Internal & external surface tool set-up
The carbide burnishing tools are available with metric and imperial shank sizes and mount in the machine using the flat on the shank. Note that the pivot point of the tool should be at 90º to the burnishing pressure point.
The Elliott carbide burnishing tool has two series of springs for bi-directional spring loading. One series of springs, located in the shank, allows the entire head assembly to deflect when the carbide roll is pushed against the surface of the part. A second spring is located behind the carbide roll. This spring allows for deflection of the carbide roll when the tool is fed directly into a flat face surface or shoulder.
The spring deflection and feed rate must be determined to ensure the correct finish is generated by the tool.
The deflection should be determined first. Bring the carbide roll so it just touches against the work piece then feed the tool in until the spring has been deflected 0.5mm – 0.6mm [0.020” – 0.024”]. Upon deflection, feed the tool across the surface of the part at a feed rate between 0.1mm – 0.2mm/rev (0.004” – 0.008”/rev).
Check the finish achieved. If it is unacceptable, you can either increase or decrease the spring pressure using the set screw in the side of the shank, or increase or decrease the feed rate. Be sure not to exceed the maximum deflection of 2.5mm (0.100”) as this will damage the tool.
If you feed the tool on or off the end of the part, or burnish intermittent part surfaces, keep the amount of deflection to a minimum and tighten the set screw in the shank to increase the burnishing pressure.
Flat Face tool set-up
Feed the tool forward until the carbide roll contacts the face of the work piece and then deflect the tool a further 0.3mm - 0.4mm [0.012” - 0.016”]. Upon deflection, feed the tool across the surface with the roll leading at the point of contact, at a feed rate between 0.1mm – 0.2mm/rev (0.004” – 0.008”/rev). Check the finish achieved. If it is unacceptable you can either increase or decrease the spring deflection, or increase or decrease the feed rate. Be sure not to exceed the maximum deflection of 1.5mm (0.0640”) as this will damage the tool.
The carbide tool can burnish most materials up to 40 HRc, from a 2.5µm (100 CLA) pre-finish, to 0.05-0.2µm (2-8 CLA). Harder materials can also be burnished, but with lesser amounts of improvement.
Part Preparation – 2.5µm - 3.0µm (100 - 120 CLA) constant and tear free finish
Speed: Up to 350m/min (1200SFM) Feed Rate: 0.1mm - 0.20mm (0.004”/0.008”)
Coolant Required – water soluble or oil. The surface of the carbide roll can be damaged if the tool is used without flood coolant.