Top

  • Aero

controls

DETAILED CASE STUDY: CNC

When a rocket-engine manufacturing company has a problem, finding a solution sometimes truly does involve rocket science. Due to their critical nature, key parts of rocket engines must be X-rayed to ensure their integrity and thus their safety.

The process traditionally has been time-consuming and inefficient. Even with the most skilled technicians, it has been more of a trial-and-error experiment than an effective manufacturing strategy. This manufacturer called on us, and we automated the process using a custom Computer Numerical Control system.

the-pointPROJECT DETAILS

ROI: 24 months

Project duration: 12 months

Team
Client: 3 engineers
Concept Systems: 3 engineers

Concept Systems’ time on site: 21 days

Pain points

  • Transmitter and receiver had to be manually located using yardstick and twine
  • Repeated operator entry into the x-ray chamber

Results

  • Faster, more consistent registration
  • Improved speed
  • Improved inspection accuracy
  • Elimination of re-inspection
  • Reduction of ergonomic risk: repeatedly opening the heavy lead-lined door

Technology used

  • Siemens 840D/PL CNC
  • SIMODRIVE 611D Digital Drives

SOLVE YOUR PRODUCTION PROBLEMS

Replacing ‘trial-and-error’ with precise control

To ensure quality control, rocket engine parts are inspected using X-ray images. Accurate X-rays are crucial. One of the big challenges is making sure the X-ray tube, the part to be inspected and the image receptor are perfectly aligned.

Having a technician manually position each element creates plenty of potential for inconsistency. It also requires the technician to leave the lead-lined room after positioning the element, take an X-ray image and examine the image to determine whether the components are properly positioned. If not, the technician makes adjustments and takes more images.

Given that each engine part requires inspection at multiple points, it’s easy to see how large chunks of time can be eaten up with this process.

Building on the customer’s previous improvements

This customer was all too familiar with the challenges, and had refined the process to cut down on human error. They incorporated motorized arms that held the X-ray tube and image receptor. However, loading the part and setting the X-ray tube and image receptor were still manual processes, and the data points from the registration process needed to be translated and the arms manually jogged into place. So human error continued to come into play, and the company saw room for continued improvement.

They called on us to develop a custom Computer Numerical Control (CNC) system to further automate the process.

The CNC solution: precise and programmable

With the solution proposed and provided by our engineers, the CNC now controls the arms, positioning them based on the registration information entered by the technician and a preprogrammed recipe for that part. The X-ray tube and image receptor move in concert around the part, always opposite each other, stopping to take the necessary shots and then moving on to the next. Since both arms are under common CNC control, the preprogrammed moves are tightly synchronized around the part, avoiding any fixed obstacles.

The operator can adjust the position of the devices from the workstation, and program in routines for repeat parts.

In addition, the technician now only enters the room to load and register the part and then unload it when the inspection is completed. The need to rerun parts is essentially eliminated when the part is properly registered and the data is correctly entered. With the new system, if an error is made it can be quickly detected and corrected.

Potential for more efficiency gains

After these improvements, parts are loaded, registered and inspected in 30 minutes, on average, compared to a previous average of two hours. While this is a significant productivity gain, we see potential for even more gains and are eager to take the system to the next level.

Automating the registration process utilizing laser scanning technology would simplify the technicians’ task to simply loading and unloading the part. The result would be still faster, more reliable inspections.