Sample & Drawing Technical Evaluation

Most magnet projects do not start from a clean specification. They start from a sample taken out of a motor built years ago, a 2D drawing that defines the outline but not the grade, or a 3D model with no magnetization direction marked on it. Those are workable starting points, but none of them tells a factory what to make on its own. This capability turns what you already have into a documented basis for quotation, tooling and inspection, and states which parts of that basis are measured facts, which are our preliminary reading of the evidence, which would still need testing, and which only your approval can settle.

The Customer Problem

A magnet is defined by more than its outline. Two arcs of identical shape can be pressed wet or dry, oriented in different directions, magnetized in different patterns and ground to different tolerances, and the resulting parts behave differently in the same assembly. When a drawing carries only geometry, grade, orientation and magnetization pattern are left to whoever quotes the job. A sample answers part of that, but a sample that has been in service is evidence with a history: wear, corrosion or partial demagnetisation can mean the part in your hand is no longer identical to the one that was made, and if the original specification is gone, nobody can yet say how far it has moved.

• The grade, orientation and magnetization pattern are undocumented, so the part cannot be reproduced to the sample.
• Fit dimensions are recorded, but the tolerances that matter for assembly are not separated from cosmetic ones.
• Coating or surface condition is visible on the sample while the drawing says nothing about it.
• Nothing states which features are critical to the customer's function, so inspection effort is spread evenly.

What We Do

We review the available drawing or sample to clarify dimensions, magnetization and manufacturing requirements. We evaluate the sample and the documentation together, and we keep four levels of certainty apart in everything we report:

• Observed or measured facts. What the drawing and the sample actually show: dimensions read and compared, features identified, coating or surface condition recorded as a specification item.
• Preliminary inference. Where the available information supports a reading of the part, we give a preliminary material and process judgement and a first-round substitution feasibility assessment — stated as an inference, never as a test result.
• Testing or sample validation still needed. Where material grade or magnetic properties cannot be confirmed from the available information, we identify the additional testing or sample validation needed before production. Where magnetic properties have to be confirmed, the appropriate testing — method, equipment or test provider, and conditions — is coordinated and recorded per project, and the result is reported as such.
• The production basis, after you approve it. Only once you confirm the drawing, technical requirements, sealed master sample and agreed packaging do they become the basis for serial production.

Alongside that work we inspect the coating or surface condition, establish the magnetization pattern and direction the assembly actually requires, and coordinate the partner-factory engineers and the customer's engineers around the questions that remain open. ProfurtherMag is the project coordinator: production happens in partner factories, and drawing or sample review is carried out with those factories' engineers as the project requires.

What one evaluation actually returned

An example from a delivered project, with the figures attached. A pump motor's stator arc arrived as a sample with no grade, no magnetization direction and no tolerance intent on the sketch. The review returned this as the production basis:

The line worth copying is the tolerances. The inner radius may only grow and the wall may only thin, so both limits are biased the same way and the magnet can never intrude into the rotor space. Nothing on the sample states that intent — it came out of reading the part against the assembly it sits in, which is the part of a sample evaluation that measuring alone cannot produce.

The opposite failure is just as instructive. A fan and blower magnet project from 2018 was rejected at the customer's assembly because the end chamfer was too tight: the magnet could not reach its seating point on the plastic holder, so the U-clip would not retain it. Not one dimension on the supplied drawing was out of tolerance. That is why the review separates the dimensions the drawing calls out from the features the assembly actually needs, and why samples in that series are confirmed on the customer's line rather than on the bench.

Expected Outcome

Deliverables are confirmed per project. Depending on what the sample and the documentation support, they may include:

• a measurement summary of the sample against your drawing;
• the magnetization observation: the pattern and direction found, and what the assembly requires;
• the specifications and drawings still to be confirmed, listed as open items rather than assumptions;
• a manufacturing-route recommendation, and a sampling plan for confirming the part;
• the additional testing or sample validation needed where a property cannot be confirmed from the available information.

A complete reverse-engineering result is not promised for every sample, and the record is written so that no inference reads as a measurement. You see exactly which parameters are settled, which are provisional and how each one would be checked, instead of discovering after first articles that the factory interpreted a legacy sample differently. Where a used or demagnetised sample, or a missing original specification, limits what can be concluded, that limit is stated in the result rather than left to the first delivery.