If we consider the manufacturing of extension springs as a manual process, which isn't the usual case here at Transworld Engineering of course, it is easier to highlight the differences between the manufactured level of tension in an extension spring, and the typical and reasonable operating tension.
In the manufacture of an extension spring, there are things that we need to consider. One of these is the initial tension of the extension springs and how it relates to the working tension of the springs in their daily uses. The probability of there being a difference is high. The loops at the end of your spring’s end may or may not cross or line up with each other. Where your spring is long enough, you can opt to twists these loops to make them cross or align with each other. They will remain held in that position due to the initial tension.
It is essential to assume the loop position.
Below, we are going to discuss the process of making a basic type of loop that has no frills and will work with most springs. You can make other types of spring loops that are stronger, more efficient, and prettier. However, there are specific tools that you must have for you to make these types of loops.
1. Cut and get rid of the spring’s end. It is crucial as you will leave the coils that are in contact with each other all the way around.
2. Mount and firmly your spring in a vice between the two looping plates.
3. Using your looping rod, reach into the spring’s centre and hook your rod’s tip under the first coil.
4. Push the rod downwards to apply pressure that will bend the rod upwards. Let go of the rod when the coil top is directly above the spring’s centre.
5. Reach under the already bent coil using a looping rod and using the tip’s rod, snag up the end of the wire.
6. To align the coil’s end with the spring’s body, apply pressure to bend it.
After performing this procedure, you will have made one end of the spring. The next step in creating a simple loop is figuring out the length of wire that you need to get rid of on the other end to achieve the desired length. If you wish to make it a little short, extend your hooks. All you need to do is straighten out the wire once you take it off the body of your spring.
Where you aim to make just one short spring from your coil, count the coils you have and depending on the number you need, add or remove to remain with the number of coils you need. If you have wound a long coil when you are making a short spring, repeat the same thing. Using your wire cutters (or a cut-off-wheel where you are working with a heavier wire), from the main body, detach the first spring.
Cut off some parts of the whole coil for you to achieve the right length. However, keep in mind that you are only needed to add to each end of spring “just shy of a full coil” for you to achieve a high-quality product.
Alternatively, where you have a long spring (or where you do not wish to waste your time counting the number of coils), all you need to do is measure the coil’s body and make an addition of about 1 coil.
Once you trim the body of the coil to size, proceed to make the second loop. The procedure for making the second loop is similar to that of making the first loop. To ascertain if you have come up with the desired length of, double-check the spring inside one hook to the inside of the other. Checking in this manner allows you to get the best and accurate results.
Where the length of the spring you have made is very short, there are several options for you to correct it. You can choose to either make the next spring with a fancier loop type or with more coils.
For most extension springs, loops are the most convenient and ideal. However, there are times that you will need to use hooks for efficiency. For instance, you need to use a hook when you want to slip your spring onto a pin.
There are times where hooks that swivel are ideal for making extension springs, but if you do not have kick press tooling, it is a challenging task. For you to be on the safer side, ensure you purchase a commercially made one.