El blog de los útiles de control y la metrología

Following with the subject treated in the latest articles about The Checking Fixtures´ Ennemies, we will now deepen the second most important aspect to be taken into account.

Our experience through a lot of years has shown us that there are three types of part manufacturers that could be classified according to their idea of “checking fixtures”: (i) the first type of manufacturer is absolutely convinced of the fact that checking fixtures, gauges and measuring tools are an essential factor in all the production chain to get the quality level demanded by his customers ; (ii) the second type of manufacturer purchases checking fixtures, but more because it is one of the final customer requirements than for its own convictions, as if it were a mere step in the production process ; (iii) finally, the third type of manufacturer does not use checking fixtures at all as a prevention checking tool. He only purchases checking fixtures once a problem has appeared and he has to deal with a problematic solution he does not know how to fix.

Such different visions of “checking fixtures” are obviously related to the “quality check” policy that each company can have. A mere overview of the equipments, metrology and measuring tools used is enough to conclude that sometimes, there are abysmal differences.

Of course, it is not always possible to be in the situation of the Group (i) manufacturers, and that each company, considering its resources, economic situation, and specific circumstances will have to set its “quality check” accordingly. The aim of this article, however, is to make you think about the fact that the “checking fixture” is, in a lot of occasions, underestimated. For a lot of people, it is no more than an expense increasing the price of the product; yet, if things are done well and it is given the importance it should really have, it will, on the contrary, not only enable to save a lot of money and time to fix problems that could have been avoided (“prevention is better than cure”), but also have a direct influence on the quality of the product.

Often, group (ii) manufacturers wrongly regard checking fixtures as a mere formality. An initial lack of concreteness of the checking fixture (be it when sending the quotation to the final customer or when setting practical aspects with the checking fixture manufacturer) triggers many times an accumulation of mistakes difficult to fix. This lack of concreteness, as well as last minute emergencies and modifications can be avoided if, as soon as the beginning, the checking fixture is given the importance and fondamental role it should have in the whole manufacturing process. We are convinced of the fact that if these companies change their vision of checking fixtures and begin to regard them differently, by giving them the importance they should have, then “checking fixtures” will make them save time and money, and they will stop to see them as an “expense” to see them as an “added value”. Believe me, the effort is worthwhile.

As for Group (iii) manufacturers – in which are still too many companies – there is still a long way to go. These companies are not aware yet of the fact that quality problems have negative consequences, be it, obviously, on the very product, or on the organisation, working atmosphere, and stress that will end up weakening all the levels of the organisation, from production to quality or business… Problems get piled up, preventing them from having a clear vision of the situation, solutions are choosen hastily, nearly without thinking, and all this spiral lead them to failure. Although it does not seem to be true, I have lived through situations of real chaos that could have been fixed very easily if, initially, the suitable measures had been taken. These companies must be convinced to give an opportunity to the “checking fixture” so that they will gradually get closer to the Group (i) companies, whose characteristics regarding their quality policy are described bellow.

This Group (i) companies are characterised by the following points:

• • They have staff and premises exclusively dedicated to quality checking.
  • They have technicians with experience in that type of tools and metrology, that dedicate themselves from the very beginning to the awarding of the project for the production of gauges and checking fixtures. They carry out the follow up of the project.
  • They consider that an economic part must defended to be able to be provided with the necessary gauges.
  • They always try to get the minimum checking means to deal with potential risks (SWOT) during each part manufacturing.
  • They make sure to have the suitable checking means before having at disposal the production means, in order to be able to check the first parts manufactured.
  • They prepare specific technical specifications for every checking fixture, which are analysed in detail to get as much profit from the investment realised and are previously approved by the final customer to avoid further modifications.
  • Finally, they do not forget either to make a correct maintenance and regular calibrations, while making sure that the production staff always have at their disposal user manuals to use correctly their checking fixtures.
  • They are sure of the cost each checking fixture will have, and if they do not have any budget available, they have time to make a careful search among their ranges of providers to get it as cheap as possible.
    

This is an important effort, but on the long term it is worthwhile and the results are visible. A badly designed checking fixture will end up in a disaster. The lack of definition and concreteness for the details is usually the main reason of this failure. Nobody knows better than their manufacturer the parts problematic, aspects to check and things that must be avoided; so, the project will be a failure if he does not get involved in it. An investment of time “on time” can save a lot of money.

We sometimes hear the following sentences: “Just decide it, you are the checking fixtures expert”, “… but have not you made other similar checking fixtures for other customers?”, or “You have already made checking fixtures for similar parts for us” - when the part has had significant changes compared to the past versions -. And in some cases they do not even have the information necessary to design correctly the checking fixture.

To take decisions, we will need to have a plan indicating us the isostatisms, critical dimensions as well as their tolerances, etc… and the latest update of the 3D file. Consequently, if we do not have this information at the beginning, then it is impossible to make a correct work.

We would like to hear less often these sentences. The manufacturer must be treated with the respect he deserves, but he has to value our work as well. We all have to be involved in the project, this is the only way to get a satisfying result.

We will always repeat it, the checking fixture must not be underestimated any longer and must be given the importance it deserves. We are convinced of all this, and this is why we will continue our work and give the best service and quality to our customers, while being sure that throughout time the group (ii) companies will get closer to the group (i) ones, and hoping that the group (iii) companies will sooner or later give to checking fixtures the opportunity they deserves.

Related articles: The Checking Fixtures´Ennemies, A Low Budget: Ennemy #1

Photography: Stockxpert