Wheel dressing is one of the most under-utilised processes in grinding. The simplest and most basic dressing method is via the use of a dressing stick – made from either silicon carbide or more commonly aluminium oxide. As cutting tool materials become more advanced, it is necessary to optimise wheel performance by maintaining open and exposed wheel grit.
Contrary to the belief that dressing decreases wheel life, dressing actually improves the surface of the wheel during grinding and prolongs the wheel life. Dressing reduces grinding forces between the wheel and the tool and as a result also reduces cycle times. In turn, tool production is improved, and the flow on effect is an increase in profits.
Automatic whitesticking of grinding wheel
ANCA has developed an automated solution that allows in-between-cycle stick dressing that can be used for a wide range of grinding wheels, particularly for resin bonded CBN and diamond wheels. By automating the stick dressing process down time during production is reduced, allowing unmanned production runs as wheel condition is maintained during the batch. Operator safety is also increased as manual interaction is eliminated. Regular stick dressing of grinding wheels reduces tool burn and material damage, as well as ensuring open cutting wheels that reduce grinding forces and minimise spindle load. The noticeable results are a reduction in cycle times gained from improved feedrates and a significant increase in the life expectancy of your wheels.
ANCA’s industry renowned software, known for its flexibility and user-friendliness, fully supports the white stick dressing process, ensuring efficient use with the least amount of material removed. You can access white sticking via the “Dress Wheel” operation in ANCA’s iGrind software. This operation allows full control over:
• Selection of individual wheels from all available wheel packs on the machine
• Frequency of stick dressing
• Specification of the C-axis position during dressing
• Depth of sticking via plunge/wipe
• Compensation for wheel wear
• Selection of wheel surface (front, back or periphery)
• Selection of wheel position (3 o’clock or 9 o’clock)
Whitestick in Toolroom software page
ANCA’s automatic stick dressing assembly is pneumatically actuated so that the stick holder can drop to a horizontal position. The retract position for the stick assembly (on the Z-axis saddle behind the headstock) avoids interference issues with any of the machines optional extras, such as the loader, steady support, etc. There are two versions available for automatic stick dressing on the TX7 machine, the commonly used two-holder assembly that accommodates two separate dresser sticks, or the four-holder version.
Crusher Roll Grinding Wheel Dressing
Whilst white sticking can keep your wheel sharp and productive, it doesn’t replace the need in some production applications for the more aggressive dressing provided by roll crush dressers, which are used to accurately true the wheel to the correct shape and size. ANCA’s TX7+ accommodates this need with an optional motorised secondary-dresser unit providing the capability to perform any wheel dressing tasks you require, allowing automated dressing for unmanned production runs. The dresser unit utilises quick-changeover HSK arbors which allow you to perform quick and rigid mounting of dresser rolls to the machine in less than 30 seconds. Both the arbors and dresser unit feature a notched reference mark to ensure arbors are always mounted in the same orientation, ensuring minimal run-out. The HSK arbors are available in a variety of shaft sizes to suit a range of dresser rolls with common industry bore sizes.
HSK dresser unit
Adaptive Grinding
Another innovative option is ANCA’s ‘adaptive grinding’, which maintains constant spindle loads by automatically adjusting the feedrate to maximise efficiency and reduce cycle times. It also reduces wheel wear and improves surface finish. The spindle load limit is pre-defined and can be easily changed by the operator.
Coupled together with ANCA’s white stick dressing and crusher roll wheel dressing, ANCA has created a formative arsenal of wheel regeneration options to tackle any wheel loading issue and improve your cycle times in the process.
For more detailed information regarding this article, please contact your local ANCA representative.