Shop Talk with Steve Rose,
appearing in Tooling and Production
Shop Talk with Steve Rose,
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Always looking to improve productivity and efficiency, many companies are talking about unmanned machining. Sounds great, you set the machine to run all night, turn out the lights and go home.
Unfortunately, unmanned or lights-out machining is not as easy as it sounds. Unmanned or more accurately, minimally manned machining may be a serious goal for many companies, but a detailed analysis should be conducted first.
In many cases, new technology is used to monitor machining conditions, which are normally watched by human operators. Often, unmanned machining means replacing labor costs with capital expenditures.
The benefits of these types of expenditures may not result in a quick payback. There are also risks associated with minimally manned machining and new technology. Therefore, minimally manned machining should be carefully reviewed before being implemented.
To conduct a thorough review, you should be familiar with the latest technology, including tool monitoring systems, fire suppression systems, power monitors, part gauging techniques, replacement tooling systems, bar feed machines and multi pallet pools.
Let’s review a few of these systems, judge for yourself if investments in these tools benefit your machining operation.
Before letting your machine run on its own, you may want a tool monitoring system. Imagine setting up your bar-fed lathe, you want to leave it running from 6 PM 11 PM to machine a few more parts before the end of the day. The turning tools, drill and tap are all set. You leave it running when you go home at 6 PM. At 8 PM the drill breaks. What happens then? Well, first thing, the tap breaks because the drill didn’t do its job. Then, the machine continues to process parts, but they are scrap parts. Imagine the costs of 3 hours worth of scrap.
This situation may be avoided with a tool monitoring system. One such system is the ATAM Machine Monitoring System, from ATAM Systems, Inc. (Columbus, Ohio).
ATAM Systems provides a wide variety of machining feedback tools from crash detection to tool monitoring. The crash protection feature can reduce major crashes due to set up problems caused by an incorrect G54 style workshift value or by a part that was loaded incorrectly.
We have all seen crashes due to simple mistakes that can result in costly damage. The monitor limits machine damage as the machine automatically stops once the load has exceeded normal limits.
Another time and cost-saving system is the ATAM tool monitoring unit. This can be a powerful tool in any manufacturing operation. The ability to prevent tool breakage, monitor tool wear and part fixturing can be quite valuable.
The ATAM unit electronically monitors and measures machining conditions. Comparing the conditions with acceptable ranges for these systems, the ATAM unit provides feedback on the machining activity. A "power profile" is defined for each tool, the system monitors the various loads on the tools when cutting in a new slate.
The profile of cutting tool forces is clearly shown on a P.C. unit. Once we have a power profile of our machining method we can monitor the wear condition. Care must be used to establish the action limits for each particular tool. This takes greater involvement than just utilizing the crash protection system.
The system is also useful in developing efficient cutting conditions. As we use the power profile we can compare different tool geometry’s, cutting conditions (speeds and feeds) and evaluate different types of material for machining characteristics.
If a tool breaks, the machine shuts itself off, avoiding endless scrapped parts and additional broken tools. ATAM provides a variety of monitoring system, with various features from simple crash monitoring to tool wear protection.
The feedback from these units can be impresssive. Analysis of all the data can lead to precise manufacturing conditions, accurate tooling use and costs, minimal down-time and long term efficient manufacturing.
Monitoring systems such as these vary in level of service and in pricing. Basic systems can range from $4,000 for simple crash protection to over $15,000 for a full-blown multi-channel system. This type of expenditure may not be easy for small shops looking to improve their productivity, but it is part of a strategy to increase production while maintaining labor levels.
Tool monitoring systems are only one aspect of developing a minimally manned machine shop. Next month, we’ll review other products and technology that can make "lights-out" machining a reality.