How to Repair a Flexible Trimmer Shaft

A flexible shaft, the main purpose of which is to transmit torque over a considerable distance, is most often used to equip engravers. Such equipment, which, in fact, is a miniature grinding machine, is actively used to process small parts. In particular, the engraver is used as a mini drill, with its help they perform miniature cutting, selective grinding of small elements of products and a whole list of other works.

Flexible shaft simplifies the use of the engraver, eliminating the need to hold the tool over the workplace

The most common areas in which engravers with a flexible shaft mounted on them are used are jewelry and the electronics industry. Designers, employees of car repair stations and workshops involved in the repair of household appliances and electronic equipment are actively using such equipment.

The electric engraver on which the flexible drive is mounted is especially relevant in situations where processing must be performed in hard-to-reach areas of the product. Using interchangeable nozzles, such equipment can be used at all stages of the processing, starting with the draft and ending with the finish.

Flexible engraver shaft with protective springs at the ends, protecting the rubber sheath from damage

What operations are done with a flexible engraver

To turn the engraver with the flexible shaft mounted on it into a truly universal device, special nozzles help, which include:

  • grinding and polishing wheels, allowing to bring the surface of the workpiece to a perfectly smooth state;
  • brushes used to clean the surface of the product and polish it in hard-to-reach places;
  • cutting wheels for cutting products and processing their ragged edges;
  • drills, with which the device turns into a miniature drill;
  • milling cutters and abrasive wheels, allowing the processing of products in hard-to-reach places;
  • pen-shaped nozzles with which engraving work is performed.

To ensure the convenience of working with such a device equipped with a flexible drive shaft, you can purchase additional devices. rubber pads on the handle, the latch of the power button, etc.

All kinds of holders are very useful, in which, in addition to the shaft and the engraver, various nozzles can be fixed

Engravers on which a flexible drive shaft is installed also include a drill used in dentistry, a manicure machine, equipment for processing natural stone and applying inscriptions and drawings to the surface of products made from it.

You can also use a flexible shaft for a drill or purchase a flexible shaft for a screwdriver. With this improvement in conventional power tools, a screwdriver head or drill can be successfully used to carry out work even in the most inaccessible places.

How the engraver works and by what principle

The engraver, which allows you to process parts with high precision and performance, works on the principle of a conventional drill, and externally it is very similar to a large automatic handle. The main structural elements of such a device are:

  1. engine;
  2. flexible drive shaft transmitting torque from the engine to the working nozzle;
  3. gearbox;
  4. fan for cooling the spindle;
  5. spindle itself with a protruding working part;
  6. device case with special openings for the exit of heated air;
  7. a nut designed to fix used nozzles;
  8. device power regulator;
  9. lock button;
  10. power switch;
  11. hook for hanging off the device.

Equipment Selection Criteria

When choosing an engraver should focus on a number of characteristics.

By the power level of the device, on which its performance directly depends, one can indirectly judge the working resource of the drive motor. Choosing the power of the engraver, which for serial models can be in the range of 35–300 W, should be based on the tasks for which it is planned to use such equipment. In addition, you need to consider how long it will work between on and off. The duration of the operating process depends on the hardness of the material from which the workpiece is made. The longer the engraver will be used for one inclusion, the more power it should have.

The low-power compact engraver is convenient for simple work without a flexible drive

The speed at which the motor shaft and the flexible drive shaft attached to it rotate are also selected depending on the hardness of the materials to be processed using an engraver. Models offered on the modern market can provide tool rotation speeds in the range of 10–35 thousand rpm. Low-speed models can be purchased if they are used primarily for finishing grinding and polishing. When performing such operations, the tool has a small load, so the engraver itself does not overheat, which means it does not fail.

Video: How to Repair a Flexible Trimmer Shaft

Speed ​​control significantly increases the engraver’s functionality

The weight and dimensions of the engraver affect how convenient and easy it will be to manipulate such a device during processing with its help. Engravers who differ in significant dimensions and weight are much harder to work with, but such devices, as a rule, have higher power and productivity. The weight of the engraver with a flexible drive shaft can be in the range of 0.5–8.5 kg. Choosing such a device, first of all, take into account the required power and functionality, and only then pay attention to weight and dimensions.

Since the engraver is working, constantly holding such a device in their hands, its ergonomics, which characterizes the convenience of working with equipment, is an important factor when choosing. Estimating the ergonomics of the device, one should pay attention not only to its design, but also to the build quality, workmanship, button layout and the convenience of the handle design.

