How to make a self-made spring dynamometer

Spring dynamometer is a commonly used force measuring tool, which is suitable for measuring tiny force. Its main principle is to use the deformation of the spring to measure the tension or pressure on the object. Self-made spring dynamometer needs some basic materials and tools. This paper will introduce how to prepare materials, make parts and assemble dynamometer in turn.

Preparation materials:

1. spring wire: this is the main material for making spring dynamometer. Spring wire with a diameter of about 0.5- 1mm can be bought in the market, and the material can be stainless steel, brass, iron, etc.

2. Bamboo stick or thin wooden stick: used as a pressure bar for self-made spring dynamometer.

3. Elastic ring: This is a ring made of hard paper or other elastic materials, which is used to fix the spring.

4. Plate: used to make the base and side plate of self-made spring dynamometer.

5. Metal screws: used to fix parts.

Manufacturing parts:

1. To make a spring: first erect the spring wire, and then clamp it at both ends with pliers. Then another spring wire is wound 4-5 times along the center of the spring wire to make the spring form an Ω shape.

2. Making a compression bar: Cut out bamboo sticks or thin wooden sticks with scissors of appropriate length, making them slightly longer than the spring, so as to be easy to hold when using.

3. Making elastic rings: Cut cardboard or other elastic materials into disks with appropriate size, which is similar to the diameter of the spring. Next, drill a small hole in the center of the disc to ensure that the spring wire can be accommodated.

4. Manufacture of bottom plate and side plate: cut the plate into the materials of bottom plate and side plate, and reserve a circular outlet on the base for the dynamometer to connect with the measured object.

Assembling dynamometer:

1. Fix the elastic ring: put the elastic ring in the center of the spring, and carefully pass both ends of the spring through the holes of the elastic ring respectively. Then fix both ends of the spring. After fixing, the elastic ring can be pushed up a little, so that the bamboo stick or thin wooden stick under the spring is slightly bent, which is convenient for operation.

2. Fix the side plate: fix the side plate on one side of the base, drill a small hole near the edge of the base, and observe the expansion and contraction of the spring through a bamboo stick.

3. Fixing the compression bar: fix one end on the bottom plate, and then put the other end of the bamboo stick or the thin wooden stick into the bent part (Ω shape) at the top of the spring and fix it.

4. Test dynamometer: Put the self-made spring dynamometer on the test object, and press the pressure bar at the top, and the spring will be deformed. The position of the pressure bar can be observed by using the small hole in the side plate, so as to determine the force on the measured object.

The above is the making method of self-made spring dynamometer. Special attention should be paid to avoid damaging the spring wire by excessive force in the manufacturing process to ensure the accuracy of the test results.