How to get the best result with your portable line boring machine

Do you know how to get the best result with your portable line boring machine? What are the best practices to consider? Here’s a quick guide.

5 Best practices

Portable line boring machines are known to be multifunctional machines, thanks to the optional accessories and kits users can perform various types of machining. The versatility of the portable line boring machines of the Supercombinata series makes it possible to perform various steps of machining with extreme ease of use. Looking back on many years of experience, as well as the different requirements of our customers all over the world, made it possible to create a standardized procedure summarized in 5 steps in order to work progressively and optimally with your machine, to achieve timely and successful repair.


1 - Centering operation

The first task is the centering of the boring bar. After placing the centering kit supports on both sides of the hole to be machined, the position is fixed by small spot welding in order to fix the position of the boring bar in two points.

The boring bar is then inserted into the bushings provided for this purpose and a tool holder is inserted and fastened into a seat of the boring bar. By manually rotating the boring bar the upper tip of the insert has almost to touch the surface to be machined.

To perform the centring operation, it is necessary to adjust the centering screws on one side and then on the other side. For the final check, the telescopic dial gauge has to be used.

2 - The adjustment of the main supports

A good fixation of the supports is necessary, as they must withstand the weight of the machine and the torsional load caused by the flaking of the material with the cutting tool.

During the fixation of the supports, it is necessary to pay attention; the connection should be made by continuous fillet weld and the welding should consider the shear load and bending moment, determined by the weight of the machine and the installed equipment.

Finally, the portable line boring machine can be fixed and fastened to the main supports, through the threaded nut.

3 - Procedure for overlay welding

Safety goggles and safety equipment must be worn before welding operation is carried out. Then you can proceed as follows:

  • Cleaning of the surface on which the weld material is applied with suitable liquids. It is important to ensure that low-fat and low-oil products are used.
  • heating of the workpiece to approximately 100-150°C;
  • centering of the line boring machine;
  • mounting of the boring bar and boring to eliminate any ovalizations and residues of oily materials.

After performing the above steps, the machine can now be equipped for overlay welding:

  • adding the provided spacers for the extension of the terminal lance.
  • inserting the wire guide spring inside the extensions so that the length of the wire guide spring is about 1 mm less than the tip of the wire guide nozzle.
  • Then the wire nozzle is inserted into the last section of the diffusor extension.

It is recommended to use only wire nozzles and gas nozzles included in the standard equipment that you can buy from ELSA.

4 - Steps for line boring operations

After overlay welding operation, following operations can be carried out:

  • remove the torch;
  • lubricate the supports;
  • insert the boring bar from the rear of the machine, making the shaft key coincide with the machine seat;
  • Slide the boring bar through both previously welded main supports;

The problem of dimensional and geometrical tolerances and the achievable results in terms of surface roughness must be taken into account in the boring process.

To achieve high-quality results, you should pay attention to the following topics:

  • about 1 mm overlay welding;
  • a new cutting insert;
  • operate, compatibly with the torque values available on the boring bar, at the maximum rotation speed;
  • Feed rate of about 2/3 of full scale.
  • under sufficient lubrication conditions, obtained through specific products.

5 - Power and torque

All machines of the Supercombinata series are equipped with a mechanical 2/4-speed gearbox. The mechanical gear driven by the electric drive, combined with the stepless speed control, gives the line boring machines an extraordinary flexibility during the machining phases.

In this sense, the Supercombinata Series line boring machines can work in a very wide speed range with torque values on the boring bar, that allow the user to work easily both in the roughing and in the finishing operations.

It is recommended to observe the instructions on each unit observing the appropriate sticker and to enter the desired gear taking care to manually rotate the boring bar in order to facilitate the insertion.

Very close to your needs

Elsa offers training via video conference or directly at the manufacturer’s facility in Italy. It is also possible to ask for a training at its own headquarters, performed by a specialized technician.

For more information, please complete the form on the contact page or via live chat on our website. An employee will contact you as soon as possible.

For more information visit our website.

Bonifacio Monti, Mechanical engineer

Tag: Products