In custom prototyping and low-volume part production, 3D CAD models are the start of the conversation. And they are the focal point of the digital thread throughout the design and manufacturing process.
There are various questions to ask of the prototype team. Make sure you have the answers you want before you hire a partner. Here are the answers from ProtoLabs:
1. What types of CAD file formats can be uploaded?
- Injection molding: IGES, STEP, sldprt, prt, x_t, x_b, sat, dwg (3D), ipt and CatPart.
- CNC machining: the same as injection molding plus the stl format.
- 3D printing: stl is the preferred format for instant quotes in stereolithography (SL) and selective laser sintering (SLS), however, we can accept all of the aforementioned formats.
2. What files work best for which application?
- Stl for all 3D printing offerings.
- Neutral formats like IGES and STEP work great, along with native files such as SolidWorks for injection molding and CNC machining.
3. What should I expect from the quoting process?
- Fast response times — quotes are provided with a complete part analysis and cost in a matter of hours.
- 3D printing for SL and SLS processes can receive instant quotes, and direct metal laser sintering (DMLS) or custom finishing processes can receive a quote within 4 hours.
- Quotes for CNC machining typically arrive in 1 to 4 hours depending on part complexity and material selection. You also receive an as-machined analysis illustrating radii, challenging geometries or features that can’t be machined based on tooling availability.
- Quotes for injection molding, which are also available within hours, provide very valuable (and free) design for manufacturability (DFM) feedback . Our software analyzes draft, part thickness, flow analysis and other design considerations so adjustments can be made before any actual parts are manufactured.
4. What are some common protoyping methods?
- 3D printing offers thermoplastic-like materials using SL, which can produce clear, microfluidic and plated parts that can replace metal components. SL offers a range of material options as well as several finishing choices from plating, painting and polishing.
- 3D printing also uses SLS technology, which provides functional thermoplastic nylon parts that can be used in limited production. DMLS is another 3D printing process, in this case providing metal parts that are used in many industries including aerospace as production parts that can’t otherwise be manufactured.
- CNC machining, whether milling or turning, provides plastic and metal parts that can provide improved material properties over many 3D printing materials and can serve as a bridge between 3D printing and injection molding. Machining is also a great way to have jigs and fixtures produced for any application.
5. What determines the best prototyping method for my part?
This is an extremely difficult question to answer. You first have to ask yourself these questions to begin narrowing down your decision:
- What quantity do you require?
- What material do you need or what properties do you require?
- What is your budget?
- What is your lead time?
- What are your parts’ intended use? Marketing, functional testing, form/fit/function, strict prototype or low-volume production?
6. How does the toolpathing process work?
Proto Labs has proprietary software that we have created that works directly from a customer’s 3D CAD model. We toolpath for a CNC machined part or a mold design. During toolpathing, our software calculate the CNC code for our injection moldswhile our super computer breaks each component apart and reassembles it in a matter of minutes. We remove the human element from traditional toolpathing, which speeds up this process dramatically, but we don’t fully remove people from the equation. We still like to provide a human review of the mold design or orientation of the part being produced by CNC machining.
7. How do I convey tolerances?
Proto Labs has a set tolerance for each process and even breaks this down by the material that is being used to produce the parts.
8. How do I choose the prototype materials?
What are you looking for in a material — and what is the part’s application? That will help guide you to the right material for a prototype, whether plastic, metal or liquid silicone rubber.
9. What is the typical turnaround time and how much back and forth is acceptable?
- We are able to produce parts in 1 to 15 business days in all of our methods of manufacturing services depending on material, size, quantity and complexity. In 3D printing, we can have parts ready in 1 to 7 days, CNC machining in 1 to 3 days and injection molding in as fast as 1 to 15 days.
- We work on your schedule, and some back and forth is certainly anticipated. We want to be involved as early as possible in your design stages so we can help you produce the best part possible. Build orientation in 3D printing can be critical and we can help you design around part geometry that may not work well. At the same time, we can provide feedback on what draft or wall thickness you should be modeling on your part.
10. How much lead time should I allot for each step?
By working closely with Proto Labs early, you can work within our standard delivery options to avoid any expedite fees. Try to have completed designs that are approved by Proto Labs so that you allow a minimum of 15 days from when you require your parts. If this is not possible, we will work diligently on trying to meet your deadlines.
