Clamping devices, lubrification and filtration for drills with internal cooling

General information

In the industry for metal work tools, shorter processing times are always in demand. At the same time, the requirements to the manufacturing precision and process reliability are growing. To fulfill these requirements, the "machine tool (all types of drilling machines) – spindle – tool – tool holder" system must be perfectly adjusted.

The following requirements have to be taken into account:

  • For the machine tool: High level of stiffness, vibration isolation of the foundations, lightweight design of the moving parts, high concentricity accuracy of the spindle, pull-in forces of the machine spindle, intelligent and quick machine controls
  • For the tool holder: High concentricity and balanced, friction-locked tightening of the tool
  • For the tool: High concentricity, excellent balance quality (geometry and shank design), long tool  life (tool material, geometry, coating)

Tool Holders

Hydraulic expansion tool holder

These ensure the high concentricity during drilling.

MikronTool-products-Additional-Tech-Specs-Tool-Holders-Hydraulic

Characteristics:

  • Concentricity: 0.003 mm (.00012”) (measuring point at 2.5 x D)
  • Max. speed: 50'000 rpm / balance rate (G 2.5 / 25000 1/min)
  • Precise concentric clamping
  • High torque transmission
  • Maintenance-free (closed system)
  • No wear in the clamping diameter
  • Longer (up to 4 times) tool life
  • Adjustable clamping force
  • Short tool change time (without additional devices such as, shrink fit device)

Application:

  • High-precision clamping of tools with cylindrical shaft
  • Universal tool holder for drilling and milling (roughing and finishing). Advantageous in the case of HSC processing (milling, for example on a small CNC milling machine) due to its shock-absorbing.

Shrink fit tool holder - shrink fit tool holder according to DIN 69871 

These guarantee highest concentricity with secure friction-fit connection and form an optimal connection between the tool and the holder.

MikronTool-products-Additional-Tech-Specs-Tool-Holders-Shrink-Fit

Characteristics:

  • Concentricity: ≤ 0.003 mm (.00012”)
  • Max. speed: 40'000 rpm
  • Absolutely secure friction-fit force transmission
  • Adequate for shaft diameter of 4 mm (.157”) (3 mm (.118”) are conditionally possible).
  • Transmittable torque 2 to 4 times higher compared to the hydraulic-tool holder and the high precision collet tool holder.
  • Average tool change time (shrink fit device is necessary)
  • Suitable for machining in narrow spaces and interfacing edges due to the small overall construction size and longer versions

Application:

  • Optimal for HSC machining, in particular also for smallest drill bits
  • For milling and drilling tools with cylindrical shaft

Collet tool holder systems (ER collet chucks) according to DIN 6499-A / optimized precision collets

These guarantee highest concentricity.

MikronTool-products-Additional-Tech-Specs-Tool-Holders-ER-Collect

Characteristics:

  • Concentricity: 0.003 mm (.00012”) possible
  • Max. speed: 40'000 rpm
  • Average tool change time (a torque wrench is necessary)

Application:

  • Clamping of tools with a cylindrical shaft in high precision collet according to DIN 6499
  • Universal tool holder for milling (roughing and finishing) and drilling.

Balance quality

The balance  quality of the collet tool holder is specially critical  in high speed machining processes.  The best possible balance  quality guarantees not only reduced vibrations of the tool  but increases tool life, improves surface quality and  above all, protects the spindle bearings.

Types of drilling machines

CrazyDrill Coolpilot Titanium can be used on all types of drilling machines, CNC machining centers, automatic lathes or transfer machines.

  • Minimum speed 10,000 rpm (drill size diameter 1 mm / .039“)
  • Minimum speed   3,000 rpm (drill size diameter 3 mm / .118“)
  • Minimum concentricity of spindle 5 µm (.00019“)

Coolant type / Filtration / Pressure

For best results, Mikron Tool recommends the use of 8% emulsion with EP-Additives (Extreme-Pressure-Additives) as coolant fluid. Alternatively, cutting oil can be used with good results as well.

Filtration: Good filter quality is very important when using through coolant twist drill types. Dirt particles or residual chips can clog the coolant holes and consequently reduce dramatically the flowrate. The following filter qualities must be adhered especially in small diameters: 

                    Twist drill type Ø < 2 mm (.079“) filter quality ≤ 0.010 mm (.0004“)
                    Twist drill type Ø < 3 mm (.118“) filter quality ≤ 0.020 mm (.0008“)
                    Twist drill type Ø < 6.35 mm (.236“) filter quality ≤ 0.050 mm (.0020“) 

Chart for coolant pressure
The minimum coolant pressure mentioned in the chart is required for the CrazyDrill Coolpilot Titanium, the pilot and short drill for titanium alloys, to achieve reliable drilling. Higher pressure is generally better for the cooling and flushing effect.

Pressure