From drawing to dock · step 3 of 10
Step 3: Prototype. A sample you can hold.
Before a production tool is built, you hold the part. First samples are usually 3D-printed, CNC-machined or made from a small tool, and they typically take about 7 to 10 days once the files have been reviewed. Their job is to prove the design, not to prove the factory.
What happens in this step
The files are reviewed, then the part is made the fastest right way.
Jack starts by reviewing the files: does the geometry make sense, will the part do its job, and which method gives you an honest sample. Then the sample is made by the method that fits the part:
- 3D printing when the shape matters most and speed is the goal. Jack uses it whenever it can answer the question.
- CNC machining when the sample has to be strong, precise or made from a real production material.
- A small tool when you need molded samples, or more than a handful, before the production tool.
Each method answers a different question. A printed part shows fit, look and feel. A machined part can be tested for strength. Molded samples from a small tool show how the real process behaves.
What you send us
The drawing, and what the sample must prove.
- The CAD and drawing from step 2, or whatever you have if step 2 is happening alongside.
- What the sample has to prove: fit, look, function, strength, or a buyer's first review.
- How many samples you need, and whether they must be in the production material or color.
- Any part it has to mate with, so the fit can be checked.
What you get back
Parts to test, and a list of what to change.
- Samples you can hold, fit and test, usually in about 7 to 10 days after the file review.
- Notes on what the sample showed and what should change before the production tool.
- A clearer view of the tool the design needs, and of whether that tool will pay for itself.
Prototype or production tool?
Let the volume decide.
Tooling only makes sense when the volume is there. Published figures put the break-even between molding and 3D printing or CNC machining at typically 500 to 5,000 units, depending on geometry and material. Below that band, a short run of printed, machined or small-tool parts can be the better first step. Above it, the production tool pays back quickly.
For published tool price ranges, including aluminum prototype tools, see what an injection mold really costs.
Common mistakes at this stage
What a sample can and cannot tell you.
- Approving a printed sample as if it were a molded part. Printed and molded parts behave differently.
- Skipping the sample to save a week, then changing the design after steel is cut.
- Testing only how it looks. Check fit, function and assembly too.
- Ordering one sample when the test will destroy it. Order enough for the tests you plan.
- Treating a hand-finished sample as proof the line can repeat it. That comes later, at the first article.
Before you move on
What the sample has to prove before steel is cut.
The prototype stage ends when the design stops changing. That is the point where a production tool becomes a safe spend, because a tool is the most expensive thing in the program to change.
- The part fits every mating part, and assembles the way the line will assemble it.
- It does its job in the tests you care about, repeated on more than one sample.
- Your buyer, your team or your end user has handled it and signed off the look and feel.
- Every change the sample showed has been made in the CAD, and the revision updated.
- The volume decision is made: production tool now, or a short run first.
If the first sample raises questions, a second round is usually cheaper than guessing. Samples are quick; steel is not. It is normal for a product to go through more than one sample before the design is frozen, and it is far cheaper than changing a finished tool.
Questions
What people ask about this step.
How long does a first sample take?
Usually about 7 to 10 days after the files are reviewed, depending on the part and the method.
How are prototypes made?
Usually by 3D printing where it can answer the question, by CNC machining when the sample needs strength or a production material, or from a small tool when you need molded samples.
Should I build a production tool or a prototype first?
Let the volume decide. Published figures put the break-even against 3D printing or CNC at typically 500 to 5,000 units, depending on the part.
Can the prototype be in my production material?
Often, by CNC machining or from a small tool. A 3D print is usually in a similar material, not the exact production resin.
Will you sign an NDA before making samples?
Yes. We'll sign your NDA, or use ours, before you share details.
Related
Have something to make?
Send what you have. Jack reads it himself, and we’ll sign your NDA — or use ours — before you share details.