Some time ago, I saw a post saying that after doing a batch of work, the diameter was 69.5, but it was scrapped. The customer said that the diameter was half as small. We also all know that if Party A is in a hurry for this kind of workpiece, once it is reworked, it is likely to affect the processing progress of Party A's company, and if it goes wrong, it will pay millions in breach of contract.
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After receiving the news, other people in the company immediately began to calculate, and various results were obtained. The scene at that time was really like an ant on the hot pot. Fortunately, one of the colleagues saw it and said that the standard method was wrong. Generally, symmetrical workpieces should be marked with a taper, so the markings on this drawing are not very standard. The converted angle of a slope of 1:10 is approximately 5°42'38", which means that the horizontal distance advances by 10 units and the vertical distance rises by 1 unit, which is the angle. The tangent value of is 1/10, and the angle can be calculated using arctg0.1.
After reading this post, I remembered that when I first entered the factory, the master always asked me to mark the angles on the drawings, because many times I am used to marking the length and two diameters and that's it. Every time this happens In this case, the master taught me not to correct the angle. When I saw this post today, I suddenly felt that the master had really good intentions. If only the angles were marked on this drawing, there would not have been such a big loss.
In fact, many factory workers just work. There is nothing wrong with the labeling in this picture. It's just that the workers don't have a thorough understanding of the uncommon symbols. Without marking the angles, the workers just do the work according to common understanding. Even at first glance, I thought the drawings were based on SIN values, but they turned out to be TAN values, so you must not be careless when looking at the drawings! careless! careless!
In addition, the company's design is very lax, and the drawing reviewers for machining are also very lax. If this kind of work requires taper turning, standard dimensions and angles should be specified in detail. Those factories in the workshop do not have computers available, and their workshop processing personnel are not familiar with Sometimes they don't even bother to calculate the size of the chamfer.
I remember that a friend once did a lot of work. He converted foreign drawings into something that everyone could understand. It didn't matter what the number was, just ×25.4. But there is a roughness, because the drawing is very dirty and not very clear. One of the standards is 125, so they defaulted to 12.5, and they did it according to 12.5. As a result, the customer paid the full price, and 125 corresponds to the national standard 3.2.
This kind of redundant work is a trivial matter. If the delay in delivery is seriously delayed, Party A will have to pay a huge amount of breach of contract. It may also lose customers and easily create a bad reputation in the circle. It can be said that it is not worth the loss.
Therefore, if you work in our machinery industry, you should always be cautious! cautious! Be more cautious! Because the design and drawing resulted in mistakes, the loss of money is a small matter, but being sentenced to prison is really more than worth the gain. Don't think it is just talk.
As a designer, you must be rigorous: try to strictly follow the drawing standards, think more about the workshop processing personnel, try to be clear and concise, and send more 3D drawings to Party B, so as to avoid the possibility of errors.
As a processor: Don't be sloppy when looking at pictures, be sure to ask questions when you are unsure, and don't be too troublesome. If you don't understand the markings on the drawings, you cannot blindly process them, otherwise they will be scrapped in batches. Don't start work without confirming the specifications. Don't be lazy even if it's troublesome in the early stage. Even if you start work, you must have samples. Don't be so confident that you can finish a batch of work without samples.
