Clamping devices, lubrification and filter
for milling cutter CrazyMill Cool SF
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.
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.
Characteristics:
- Concentricity: ≤ 0.003 mm (.00012")
- Max. speed: 40'000 rpm
- Absolutely secure friction-fit force transmission
- Adequate for shaft diameter of 4 mm (.158") (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.
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.
Type of machines
CrazyMill Cool SF can be used on milling machines (for example micro milling machine), CNC machining centers (for example small CNC milling machine) and transfer machines (for example rotary transfer machine).
- Minimum speed 10'000 rpm (diameter of the milling tool > 3 mm (.118"))
- Minimum speed 20'000 rpm (diameter of the milling tool < 3 mm (.118"))
- Minimum concentricity of spindle 5 µm (.00019")
Coolant / filter, coolant pressure and quantity
For best results, Mikron Tool recommends the use of cutting oil as coolant fluid. Alternatively, emulsion of 8% or more with EP-Additives (Extreme-Pressure-Additives) can be used with good results as well.
- Filter: the large cooling channels allow the use of a standard filter. Filter quality ≤ 0.050 mm (.0020")
- Coolant pressure: for CrazyMill Cool CF, with IK (milling tool with through-shank cooling), at least 15 bar (218 psi) of coolant pressure is required to achieve optimized results.
Higher pressure is generally preferred for greater cooling and flushing effect.
Chart for coolant pressure and flow rate:
Cooling lubricant: cutting oil, viscosity category 15
Depending on the shaft diameter the number of coolant channels varies.
- Milling tool with 12 mm (.472“) shank: 5 cooling channels
- Milling tool with 10 mm (.394“) shank: 5 cooling channels
- Milling tool with 8 mm (.315“) shank: 4 cooling channels
- Milling tool with 6 mm (.236“) shank: 4 cooling channels
- Milling tool with 4 mm (.158“) shank: 3 cooling channels
Work piece clamping
Work piece clamping is extremely important when milling due to the appearance of radial and axial forces. Vibrations on the work piece affect not only surface quality and precision of the work piece but also tool life. Work piece clamping that is as vibration-free and stable as possible is therefore recommended.