Build to print manufacturing in India means you provide a drawing and the maker produces the part exactly as drawn. The same model applies to contract manufacturing for engineering work and to custom CNC parts, where a machining shop cuts parts from your files.
It works well when your drawing is complete and your ownership terms are in writing. It goes wrong when either is vague.
What does a complete drawing contain?
A maker can only build what you define. A complete package includes:
- A dimensioned drawing with tolerances, surface finish and geometric tolerances where they matter.
- The material grade and the standard it follows.
- Heat treatment, coating or plating, with the specification.
- A 3D model where possible, for CNC programming.
- Inspection requirements and the documents you expect with each lot.
Who owns the design and the tooling?
In build to print, the design is yours. The maker supplies the manufacturing process, not the idea. Put in writing that drawings, models and special tooling stay your property, and that the maker may not use them for others. Sign a non-disclosure agreement before you send the files. Protecting drawings and designs goes through the practical steps.
If the maker has to improve the design to make it manufacturable, agree who owns the changes and who approves them.
If you supply special gauges or fixtures, mark them with your name and keep a list. Ask the maker to confirm in writing that they hold them for you, and that they will be returned or destroyed on request.
Where a part is later moved to another maker, you will need the drawings, the inspection records and any tooling. Having these clearly yours makes a transfer simple. Without them, you may have to start again.
How do you approve the first parts?
Before production, ask for first-article samples with a full inspection report against the drawing. First article inspection explains the format. Do not release production until you approve in writing.
For a new part, follow the staged route described in developing a component from a drawing, moving from sample to pilot to production.
How do you choose a contract manufacturer?
Choose a plant that already makes parts similar to yours. Ask to see its machines, inspection equipment (such as a coordinate measuring machine where tolerances are tight), and sample reports. Confirm that it manufactures the part itself, since a trader may subcontract it without your knowledge. How to tell a trader from a manufacturer shows how to check.
Agree on subcontracting: whether any operation, such as plating or heat treatment, can go to another firm, and whether you must approve it.
Think about the commercial side too. Agree on a price validity period, how material price changes are handled, what happens with rejected parts, and who pays for rework. State the inspection plan in the purchase order, for example the sample size per lot and the characteristics that are measured on every part.
Where parts are safety-critical, add a rule that no change of process, material or subcontractor may be made without your written approval.
Next step
We find and audit engineering shops, check first-article reports, have lots tested and supervise production and loading. If you have a drawing to place, book a free sourcing review.