Before acquiring a tool, you should hold the engraver in your hands, test the inclusion of buttons and clips

These parameters are not indicated in the equipment passport. It is advisable to pay attention to them if the engraver will be used often enough. To evaluate how much the device makes noise and vibrates during operation, you just need to turn it on and evaluate these parameters. As a rule, engravers of medium power are more noisy, and in more resourceful equipment this problem is provided by manufacturers and is eliminated by the inclusion of special elements in the design. It is possible to evaluate how much an engraver equipped with a flexible drive shaft is heated only during operation.

Flexible shaft design

A flexible shaft for an engraver or any other equipment whose torsional stiffness is subject to higher requirements than bending stiffness, as mentioned above, is used to transmit torque to elements that change their spatial position during operation.

The main part of the flexible shaft, which is responsible for the main function of such a device, can be a wire rod or a special cable. This element is made of materials with high torsional rigidity. Additional layers of twisted wire are wound around the main core of the wire flexible shaft to give it higher rigidity. To ensure the safety of using a flexible drive shaft, as well as to protect its surface from damage and to keep lubrication on it, this device is placed in a flexible protective shell, which is stationary with respect to the rotating core.

This flexible shaft is equipped with a nozzle holder on one side and a flare nut on the other for fixing to the engraver

Depending on the design, the flexible shafts can be of right or left rotation, which should be considered when choosing and using them. Not only the design of flexible shafts can be different, but also their length, sometimes reaching five meters.

The design of the fixture of such a device depends on where the flexible shaft is installed. on a drill, engraver or screwdriver. So, fixing nuts or other type of mounting hardware may be placed at the ends of the shaft.

The tip of this shaft can be removed for cleaning and lubrication, for which a hole is provided on the side

Using flexible shafts of various designs, various mechanisms and equipment are driven. In addition to engravers, drills and screwdrivers, deep vibrators, lawn mowers and many other types of technical devices are equipped with such shafts. The simplest and most familiar option for using a flexible shaft is to clean the sewer pipes from internal blockages.

Mechanical vehicle speedometers are also driven by a flexible shaft.
Making a flexible shaft with your own hands, of course, is possible, but, given the load under which such a device works, it is better not to experiment and purchase serial production from trusted manufacturers. One can be puzzled by the independent production of a flexible shaft only if it is used to drive low-power equipment operating at low speeds.

Rules for working with an engraver equipped with a flexible shaft

There are a number of rules that should be followed when using an engraver with a flexible shaft for processing various materials.

What you need to do before you get started

Before starting work, choose nozzles. All of them should be at hand so that you don’t waste time searching for them later. While the device is in the off state, it is better to hang it on a special hook that comes with most modern models.

It is possible to prevent the adhesion of chips generated during processing to the surface of the tool if it is preliminarily coated with a layer of paraffin. It should be borne in mind: if the design of the instrument does not provide for forced ventilation, you can work with it for no more than 15–25 minutes, and then you need to give it time for natural cooling. By doing so, you will protect your engraver from premature failure.

Holding the engraver with your hands, you must try not to cover the ventilation slots with your palms

It is necessary to change the speed with which the tool of an engraver equipped with a flexible shaft rotates when changing the operations performed and when switching to processing another material. At low speeds, they process softer materials, such as, for example, plastic. If you process such materials at high speeds, this can lead to intense heating of the tool and fusion of the edges of the workpiece. At medium speeds, metal products are processed, at high speeds. from solid natural stone.

How to care for the engraver

Like any other technical device, an engraver equipped with a flexible drive shaft needs proper care. Properly and regularly performed, such care will not only allow the device to be used at its maximum power, but also significantly extend the period of its trouble-free operation.

In the process of processing carried out using an engraver, its fan blades are actively clogged with dust and small particles of waste material. In order for such a fan to work efficiently, it must be cleaned regularly using a soft cloth dipped in soapy water. In no case should you use different solvents and aggressive detergents for these purposes, which can lead to premature damage to the fan blades.

To clean and lubricate the inside, the tool must be disassembled. This infrequent procedure requires certain repair skills.

The technical condition of the nozzles used with the engraver should also be checked regularly. Worn nozzles should be immediately replaced with new ones, as they can cause increased vibration of the device, which will ultimately lead to its premature failure.

It is very important to pay constant attention to the technical condition of the engraver’s flexible drive shaft. The shaft protective cover, which is made of polymeric materials, should not have serious mechanical damage that could lead to premature shaft failure. After each use of the engraver, it is desirable to clean its drive flexible shaft from dust and other impurities, wipe and, if necessary, lubricate the tips with which it is connected to the electric motor and the working nozzle.

Liquid oil is used to lubricate the inner cable

In the process, it is necessary to ensure that the flexible shaft does not bend too much. Both during storage and during operation, it is necessary to protect the flexible shaft from mechanical damage.