Tier 1 leak test fixture that delivered Cgk 2.04 when the competitor couldn't meet the spec
The client quoted Lübeck for a Tier 1 project for automotive OEM with 11 models. Lübeck spent three weeks calculating volume and cycle time. The first round was assigned to another integrator with a different approach — but after months without meeting specs on any model, the second round opened. Lübeck won it.
The previous solution vibrated. The fixturing lacked repeatability.
Automotive OEM required Cgk > 1.33 and GR&R < 10% on a leak test at 1 sccm with 420 kPa — sensitivity where any particle, humidity, or external airflow falsifies the reading. The previous solution failed to meet specifications on any model for months: induced mechanical vibration and non-repeatable fixturing were the root causes.
What opened the door to the second round was a previous Lübeck case within the same company: the refurbish for Japanese OEM was still operating without issue. The client's Quality Manager had been on Lübeck's side from the start, but didn't have the final decision.
Mechanical stability as the foundation — no vibration, repeatable fixturing
No induced vibration. 12 mm thick ground aluminum base plate. All sealing geometry is supported from that plate. Control without external PLC: all logic lives in the CTS Sentinel i28 I/O via DB25 connector with intermediate terminal blocks and three controlled solenoid valves.
Bracket sealing — Viton o-ring 80 Shore A
Fixed nest with o-ring in custom inverted trapezoid cavity. Compression limited to 20% of diameter. Nest ground on both faces. Two conical pins as poka-yoke. Clamping with SMC MGPM guided actuator.
Radial sealing — CTS CO33-AF expanding seal
Mounted on SMC MGPM guided actuator. 6-axis compensation system (guide screws + Redux springs) that allows the seal to "find" the tube center and absorb dimensional variations without forcing geometry.
Environmental isolation
Structural aluminum frame with polycarbonate panels on 4 sides. At 1 sccm, any external airflow generates noise in the reading. The walls isolate the test environment. Scrap chute and pushbuttons integrated into the frame.
Lab-grade test air
Pneumatic accumulator, FRL, sub-micron filters and pre-filter, refrigerated dryer. Humidity and particles eliminated at the source. At 1 sccm, every micron of contamination counts. AIAG MSA / VDA 5 for Cgk and GR&R study.
Cgk 2.04 — over 50% above automotive OEM minimum spec
"Wow, this looks great — exactly what we needed, something simple but well done."
— Client Quality Manager, upon seeing Lübeck's machine on the floor
We diagnose the real problem.
Not the symptom.
If you have a Cgk that won't rise or a test fixture that doesn't meet the end-client specification, we can diagnose where the real variability is and propose the correction.