Frequently Asked Questions
Technical And Project Related Questions
What tolerances can you achieve?
There is not a given set of tolerances that fits all processes and materials. In every case, the final tolerances on your part will depend on a number of factors, including but not limited to:
- Part size
- Design geometry
- The number, type and size of features
- Surface finish
- Manufacturing process
We will review your design and provide a design for manufacturing review, pointing out any areas where we may not be able to achieve your desired tolerances. It’s helpful to us if you can specify which areas in your design have critical tolerances that must be met and which can be slightly modified if needed to reduce time and costs involved. Here are some general tolerance guidelines:
Tolerances for vacuum casting will depend on the tolerance of the master model, the type of casting resin being used, and the part’s geometry. Typically we apply a tolerance of + 0.15% deviation from the master model. For parts requiring heat treatment we may machine an insert such as Tufnol which prevents further shrinkage during heating.
SLA 3D printing
When using SLA, both typically have a lateral (X and Y axis) deviation of about + 0.1mm, and a vertical tolerance (Z axis) of + 0.3mm. Note that much finer tolerances than these can be achieved with post machining and finishing.
Unless otherwise specified, we comply with the DIN 16901 standard tolerances for plastic injection moldings. It is possible with careful thermal, time and pressure control to have very accurate parts. We need to know your requirements in advance so that we can manage key features in the tooling and molding process. As a general rule, you should never make more than one feature very accurate in the design. That feature can be repeated across the part, but to make a whole series of very different features very accurate is impossible for any molding company to achieve – you end up chasing your intolerances around the part. You get one feature right only to find another one slightly off.
Our general tolerances for CNC machining of metals is DIN-2768-1-fine and for plastics DIN-2768-1-medium. Tolerances are greatly affected by wall thicknesses, material choice, and geometry, so we will seek to advise as to achievable tolerances for each part. We pride ourselves on wishing to help our clients achieve their desired tolerances that are better than DIN-2768-1, but we work on a “best effort basis only” if the tolerances stated are tighter than our stated standards. The reason we refuse to be held accountable for very tighter tolerances is that we are a prototype factory and very tight tolerances present a huge risk due to the nature of our work.
All manufacturing and technical specifications need to be clearly specified in the 2D drawings in order to be followed.
Can I get 'rapid injection molded' parts in days in the USA and Europe?
How do you ensure your quality?
- A full design for manufacturing (DFM) review upon initial inquiry. This will be performed by our skilled engineering team, who will alert you to any issues before work begins.
- All incoming material (metal and plastic) is 100% inspected using our in-house metrology equipment. This includes OES, XRF and PolyMax spectroscopy.
- In-process and first article inspection.
- Comprehensive final inspection with full report. See here for more information about our range of inspection equipment.
Do you provide export molds?
What are shipping terms for rapid prototyping orders?
Can I use my my own material and/or master model for production?
Can you paint customer-supplied parts?
Pricing And Shipping Related Questions
How does Star Rapid compare to suppliers in the west on price?
This is a complex question with many variables. Some of the components include the cost of locally-sourced raw material vs. imported material, currency fluctuations between different countries, energy costs and how technology and labor-intensive a given project may be. In general, the greatest savings will be realized for labor-intensive projects, where local labor rates can be one-sixth their overseas’ counterparts, although this disparity is becoming more equalized as China develops. Historically speaking, averaged over many years and many types of products, we maintain a 30 % price advantage to our competitors in western countries Here are some other considerations: For SLA prototyping, there is no price advantage to making them in China. Quite the opposite, it will be much more expensive based on shipping costs alone. However, if 3D plastic printing is only the foundation for more extensive secondary processing (painting, sanding, overmolding, vacuum casting, etc.) then it starts to make sense. Vacuum casting prices can be 30-50% less than in the West, based on labor rates. The cost driver here is the price of imported Axson casting resin. Plastic injection mold tooling is consistently 50% of the pricing in Europe and America when using semi-hardened steels. Pressure die cast tools and processing is 25-50% cheaper. This is because there are no shortcuts to this process, and no way to do it “rapidly”. Die cast tools must be made carefully and fully heat-treated, which is labor intensive and time consuming. This is where great economies can be realized for aluminum and zinc die casting in particular, where the cost of raw material is not a big driver.
How does Star Rapid compare to other Chinese suppliers on price?
How do delivery times compare to the West?
I have an idea, can you do drawings and make parts for me?
Is the lead time in working days or calendar days?
Lead times are quoted in working days. As per our Terms and Conditions, quoted lead times commence only after completion and confirmation of design for manufacturing review and the beginning of actual production.
What are the shipping terms for rapid tooling order samples?
How long does a quotation take?
Do we have insurance on delivered goods?
Can I pay an express fee and get my parts sooner?
How much import duty will I need to pay for my goods?
What are HS codes?
How financially secure is Star Rapid?
Can my company get credit with Star Rapid?
How can I pay Star Rapid?
- Bank to bank wire transfer. Star has accounts in Hong Kong and Zhongshan, China.
- Star can send you a PayPal invoice and you can use your PayPal account or credit card to pay.
Company Related Questions
How do I know my design will be kept confidential?
What if we are not completely satisfied with the parts we receive?
Who owns Star Rapid?
Star Rapid (previously known as Star Prototype) is 100% owned by British engineer Gordon Styles. The subsidiary factory Star Rapid Manufacturing is 100% owned by Star Rapid Limited, and therefore owned 100% by Gordon Styles. There are no investors or shareholders.