Case Studies

Custom visioin inspection for fasteners

Customizable Vision-Based Inspections

Posted in LabVIEW, Machine Vision, Test & Measurement Automation


DMC's client manufactures custom fasteners as part of a product line that includes a wide range of sizes and materials. To ensure quality, the client uses a vision-based test system to inspect features of these fasteners according to unique part specifications. Due to the varied nature of the work, the system must have a high level of customization to accommodate the client’s end customer needs.

The current inspection system is costly and does not meet the client’s needs for future use. DMC is generating a system in LabVIEW which will control this tester and allow customization to meet the client's needs. 

DMC is a certified NI Vision Specialty Partner, meaning we have been recognized by National Instruments as a leading provider of vision inspection systems and software.


The high-level operation of this system involves a fastener feeding system that loads fasteners onto a dial. The system can run as fast as 1000 parts per minute for some of the parts. Each fastener’s position is tracked by the FPGA as the Kollmorgen Servo rotates the dial at speeds from 200-800 rpm, moving fasteners past several Basler cameras. The images from these Basler cameras are processed using NI VBAI based on specific profile guidelines configured by the client.

The cameras take side and top view of the fasteners. The images allow them to search by screw head to make sure it is the right size, shape, length, pitch, etc. from the side of the screw.

The results of these inspections are sent to the LabVIEW program where each screw is matched with its correlating pass/fail data from each camera. Each fastener that passes the inspection is blown off the dial with a puff of air and passed through a chute into boxes on a pack line which are automatically progressed as boxes become full. The inspection system is boxing up the parts, so they are ready for shipment and counted into appropriate quantities when they come off the line.

In this case, the client is generating the NI VBAI inspections for many reasons.

1. VBAI has an easy to use interface for generating inspections, which makes it simple for the client to specify inspections without in-depth programming knowledge.

2. The client has the most in-depth knowledge of the inspections that need to be performed, which makes them the ideal candidate for generating those inspections.

3. The client generates custom fasteners, which means that new products are always in production. Using VBAI eliminates the need for the client to come back to DMC to generate new inspections for each new product.

Learn more about DMC's LabVIEW Vision Expertise. 

Customer Benefits

  • Software customized to meet client’s specific needs
  • Reduced cost for each additional test stand built
  • Flexibility to apply the software to multiple types of test stands
  • Higher running speeds for more throughput on each machine