A new automated wheel weight application system developed by 3M and Esys Automation can increase throughput speed of balanced wheels and tires in automotive assembly plants, the companies say

What’s the added value of cut-to-weight wheel weights?

Less scrap: Causes no damage to Class A surfaces like hammeron weights can; avoids waste associated with integer-value weights (cut waste, misapplies, etc.)

Better quality: Optimizes static and couple residual imbalance; uses automated placement for near-perfect application

Lean: Reduces the 12-24 individual SKUs used to identify integer weights to a single product.

OEMs can realize significant advantages in the assembly process by automating manual processes, with the added benefit of reducing production floor footprints and SKU complexity. According to OEM and Tier tire assemblers, the number one production bottleneck for tire and wheel assembly is the wheel weight application process.

Over the extensive history of automotive assembly, improvements in weighting and balancing materials have not translated into an improved application process for these materials, with manual applications resulting in reduced throughput and inconsistent precession, while further impacting the efficiency of balancers, mounters and inflators. 3M Wheel Weights are the first extruded adhesive weighting material with the potential to automate this process.

“3M and Esys worked closely to develop new, unique automation technology designed to dispense, cut and robotically apply the 3M Wheel Weight material in high-speed production lines – finally achieving the holy grail of tire and wheel assembly,” states Greg Piserchia, US Sales and Marketing Director, 3M Automotive Division.

Automating to achieve a precision application significantly improves OEM production throughput and first-pass quality. Results can improve wheel balance by as much as 30%, translating to better fuel economy and more even, reduced tire wear. Enabling broadbased production application of 3M’s weighting system further represents an industry-wide opportunity to eliminate lead-based materials associated with traditional wheel weight systems. While still in its initial production deployments in the United States and Europe, overall industry buzz is substantial, as evidenced by widespread interest and General Motors’ recent selection of the 3M/Esys solution in its Level A programme.

Creating a high-volume production system required Esys to invent an automated dispense and cut (DCS) system that could accommodate rolls of continuous weight material in order to produce individual weights at precise measurements, previously unachievable.

AutoW8t’s DCS module accommodates numerous complexities and scenarios for material supply, including transporting, mounting and feeding in confined spaces. Automated removal and disposal of liner waste without affecting production is also unique, accommodating multiple scenarios for collecting, receiving, blowing or chopping waste to create ‘lean’ disposal workflows.

The DCS feeds an automated weight application (AWA) system that interprets individual wheel geometries based on data already in the balancer to determine exact weight placement. This ‘self-taught’ robotic procedure eliminates traditional teaching paths using a force feedback sensor mode to evaluate new tire-wheel combinations, determine placement requirements, and store the data for future reference.

The innovation eliminates the need for cumbersome ‘learning’ techniques typically required by robotic applications. In addition, a patentable direct drive Esys innovation results in a total of just three moving parts to feed the robot, simplifying maintenance upkeep and minimizing OEM costs. Plus, reloads (splice-ins) of material can take place without interruption of production workflow with the AWA system.

AutoW8t, combined with 3M’s Wheel Weights on a roll, overcomes the typical space concerns associated with OEM brownfield deployment. The ‘package space’ is no larger than a traditional balancer or marking station. The flexibility of the system, which is able to accommodate multiple placement configurations, means that AutoW8t can be installed in most tire and wheel assembly processes with minimal modification. It requires nominal redesign and typically no expansion of production space allocations – a major savings in implementation cost and time that also removes a significant barrier with regards to technology adoption.

Esys Automation CEO Chris Marcus notes: “A single AutoW8t station replaces two traditional weight apply and balance stations. This not only eliminates the need for dedicated manual apply operators, it reduces average total cycle time of 12-14 seconds per station to a single station applying two weights in less than 10 seconds. Overall accuracy, including weight value and precision placement, is consistently better than 99% – which is impossible to achieve using traditional systems.”

Bringing the industry’s first automated wheel weight dispense-and-apply production system to market was not a ‘big bang’ process, but an iterative, multi-year collaborative effort among several key industry players. A close R&D relationship between Esys and 3M resulted in innovative product design improvements that enabled automated application of the continuous wheel weight material.

Esys Automation’s relationship with Kokusai, a highly-regarded wheel balancing supplier, was key to developing a unique balancing cell design and new end-of-arm tooling for robotic material application. Working closely with a major automotive OEM highlighted the importance of maintaining a compact physical package size. This helped to eliminate larger, traditional robot designs, resulting in the extraordinarily small footprint of AutoW8t. “Every automotive production system is a combination of many complex, interrelated products and processes,” says Marcus, “which is why collaborative innovation produces practical results quicker than a go-it-alone approach.”