Our goal at Reata Engineering is to produce the highest quality parts in the fastest and most cost-effective manner possible.
There are so many steps involved to manufacture each part—and as the saying goes, the devil is in the details. This principle applies to every aspect of the contract manufacturing process, including the prints customers provide.
If critical details are missing from your print, we’ll always work closely with you to clarify requirements and specifications. But including key information up front will minimize back and forth communication to get you the parts you need—and save you time and money.
How to Improve Prints for Contract Manufacturing Services
Follow these tips to optimize your print for contract manufacturing services:
1. Keep title block tolerances general
The title block of a print contains default tolerances that manufacturers apply throughout the entire part. Setting those tolerances too tight could mean paying for tight tolerances on more features than necessary.
We advise keeping tolerances in the title block general and specifying tighter tolerances individually at each feature location in your print to prevent costly overengineering.
Our standard recommendation for block tolerances is +/- 0.005″ – 0.010.” Sometimes customers use fractional tolerances in the title block, but because most of our customers come to us for precision machining, we rarely see tolerances depicted that way.
The information in the title block also determines whether we use English or metric settings when making your part. Conversions between the two settings aren’t always exact, so manufacturers and customers must align on the chosen system for a project to ensure accuracy.
2. Maintain consistent tolerances between models and prints
It’s common practice for engineers to submit a 3D model along with their prints and instruct manufacturers to machine their parts according to the dimensions in the 3D model. But if the dimensions aren’t consistent between the two files, this conflicting information can lead to discrepancies during the contract manufacturing process.
While manufacturers typically machine to the model’s dimensions, quality inspectors reference prints during inspection. If, for instance, the engineer rounded up their tolerances from three decimal places in the 3D model to two in their prints, the quality inspector may conclude that the part doesn’t meet specifications, or is at the tolerance limits. When this confusion occurs, it causes unnecessary back and forth between our internal teams and may even result in a phone call with the customer to clarify the correct tolerances. Maintaining consistency among 3D models and prints helps prevent this problem to ensure accuracy and on-time delivery.
3. Call out detailed plating specifications
We work directly with trusted plating vendors to manage all finishing operations for our customers, and we need to have all the requirements so we can communicate clearly to ensure you get the finishing you need.
Here are a few critical plating specifications to note in your print:
- MIL specification. Instead of calling out something general like “black anodize” in your print, note the specific MIL-spec you want (e.g., black anodize per MIL-A-8625, Type II, Class 2). Check out this handy resource for additional information on which MIL-spec to use.
- RoHS compliance. RoHS stands for Restriction of Hazardous Substances. If the finish on your part needs to be RoHS compliant, we’ll need to communicate that to the plater up front.
- Pre or post-plating dimensions. The plating process inevitably adds a layer of thickness to each part. For this reason, it’s important to note in your print whether the dimensions of your part are pre- or post-plating. For example, if you specify that your dimensions are post-plating, we’ll machine your part “out of print” to ensure it meets specifications after plating is complete. If this information is missing, our default is to assume pre-plating dimensions are indicated.
If you need contract manufacturing services for your next project, Reata Engineering is here to ensure you get the exact parts you need. Request a quote to work with us!