In the fields of semiconductor inspection, optical processing and high-precision measurement equipment, granite machine bases serve as the core measurement datum for equipment thanks to high rigidity, low vibration and low thermal expansion characteristics. Many manufacturers strictly verify factory specifications including flatness and straightness of stone during procurement. The equipment delivers favorable precision at the initial commissioning stage. However, measurement repeatability declines and gradual datum drift emerges after a period of operation. A large number of on-site cases confirm that most of such precision abnormalities stem not from raw material defects of granite, but from improperly designed layout of support points during installation. Self-weight load continuously induces invisible micro-deformation of stone. Micro-scale deformation is invisible to the naked eye, yet sufficient to break the datum stability of submicron-level precision equipment, resulting in repeated debugging and production capacity losses.
Supported by finite element stress simulation analysis and abundant practical project experience, we go beyond superficial leveling operations. We sort out core ideas for support layout design from multiple dimensions including mechanical distribution logic, point layout criteria, matching of support structures and adaptation to later operating conditions. These insights help equipment R&D and engineering teams avoid load-induced deformation risks and permanently retain the original machining precision of granite bases.
When designing support layout, one common misunderstanding needs to be clarified first: more support points do not equal higher stability. To pursue greater bearing capacity, many field engineers add numerous rigid supports evenly under the base while ignoring minor unevenness of the ground foundation. When multiple rigid supports prop up the stone simultaneously, partial supports tend to make virtual contact and local supports bear overload pressure. Interlaced bending stress forms inside the stone and triggers continuous slow deformation. The classic three-point support arrangement can uniquely define a geometric plane and suits small and medium-sized integrated granite bases. Nevertheless, for heavy-duty bases with side lengths exceeding 1500 mm, a simple three-point layout easily leads to midspan sagging under self-weight and settlement deformation at the central area. For large-size components, the mainstream industrial solution adopts a hybrid framework of "main positioning supports + floating auxiliary supports". Three non-collinear main supports establish the datum plane, while other auxiliary supports reserve tiny floating clearance only for load sharing, eliminating internal stress caused by forced constraints.
The placement of support points directly determines the bending moment distribution of stone, and the distance between points and edges follows clear mechanical boundaries. If supports are placed closely against the four outer corners of the base, the middle section bends downward under self-weight. If supports are arranged excessively close to the center, four corners form suspended cantilever structures, and micro warping deformation persists at edges. The layout of support points for precision granite bases can refer to Bessel support points. Supports shall be arranged at a specific proportional distance from stone edges to counteract bending moment generated by self-weight and minimize the maximum deflection of the base. Standard rectangular plate support schemes cannot be directly applied to special-shaped granite bases equipped with T-slots, hollow weight-reduction structures and long cantilever guide rail mounting positions. Differentiated layout shall be formulated according to the structural outline and hollow areas of the base to avoid weak stone cross-sections and prevent continuous deformation triggered by stress concentration.
Treatment of support contact interfaces is often overlooked in layout schemes. Even with well-planned support positions, direct rigid contact between hard metal feet and the bottom surface of granite creates extremely high local contact pressure. Long-term loading not only easily causes indentation damage on the stone bottom, but also leads to local concave deformation within contact zones. For standardized installation, homogeneous flexible buffer pads shall be installed at support points to evenly disperse contact pressure. Meanwhile, the contact area of pads should be controlled to avoid full-surface supporting. For spliced split granite bases, each segmented support system must remain mutually independent. Support structures shall never be used to forcibly correct height differences at splicing gaps. Forcibly pulling stone for alignment via supports locks massive residual stress within joint areas. Stress releases gradually as ambient temperature varies and triggers geometric distortion of joint planes. 
Ground foundation conditions are a prerequisite for effective support layout. Support schemes cannot compensate deformation arising from foundation defects. If the installation ground suffers insufficient bearing capacity or uneven settlement, the horizontal state of the base will slowly change regardless of optimized support arrangement. Before formally arranging supports, confirm that floor strength meets requirements and avoid passageways and zones with weak load-bearing performance. Complete support placement and preliminary leveling, yet refrain from full-equipment precision inspection immediately. Granite bases undergo slow stress redistribution under self-weight. A sufficient standing period must be reserved until deformation stabilizes before precise re-measurement and secondary fine adjustment. For workshops with significant diurnal temperature variation, the coupling effect of thermal deformation and support constraints also needs consideration. Prevent rigid supports from restricting natural thermal expansion and contraction of stone, which would induce additional bending stress.
Support layout constitutes a mechanical balance system, where the quantity, placement, contact form of supports and foundation conditions interact and restrict one another. Random arrangement of supports merely based on operational experience can hardly restrain granite micro-deformation fundamentally. Factory flatness of the base is only an initial condition, while scientific and reasonable support layout acts as an essential guarantee for long-term datum stability.
UNPARALLELED GROUP possesses complete processing capacity for large-span and special-shaped granite components. We can conduct stress simulation according to clients' 3D drawings of bases and provide reference schemes for support point arrangement. We keep offering customized granite structure solutions as well as installation process guidance for metrology laboratories, laser equipment manufacturers and semiconductor automation enterprises worldwide. Feel free to communicate in depth with our technical team if you encounter technical questions regarding granite base scheme design and on-site assembly.