Frequent mistakes when ordering a prototype (and how to avoid them)

Ordering a prototype might seem like a simple task: you choose the technology, upload the file, and wait for the result. But the reality is that without the right information, it's easy to make mistakes that can affect quality, cost, and lead times.  

In this article, we explain the most common mistakes when requesting a prototype and give you the keys to avoid them, whether you're an experienced designer or it's your first project. 

Uploading an incomplete or poorly prepared file

One of the most common errors is uploading CAD files without verifying they are ready for manufacturing. Typical failures include: 

• Open or non-closed surfaces. 
• Incorrect scale.
• Geometries that are impossible to manufacture (e.g., walls that are too thin).
• Files with unclear names or no updated version. 

How to avoid it? 

Check the model carefully before uploading. If possible, export in STEP or STL format depending on the chosen technology, and ensure the units of measurement are correct. Always include a final version validated by the designer. 

Not defining the prototype's objective

Not all prototypes serve the same purpose. A visual prototypedoes not require the same precision or materials as a functional or structural one. Many errors stem from not communicating what is expected from the prototype: Is it for display at a trade show? Will it be subjected to mechanical stress? Does it need to withstand heat? 

How to avoid it? 

Clearly indicate the prototype's use. This allows selecting the appropriate process (3D printing, CNC machining, silicone...) and adjusting materials, tolerances, and finishes according to actual needs. 

Choosing the wrong material

Another common mistake is choosing materialsthat do not match the design requirements. Sometimes the cheapest option is chosen without considering if it will be strong enough or have the desired appearance. 

How to avoid it? 

If you don't know the materials well, consult with your supplier. At Proto&Go! we advise you on the available options based on your design, so you can balance cost, appearance, and functionality without compromising the result. 

Not taking tolerances and fits into account

Designing without considering manufacturing tolerances is one of the main reasons why a prototype does not fit, does not assemble, or does not perform its function. This is especially important for parts that must fit with others or include fixing systems. 

How to avoid it? 

Adjust your CAD design considering el manufacturing process. If you are assembling parts together, consider reasonable clearances and avoid limit fits. Ask for technical advice if you have doubts. 

Do not validate times and expectations

Requesting a prototype urgently without validating real lead times can cause unnecessary delays or frustration. Each technology has its own times, and sometimes a material change or a design adjustment can lengthen the process. 

How to avoid it?  

Check estimated lead times from the start. At Proto&Go!, the online request system allows you to know the cost and lead time in less than 24 hours. If you have critical dates, consult us before placing the order to ensure feasibility.