Amts Presentation

On-Machine Probing effects on OEE AMTS 2008 Moise Cummings TechSolve, Inc.

Benét Laboratories “ Research was sponsored by the U.S. Army Benet Laboratories and was accomplished under Cooperative Agreement Number W15QKN-06-2-0100. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of U.S. Army Benet Laboratories or the U.S. Government. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation heron.”

Smart Machine Technology Thrust Areas Intelligent Machining Network Health & Maintenance Machine Tool Metrology Intelligent Planning Tool Condition Monitoring On-Machine Probing

Definition of On-Machine Probing American Machinist m agazine 2008 survey of benchmark companies Perceptions of On-Machine Probing What is OEE (Overall Equipment Effectiveness)? Definition of OEE Calculating OEE Six big losses in a plant Obstacles to OEE OEE and On-Machine Probing Test performed at TechSolve Success Stories Conclusions Outline

On-Machine Probing An inspection process within a machine tool that requires minimal use of peripheral inspection equipment or additional operators Data is used to make process adjustments to minimize non-conforming parts Benefits to Industry Work offset verification Detects maladjusted fixtures Collects SPC data Reduced material handling On-machine rework In-process correction On-Machine Probing U-TOL L-TOL UCL LCL

2008 Machine Shop Benchmark Survey Analysis From the July 2008 issue of American Machinist “ This year, there was a noticeable increase in the uses of in-process measurement, coordinate measuring machines, barfeeders and prefixturing of workpieces, especially for shops in the benchmark shop categories.” Increasing the overall equipment effectiveness (OEE) is one of the hallmarks of the machine shops in the benchmark categories

Industrial Perceptions Probing diverts time from machining and increases cycle time Instead of focusing on cycle time, we should evaluate overall equipment effectiveness (OEE) Probing routines are difficult to write and use State-of-the-art software makes writing routines easier and more user-friendly Once written, routines can be used on repeat parts The probe is only as accurate as the machine itself

What is OEE? Best practice way to monitor and improve the effectiveness of a manufacturing process Organizes any productivity losses into three components to provide a gage for process improvement Availability, Performance, and Quality

How is OEE calculated? OEE = Availability X Performance X Quality Availability = Operating Time / Planned Production Time Performance = Ideal Cycle Time / (Operating time / Total Pieces) Quality = Good Piece / Total Pieces World-class performance OEE = 85% The OEE percentage by itself may not provide the right answer You must scrutinize its components

Six Big Losses OEE takes into account issues like: Machine breakdowns Setup time Line restraint Reduced speeds Start-up rejects Production rejects On-machine probing addresses three of the six big losses in OEE Is the sum of those losses worth a probing cycle?

Obstacles to OEE Availability – Any event that effects planned production Changeover, setup , break downs, material shortages Performance – Any event that causes the process to run at less than optimal speed Machine wear, operator inefficiency , mis-feeds Quality – Parts that are not produced to specification and require rework Start-up scrap, production scrap Q: What are the roadblocks to world class OEE? A: Scrutinize the individual components.

Current State of Manufacturing Start-up scrap: One of the biggest losses to a production environment comes from the setup procedure . This may be because the setup process is very dependent on the skill of the operator. There is also a chance that the wrong rough stock can be loaded. Production scrap: Another major loss to a production environment comes from the production process itself (such as tool wear and features “drifting” out of tolerance). Time loss: Time is lost in production due to waiting in (off-line) inspection queues and conventional setup procedure.

Benefits of On-Machine Probing Precise Setup: With on-machine probing, setups can be located exactly to the rough stock to avoid air cuts or buried cutters in a roughing process. Process verification: Features can be inspected during the production process and reported back to the operator. This will reduce time at the CMM and allow for more uptime at the CNC. Time savings: Routines can be written that will allow setup to be performed in a fraction of the time of conventional (manual) setup procedures. Local work coordinate systems can also be used to eliminate positional accuracy of the machine for a high-tolerance, local set of features, such as bolt hole patterns.

