Not every project arrives with a drawing. Plenty of people have the part in their hands and nothing else: a broken original, a discontinued casting, a bracket that no longer appears in any catalogue. The custom work process covers this case directly. Where there is no drawing but there is a sample, the sample goes to an engineer, who gauges the dimensions and produces a drawing, and the mould is then made from that drawing.
That short sequence contains the important idea. The sample is not copied by eye. It is measured, and the measurements become a controlled document that the rest of the work is built against. Negotiation comes first and the project starts after it, so the scope is agreed before metal is cut.
Gauging a physical part means capturing every feature the new part has to reproduce. Overall size, the position of holes and their diameters, wall sections, angular relationships, radii and the shape of any mating face all have to be recorded. On a used part, some of those features are no longer what they were when it was new, and part of the engineer's job is telling wear apart from original design.
Where a part is worn, distorted or corroded, the drawing has to record the intended geometry rather than the worn condition. That is a judgement call, and it is worth discussing with the customer, because the difference between reproducing a part and reproducing the design it started from decides whether the replacement fits or not.
A drawing is what makes a project repeatable. It fixes the dimensions, materials and special requirements so the mould is cut to a target rather than to an impression, and it gives both sides something to check finished samples against. Where a customer does have a drawing containing dimensions, materials and special requirements, the mould is made from that drawing; the sample route exists to produce the same document when none exists.
The drawing also carries the choices the outside of a sample cannot show: material grade, surface finish, colour and any logo or marking. The services offered include customised 3D file, materials, colour, logo, drawings and surface finish, and all of those are easier to state once the geometry is written down.
The process distinguishes two mould routes. A sample mould is smaller, costs less and is used only to make samples. A big mould can make both samples and mass production. For a one-off, or for a project still being evaluated, the sample mould lets the customer hold a real part without committing to production tooling. For a project that is going ahead, the big mould does both jobs.
The order of work after mould making is the same either way. The mould is tested, samples are then made, and an engineer measures their sizes and tests hardness to confirm quality. Only after that do samples go to the customer for testing, and mass production starts after the customer confirms them.
A sample is a question, not an answer. It has to be fitted, run and looked at. If it is a bracket, does it line up with everything around it. Confirmation is the customer's step, and it is where a dimension that was correct on paper but wrong in the car surfaces.
When the customer confirms, mass production follows. When a change is needed, the drawing is the place to make it, because a change recorded there carries through to the tooling and to every part made afterwards.
Working from a sample suits replacement items, discontinued items and anything where a physical original exists but documentation does not. It is also a good fit for other parts that are simple enough to gauge accurately and whose function is obvious. It suits less well a part where the sample is a worn or modified version of the original and the intended geometry is genuinely unknown.
In that situation the honest options are to reconstruct the design intent with the customer's input, or to accept that the new part will reproduce what was sent, wear included. Both are workable, but they are different products, and the choice should be made before the mould is cut rather than after.
