Start with the problem you need to solve
You do not need a finished CAD file to start. Send photos of the surrounding assembly, a sketch of your idea, or examples of the shape you have in mind. Explain what the part needs to do and which dimensions are fixed. We review the brief and identify missing information before preparing a proposal.
Make the first version answer a question
A useful prototype has a specific purpose: checking the size of an enclosure, exploring a handle shape, or confirming where a mounting feature belongs. Tell us what you want to learn from the first print. Fit, appearance, and functional testing can call for different designs and levels of finish.
Review a version before it reaches the printer
Your proposal includes a named design revision, scope, and quote. You can review the available model preview and ask for changes before approving. Physical fit still needs to be checked against the real assembly; a model preview cannot establish that by itself.
What to include
Send overall dimensions, important clearances, attachment points, quantity, intended use, and your preferred date. If a dimension is unknown, mark it as unknown. We would rather ask a useful question than build a part around an invented measurement.