For the sake of discussion, all of the comparisons will be done in reference to the SMPI demonstration part SMPI Demo Part

Process Steps 106.5 minutes 43.5 minutes Pre-Technology Time in minutes Tasks Why & Benefit Post-Technology Time in minutes 20.0 Set G54 Establish work coordinates 2.0 4.0 Validate rough stock Inspect for correct stock 2.0 4.0 Laser inspection face mill Accurate tool length - TCM 1.5 10.0 Face mill surface Optimized tool path - IM 5.0 4.0 Laser inspection end mill Accurate tool length - TCM 1.25 21.0 Roughing two pockets Optimized tool path - IM 10.5 8.0 Finishing two pockets Optimized tool path - IM 5.5 8.5 Set G55 & G56 Set local work coordinates 1.0 4.0 Laser inspection drill Accurate tool length -TCM 0.5 4.0 Drill holes in G55 & G56 Optimized tool path - IM 2.5 19.0 End mill roughing two bores Optimized tool path - IM 9.5 3.0 Laser inspection measure tool Accurate tool wear - TCM 1.25 1.0 Finish 50 mm holes Improved accuracy of holes - IM 1.0 varies Final inspection On-machine probing vs. CMM 3.0 Probing steps in blue

Setup Time Reduction and Quality To minimize linear inaccuracy, on-machine probing can establish a local WCS on localized datum This is more significant on longer parts with features that may be clustered in different sections of the workpiece Setting a local work coordinate system showed a 50% average improvement in the true position Time Savings: Conventional Method = 8.5 min OMP = 1.0 min  = 7.5 minutes True position improvement of 50% and more than 7 minutes saved

Setup Time Reduction and Quality A reduction in time at the CMM and an improved part quality means that there is and increase in the overall equipment effectiveness (OEE) of the plant. Unknown Distance G55 G56

Success Stories Successes from actual customers of TechSolve that have adopted the use of spindle probes

Effect on Availability One component of OEE is the lost of efficiency due to machine availability The availability is defined as: Availability = Operating Time / Planned Production Time Availability: Less trips to the CMM and less setups means that the customer is utilizing their machine tool to make more parts To achieve this the uncertainty of the process has to be addressed

Effect on Availability Scenario: A company manufactures complex aircraft components during a three shift (24 hour) operation. The components must be inspected to a traceable standard before they can be signed-off. The queue at the CMM and the inspection process is one hour. The CNC must idle while the inspection is taking place or risk making scrap parts. Solution: After tuning the machine and performing repeatability studies on the machine, the CNC can inspect the parts with a high level of certainty per ASME B5.54. The shop is able to move from lot inspections to first and last article inspection while sampling CTQ features on the CNC. The availability of the machine increases by 12%, which adds to the OEE due to the increase operating time. Availability = Operating Time / Planned Production Time

Effect on Quality & Availability Problem: A customer has to machine a cast aluminum housing. The housing has two production locating pins that are used as datums that span 24 inches apart. Between those datums are a series of machine features, among those features are four bored holes surrounded by bolt hole patterns that have to maintain true positions of 0.040”. Solution: The client is able to use a spindle probe to establish a local work coordinate system within the bore diameter. By using that local work coordinate system as the origin of the bolt hole pattern, the process is able to easily hold a true position of 0.001” (previously 0.040”) to the main bore without breaking the setup or making multiple trips to the CMM.

Effect on Quality and Availability Quality: The customer realized a 60% increase in the part quality from the use of the spindle probe Availability: Less trips to the CMM and less setups meant that the customer is utilizing their machine tool to make more parts

Effect on Quality Problem: A manufacturer has an issue with bottlenecks at the inspection area due to the volume of work being produced on the CNC machining area. Goal: To utilize on-machine probing to go from ongoing inspection to first article inspection, which would reduce the inspection time by 80%. This would lead to an increase in production due to less time spent waiting for inspection . Cell #1 Cell #2 Cell #3 Inspection

Effect on Quality Solution: The biggest concerns from the quality department was being able to Produce parts that were statistically within control for sampling Have a method in place to make sure that the machine tool was qualified The machine tool was first qualified and tuned to reduce metrology errors Repeatability studies were performed per the ASME B5.54 standards to ensure the quality of the probe itself The CNC machine was “foot-printed” using a diamond-circle-square test and the part was collaborated using a traceable CMM

Effect on Quality Result: With a machine that is qualified, repeatable, and traceable the customer can now inspect parts on the machine within a relative certainty This will result in an a single daily inspection on the CMM and ongoing inspection key features on the machine This increase in part quality and throughput will have a direct impact on the plant’s OEE because of the reduction in the three of the six big losses: Start-up scrap Production scrap Waiting for the CMM’s approval throughout the day

Conclusion Spindle probes are meant to increase the productivity and the effectiveness of a process Probing offsets the time and cost of scrap and downtime that is currently in the machining process Reduction in scrap and reduced time spent performing offline inspections will increase the overall equipment effectiveness (OEE) of the process

Questions? For more information see TechSolve at booth # 1022 Moise Cummings (513) 948-2048 [email_address] www.techsolve.org

Amts Presentation

More Related Content

What's hot (20)

Similar to Amts Presentation (20)

Recently uploaded (20)

Amts Presentation