Part without drawings: what to prepare to rebuild it in CAD

1. What you need the model for

Showing a part and manufacturing it again need different things. Tell me what you are after: documenting it, checking an assembly, rebuilding a broken part or getting a quote from a shop.

If you want to be able to modify the model, say so: a STEP file is geometry, not an editable history, and an STL does not replace a drawing.

2. Photos that explain the part

• General views from several sides.
• Close-ups of damaged areas, holes, bearing surfaces and engraved markings.
• A ruler or a familiar object next to it, as a size reference.

A photo helps to understand the part, but it does not replace measuring it. Don't dismantle anything or go into dangerous areas just to take photos.

3. Approximate measurements and the dimensions that matter

To assess the job, the overall dimensions and knowing whether the part can be moved are enough. Areas that fit other parts (shafts, housings, bearing surfaces) need more care: if you have the mating part or a bearing reference, tell me.

Always note the unit and where each figure comes from: measured, taken from a drawing or estimated.

4. Wear, breakage and repairs

A worn surface no longer has its original dimension. Point out play, cracks, corrosion or missing material, and whether there is an identical part, an old drawing or a catalogue reference.

A broken area is not rebuilt by symmetry without checking that the part was symmetrical.

5. What is delivered and what is left to check

Before starting we agree the format of the model and drawings, who defines materials and tolerances, and which dimensions still need checking.

Delivering a model does not certify a machine or authorise a safety-related modification.

Checklist for the first enquiry

• What you need it for.
• General and close-up photos.
• Approximate measurements, with unit and source.
• Parts that fit with it.
• Wear or breakage.
• Any documentation you have and can share.
• Where the part is and whether it can be moved.

Download the checklist as CSV

You don't need all of this for a first assessment. Don't send confidential documents through public channels.