Spring drawing mistakes are very common when you talk with the factory. It just doesn’t go smooth as we expected.
Imagine this situation, when you inquire a spring factory with the drawing from engineers. The factory continually asks you for confirmation on the spring drawing mistakes, mostly in partial sizes, angles, number of coils, etc. You take the question back to the engineer. But the engineer just suggests you do as per the drawing. Suddenly you get messed in how you should talk with the factory and engineer. You are purchasers. It’s worthless to waste time on the communication of spring sizes. So, you choose to change another factory to start it again…
But how does this come out? It’s not an effective way and it’s miserable in the continuous inquiry.
To solve this, you need to understand the problem in this procedure. Follow our instruction below, maybe you can learn something from it.
Since the force type is different, so the structure of springs is different. We summarize some common spring drawing mistakes we met in our daily work. We will analyze them respectively according to different spring types.
1. Measuring Mistakes
It’s a very common mistake. This situation mostly happens as the customer is not an expert in engineering. You always can’t provide a drawing, so you measure the sizes by yourselves via a sample. In this procedure, there are three common mistakes to influence the spring drawing.
A. You don’t choose the right measuring tool. We suggest caliper to measure any size of springs, NOT TAPE MEASURE.
B. You measure the wrong position of the spring. Or the method of specific sizes measuring is wrong.
For example, if you measure the outer diameter for a compression spring drawing, you need to take the caliper vertically to the spring. Many customers measure the outer diameter horizontally to the spring. It will cause inaccurate sizes due to the tolerance of each coil.
C. Sometimes, you forget to measure all sizes. Springs coils are often variable, we need to measure all coils and sizes.
And we highly suggest a qualified sample instead of a used sample. Because the used sample sizes probably have changed a little bit. This will lead to inaccurate result.
2. Measuring sizes are not conformity in unit of measurement.
It happens more on small companies. The engineer may be careless to mark all sizes in the same unit of measurement in the drawing.
3. Torsion spring drawing mistakes
Torsion spring has angles and bends. Many customers only provide sizes for the torsion spring, but they forget the angles. Angles is the most common mistake in torsion spring drawing.
4. Tension spring drawing mistakes
The common mistake on hooks and initial tension force. Tension spring hook has a diameter and open part. It’s necessary to mark the diameter of the hook and size of the open part.
Another issue is the initial tension force, it’s critical for the tension spring performance.
5. Compression Spring Drawing Mistakes
Many engineers will ignore this mistake. That is assembling axis diameter and assembling hole diameter. We used to make a batch of springs for a European customer. When the cargo arrived, they found that it can’t be assembled to the axis. Because the spring inner diameter is smaller than the axis diameter. But we do exactly as the drawing.
There are many different mistakes in spring drawing. We listed just some common ones. Every factory will take the customer’s drawing seriously. If they are questioning the spring drawing, there must be some issues on it. Please work on it together to find it out and get it manufactured.