place in the drivers’ cab environment. Concepts were required before the chosen design would be developed for production.

Solution

A series of concept designs were sketched up by hand and the most promising ones developed as rudimentary models in Rhino. The selected design was then taken through a process of refinement and development in SolidWorks. The anticipated part-count was reduced from four injection-moulded parts to three during this stage. One moulding was also further developed to form an integrated light tube. Clip features were built into the part interfaces and these were tested using SLA prototypes. Further development was carried out until the final design was ready to go to production.