Stationary metal detector with a radiation monitor
Development of the inspection frame structure for single-unit production
Embedded Files
Technologies: sheet metal, machining, vacuum casting
Materials: steel, PU, wood, fibreboard, PC, XPS
Planned production volume: 2 units.
Operating conditions: indoor
My role: design engineer
Time spent on the project: 83 h.
Project duration: 2 mo.
The frame is installed at the entrance and allows detection of radiation emissions and the presence of metallic objects. If threshold values are exceeded, light indicators on the rear ends of the side panels are activated. The information is also displayed on the rear display (for the operator). At the front, there is a smaller display used to guide the inspected person (showing signals such as “wait,” “proceed,” etc.). In the indefinite future, a production series of 50–100 units per year was planned, but at the time of this work, it was urgently required to manufacture two units for an exhibition
The exhibition — in less than two months. Plus two weeks of holidays in between. One month left for manufacturing and assembly. That means only two weeks for design and approvals. Acceptable — provided the customer responds promptly to questions, of course
And there are always plenty of questions: datasheets for the electronics, how components are connected, what needs to be accessible, how and from where the device is powered — and a hundred other uncertainties that only the client can clarify
When I joined the project, the design concept had already been defined, along with a list of the main components that determined the device’s functionality and had to be placed within that design.
The design, of course, did not take any specifics into account — only the stylistics, fitted within approximate mass-and-size constraints. Something like: the central block — according to display size, width — according to passage width.
However, to their credit, the designers did account for transport convenience and ease of on-site assembly/disassembly by including visible connecting fasteners in the exterior design 🥰
The frame can be used either standalone or as part of an inspection complex 👆 👉 — with a turnstile equipped with a gas analyzer
Initially, a traffic-light-style indicator was planned: a red lamp behind the “stop” pictogram and a green one behind the “go” pictogram. Apparently, the futuristic design inspired thoughts of a more “intelligent” and versatile device. In the end, it was decided to install a full-fledged display instead
If there had been a production run, extruded profiles with grooves would have been used on the ends of the side panels, into which a light-guide insert (most likely also extruded) would slide — a sort of slider. However, for two prototype units, extrusion was out of the question, and creating such grooves in silicone casting is not easy. Therefore, the profiles were left with simple shelves, onto which a long light-guide strip, cut from a sheet, was glued
The lower half of the central unit’s housing is fixed with magnets — for quick access to the electronics (a customer requirement)
A classic case where the device’s form factor determines its structural design: two panels connected by a crossbar
Since the filler of the side panels — which contains the functional part of the detector — must start almost at floor level (you’d be surprised what people try to smuggle in their shoes), it was necessary to abandon the lower crossbar of the frame. Considering that all parts of the side panels (apart from the mechanical fasteners) are glued together, and a plastic support is attached at the bottom — that’s perfectly acceptable. The frame ends were supposed to have a two-meter-long profile, which cannot be cast in silicone, so its role is performed by four 50 cm segments instead
In the original design, the central block housing was intended to be white, while the side “tubes” and end inserts for the displays were black. Therefore, they were made as separate parts with intermediate connectors
Of course, there was some force majeure: the ordered 13.3-inch display broke during transport. Fortunately, this became known during the design stage. Since an 11.6-inch display was available, it was decided to provide an adapter frame (not shown in the image) for a temporary smaller screen — until the new one arrived
Production files
including a parts list (BOM) with all components and assemblies in assembly order, key process parameters, division into subcontractors. And a full set of drawings
Summary of the work done
Based on the design concept and requirements, I developed the structural housing component of the device for single-unit production
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