What is center looping?
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Center grinding – The optimal and essential preparation of a component to achieve the final high-precision grinding process after hardening.
Components can warp during heat treatment. The result is out-of-round and deformed center holes, which lead to inaccurate results in subsequent grinding operations. Center grinding is a necessary preparatory process, especially when components are further processed on multiple machines after hardening (cylindrical, gear, thread grinding, etc.).
Profit:
- High roundness and concentricity of the center hole of 0.001mm
- Restore the axis in deformed components
- Establish the coaxiality, e.g., between a finished bearing seat and the center bore
- Minimization of cylindrical grinding time through smaller grinding allowance
- Achieving higher efficiency, greater accuracy, and a lower scrap rate in further processing
- Increasing process reliability in series production
Advantages specifically with our
Precision chuck:
- Grind the center coaxially to a bore, even though clamping is done on the deformed and out-of-round outer diameter.
(With the chuck, the components can be aligned, for example, according to a bore) - Intentional shifting of the axis (if required by the component)
Application examples
Roundness
Achieving high roundness and concentricity in the center
Surface finish
Achieving the optimal surface finish for cylindrical grinding between centers (crosshatch finish)
Non-circular parts
Aligning out-of-round components with the chuck to minimize the grinding allowance
Moving the axis
Aligning the component according to the bore and grinding the center eccentric to the outer diameter
Positioning error
Correct position error of two centers
align
Restore the axis of two centers relative to the outer diameter
central angle
Restoration of the desired central angle
Grinding the center holes on the center grinding machine brings very great and unavoidable advantages
Centerless grinding corrects form and position errors. As a result, hardening depths and grinding allowances can be minimized..
Thus, the component has the perfect starting position for all further processing steps.
Where are centerless grinding machines used?
Spindle manufacturing
Mechanical engineering (grinding machines, machine tools, etc.)
automotive industry
Engine manufacturing
aviation industry
Gearbox manufacturing
Wind power
Gear manufacturing
Gripping and clamping technology
Plumber
Component manufacturing (ball screws, etc.)
Tool manufacturing (solid carbide tools, etc.)
Tool holders
many more
Why a ZAMAG centerless grinding machine?
All ZAMAG centerless grinding machines work with rotating workpiece. This brings many advantages with it. Components with pre-ground or already finished bearing seats can thus be easily clamped in the steady rest. Due to this clamping method, the centers are automatically ground coaxially to the bearing seat. However, this requires that the bearing seats have good roundness, as this is transferred to the ground center.
Even more advantages arise when clamping and grinding the rotating workpiece in our precision clamping chuck. Using the three adjustable quills in the clamping chuck, the parts can be aligned precisely. Thus, it is no problem to clamp even raw or out-of-round components. By aligning the outer diameter, the center is ground coaxially to the axis. This allows the grinding allowance to be kept to a minimum.
In addition, there is the possibility of clamping the component by its outer diameter, but aligning it relative to the bore. Thus, the component is intentionally clamped eccentrically. This procedure is used when the outer diameter is subsequently to be ground coaxially to a (e.g., honed) bore on the cylindrical grinding machine.
grinding principle
1 Rotational movement of the grinding wheel
2 Stroke movement of the grinding wheel
3 Rotating workpiece
Result
A cross-hatch finish with oil pockets that maintains the oil film during cylindrical grinding between centers.