|Schleuniger CrimpCenter 64 is a fully automatic machine that cuts, strips and crimps. |
In the past, it was typical to see production batch sizes for automatic termination machines between 1000 and 5000 pieces or more. Most companies would simply make a large batch of parts and stock the parts until they were needed. Because of lean manufacturing and JIT production practices, the production environment and demands today are much different. Now, a large batch size would be 200 to 500 pieces. Some companies have an average batch size of 50 pieces or less.
Many companies plan well, but they are not good at preparing the next job. If all of the materials were available to the operator, machine changes, even on older machines, could take between 5 and 10 minutes. However, we often see setup changes take 30 or 40 minutes because the operator has to go search for materials. Meanwhile, the machine is sitting idle on the production floor. The most efficient companies have a system whereby the materials are gathered and brought to the machine before the job needs to be run. This type of process may require an additional person or two, but if the machines are being changed 20 or 30 times a day, the additional machine utilization may pay for the additional person faster than you think.
All too often we see operators and technicians making applicator adjustments on the machine. How much downtime could be eliminated if your operators did not have to make any adjustments to the applicator on the machines? The most efficient companies have a dedicated tooling area where applicators are setup and inspected before jobs. Crimp height and pull test are verified for the given application. When the applicator goes to the production floor, it is ready to run. This applies to automatic machines and benchtop crimping presses as well.
For this concept to work, all of the crimping presses would need to be calibrated to have identical shut heights. Many presses today have electronic crimp height control. Regardless, the press shut height should be calibrated to a standard. The most common standard for press shut height is 5.346-in. (135.78mm). Whether you use this value or not, the shut height dimension should be the same on all presses. If they are, the tooling area can set up the applicator, and when it is moved to another press, the same crimp height values are achieved.
Another consideration for applicators is compatibility with crimp force monitors. Many customers who are not familiar with crimp monitors overlook applicator quality. If an applicator or the tooling is not in good condition, the result may be excessive variation in the crimp force curves. Therefore, the monitor might give erroneous good/bad signals to the machine based on a worn applicator and not on the quality of the crimp. A dedicated tooling area could also evaluate the condition of each applicator and the tooling after it came off the production floor. Just this tip alone can save countless hours of down time when working with crimp force monitors.
As most of us know, the most difficult wire to work with is curly or non-concentric wire when working with any automatic machine. The machines are designed around the assumption that the wire will be relatively straight and concentric. Curly wire effects both wire feeding and termination (e.g. crimp, tin, seal, etc.), and non-concentric wire obviously makes it difficult to strip properly. Some companies may attempt to save money by purchasing less expensive wire. Sometimes a lower price means lower quality and lower quality can result in lower productivity. Non-concentric wires will only reduce productivity because extra quality checks may be required. So depending on the specific situation, lower cost wire may increase production costs by increasing downtime.
When working with automatic machines, barreled wire is always preferred over spooled wire because spooled wire has more curl. This is especially true with spools with small inner cores and when the wire gets toward the end of a spool. Try consistently terminating with closed barrel terminals with curly wire. Forget it. Barreled wire is typically much straighter and much easier to work with. Spooled wire also usually requires a prefeed. Prefeed units may help with the memory, but the threading and unthreading of them during job setup always takes more time. Furthermore, most prefeeding units will require reduced feed rates on the automatic termination machines because the prefeed can not keep up. Therefore, most prefeed units reduce productivity on automatic termination machines. There are always exceptions to the rule and some barreled wire can be very curly. This can happen because of the insulation type and wire quality. If you do have curly, barreled wire, speak with your vendor to determine if the quality can be improved.
Your company is investing considerable amounts of money on a new machine to improve productivity. In some cases, it may be necessary to invest a little more for higher quality materials so that the new machine can reach maximum productivity and the ROI is maximized as well.
The optimal location for the QA devices is on the machine. The reason is simply to reduce the amount of time required to either walk over to the QA station or find the QA inspector. Also, if the QA devices can be integrated into the machine, the machine can be preprogrammed with the nominal test values and tolerances so the operators can perform the tests quickly and efficiently. They will not need to leave the machine, they will not need to search for the specifications and there is less room for errors. QA will also have tighter control over the tests by removing any operator judgment during the test.
Without regular preventive maintenance (PM), machines can not be as efficient as when they were new. The most important and the easiest PM is regular cleaning. This can be achieved by simply having the operator take 10 minutes at the end of each shift to clean the machine. The best way to clean any machine is with a vacuum. Although compressed air is most commonly used, it can blow debris into areas where it shouldn't be.
Every machine will come with a recommended PM program. However, it may be necessary to customize a program based on the environment the machine is in and the applications that are being run on the machine. For instance, is your production area generally very clean or is it very dirty and dusty? Furthermore, tinning applications require much more PM than simple crimping applications.
PM programs can be purchased from most manufacturers. Periodic reviews and calibrations by qualified technicians will keep your machine in top performance and make potential problems known before major problems occur. The additional expense of a good vendor PM program can save you a lot of money in the future.
For more information, contact: Schleuniger, 87 Colin Dr., Manchester, NH 03103 603-668-8117 fax: 603-668-8119 Web: http://www.schleuniger-na.com