What is a mechanical poker vibrator, and what benefits does it offer?

In my last BLOG post, we answered the question: ‘What is a poker vibrator?’, and mentioned that there are several different types of poker vibrator tips. Although the various types generally function the same way, there are still differences that affect the function or use of each type of poker vibrator. In this week’s BLOG post, I’ll talk about the mechanical poker vibrator, its advantages and its disadvantages.

What is a mechanical poker vibrator?

As we explained in the previous BLOG, a mechanical poker vibrator is a poker vibrator that uses a mechanical cable to connect the motor to the vibrator mechanism. This cable is fitted inside a flexible rubber hose, so the vibrator tip can be used around corners.

Afbeelding 1, de mechansche snaar in het groen weergegeven in de rubberslang in 1 meter P14E.

What are the benefits of a mechanical poker vibrator?

One major benefit of the mechanical poker vibrator is the simplicity of the tool. A properly functioning mechanical poker vibrator only needs a drive unit, a cable and a vibrating mechanism. This limits the number of poker vibrator components, which makes the machine relatively easy to repair.

Mechanical poker vibrators with portable electric drive units and short hoses are also referred to as ‘hand-held poker vibrators’. These are extremely lightweight, and usually need only a standard 230V power outlet.

The hand-held poker vibrator was developed from the conventional poker vibrator, which uses a much longer 7-meter rubber hose that houses the mechanical drive cable. Its length and the weight of the cable requires a much larger drive unit. These are often so large that the drive unit cannot be moved by a single person, and requires a 3-4 man pour team to compact the concrete using the 7-meter tip and drive unit.

Voorbeeld van mechanische trilnaalden

Despite its size, the conventional mechanical poker vibrator is still the most commonly used poker vibrator around the world, especially in Africa, Asia and South America.

The large number of machines and parts available mean that they are usually inexpensive to buy, and users are accustomed to the relatively frequent maintenance intervals and high maintenance costs.

 

In the West, however, the conventional poker vibrator is less common. Here, builders prefer to use the hand-held mechanical poker vibrator due to its advantages over the conventional version. A hand-held poker vibrator:

  • needs fewer people to do the same amount of work;
  • is faster, safer, and more ergonomic in use;
  • provides a better return on investment if the total costs of the machine (purchase and maintenance over the full service life) are included.

 

Disadvantages of a mechanical poker vibrator

The simplicity of the mechanical poker vibrator is also one of its disadvantages in real-world use. The mechanical spring is subject to considerable wear, which increases along with the length of the vibrator mechanism and higher RPMs, due to the friction between the cable and the inside of the rubber hose. This causes frequent cable breakages, and therefore frequent repairs. The entire cable will have to be replaced.

As the amount of wear depends largely on the length of the hose, a hand-held poker vibrator will be much less likely to break down than a conventional mechanical poker vibrator. However, both machines have to use the same vibration frequency, as they have to compact the same concrete. Most poker vibrators vibrate at around 12,000 Hertz, which is the best frequency range for compacting most concrete.

The vibration mechanism inside the tip provides the vibrations necessary for the tool to do its job. Mechanical poker vibrators use one of two types of vibration mechanisms: rotating or pendulum systems. I’ll talk about the differences between the two in my next BLOG post.