Applications
Machine Bases, by the Machine They Carry
A press frame and a CMM table are both machine bases, and almost nothing about them is specified the same way. What each kind of machine asks of its base, the construction that usually follows and what to put in the RFQ. Typical practice for each class of work, not promises.
No fee for buyers. Reply within 24 business hours, including when we cannot place it.
Applications at a glance
The machine on top decides which property comes first. Construction choices and property data are in the construction comparison, and how each one is made is in manufacturing technologies.
| Machine | Usual construction | What decides it | Say in the RFQ |
|---|---|---|---|
| Machine tools | Grey iron casting, stress relieved welded steel, filled weldment | Stiffness under cutting load, damping, geometry of the guide rail faces | Rail mounting faces, their flatness and parallelism, and the finishing method |
| Grinders | Grey iron, mineral casting, filled weldment | Damping and thermal stability before stiffness | Thermal and vibration targets, insert positions, finishing of the way faces |
| CMMs and metrology | Granite table and bridge, mineral casting, stress relieved steel frame | Long term stability, thermal inertia, flatness of the reference surface | Granite grade and flatness grade, insert pattern, how flatness is measured |
| Laser and waterjet cutters | Welded steel bed and gantry frame | Large size, high axis acceleration, heat from the cutting zone | Rail faces over the full length, stress relief method, split points |
| Semiconductor and inspection | Welded steel or stainless frame, granite stage base | Vibration, flatness of the stage base, clean finishes | Natural frequency or vibration criterion, finish and cleaning, isolator interfaces |
| Presses | Heavy plate welded frame, C-frame or straight side | Deflection under rated load, fatigue at the welds | Rated load, allowed deflection, weld inspection on load paths |
Application
Machine tools
Machining centres, lathes, boring and milling machines carry their guideways and spindle directly on the base, bed and column, so the geometry of the finished machine is measured against them. Grey iron is the default for a repeat model in steady volume. A stress relieved steel weldment wins on the first units and on sizes too big for a convenient pattern. The machine itself is later checked to the ISO 230-1 geometric tests, which is why the rail faces on the base matter more than any other surface.
Put in the RFQ
- Rail size and type, and which faces carry them
- Flatness, parallelism and squareness between rail faces
- Ground, scraped or finish milled faces
- Stress relief or ageing method before machining
Guides: Cast Iron or Welded Steel: Choosing a Machine Base Construction · How Stiff Does a Machine Base Need to Be?
Application
Grinders
Surface, cylindrical and tool grinders remove microns at a time, so vibration and slow thermal drift show directly in the finish and the size of the part. Damping and thermal stability come before raw stiffness. That is why grinder beds are grey iron or mineral cast, or a steel weldment with a filled core when the volume does not justify a mould. A symmetrical layout, so the base grows evenly as it warms, matters as much as the material.
Put in the RFQ
- Vibration or surface finish target on the machine
- Thermal behaviour you rely on, in writing if mineral cast
- Insert positions and tolerances for cast in parts
- Way faces and how they are finished
Guides: Polymer Concrete or Cast Iron: A Straight Comparison · Epoxy Granite Machine Bases: When Mineral Cast Is Worth It · Grinding Machine Bases: Damping and Thermal Stability Rules · Filling a Weldment: Damping Without the Pattern
Application
CMMs and metrology frames
Coordinate measuring machines are built on a reference surface that has to stay flat and stable for years. Natural granite is the usual table and often the bridge, because it is thermally slow, does not rust and does not carry the internal stress of a weldment. Flatness of granite plates is graded to standards such as DIN 876 or ASME B89.3.7. The finished machine is verified to ISO 10360, so the base supplier's job is the stable reference, not the accuracy claim. Background on the machine type is on Wikipedia.
Put in the RFQ
- Granite type and the flatness grade of the reference face
- Threaded insert pattern and pull out loads
- Support points for the granite, usually three
- How flatness is measured and reported
Guides: Granite Machine Bases: Stone Grades and Flatness Classes · How Machine Base Flatness Is Actually Measured
Application
Laser and waterjet cutters
Flat bed cutting machines put a fast gantry over a long welded steel bed. The bed has to keep its rail faces straight over many metres, and the gantry has to be stiff for its mass because axis accelerations are high. The cutting zone puts heat and slag into the bed, so the slat support and fume extraction are usually separate from the precision structure. Beds longer than a convenient furnace or truck are made in sections with machined joint faces.
Put in the RFQ
- Bed length and the straightness of the rail faces
- Stress relief method, thermal or vibratory
- Split points and how the sections align
- Mass and stiffness targets for the gantry
Guides: Stress Relief and Flatness: Why a Machined Base Moves · When to Split a Machine Base Into Bolted Sections · Designing the Base of a Gantry Machining Centre
Application
Semiconductor and inspection equipment
Wafer inspection, metrology and handling tools mount stages and optics on a frame that sits on vibration isolators. The frame has to keep its first natural frequency well above the excitation from the floor and the stage, and the stage base has to stay flat once assembled. Floors in these fabs are classified against vibration criterion (VC) curves, and the tool maker sets the frame target from that. Finishes have to suit the cleanroom: powder coat or paint that does not shed particles, or stainless.
Put in the RFQ
- Natural frequency or vibration target for the frame
- Flatness of the stage or granite base
- Coating system and cleaning before packing
- Isolator and levelling interfaces
Guides: Chatter, Natural Frequency and What the Base Can Fix · Using FEA on a Machine Base Without Fooling Yourself
Application
Presses
Hydraulic and mechanical press frames carry the full press force through the structure on every stroke. The design limits are deflection under rated load, stated as mm per metre of bed width, and fatigue at the welds, because the load cycles millions of times. Frames are heavy plate weldments, C-frame for open access or straight side for higher tonnage and lower deflection, sometimes with pre-stressed tie rods. Full penetration welds on load paths are usually ultrasonically tested, and the frame is stress relieved before the bed, slide guides and cylinder seats are machined.
Put in the RFQ
- Rated force and allowed deflection of bed and slide
- Weld joints on the load path and their NDT
- Stress relief method
- Machined faces: bolster seat, slide guides, cylinder mounting
Guides: Fabricating Hydraulic Press Frames: Fatigue and Deflection · Designing a Weldment So It Can Actually Be Machined · Ribbing a Machine Base: Spacing, Section and Layout
Questions about applications
Not sure which construction your machine needs? Send the drawing to and we will say plainly where it fits, or that it does not.
The checks worth asking for on any of these bases are on quality and inspection.
Does the same construction suit every application?
No. A press frame needs strength and fatigue life, a grinder needs damping, a CMM needs a stable reference surface. The construction follows from what the machine on top needs first, then from volume and lead time.
Can one fabricator build bases for all of these machines?
Rarely. Foundries cast iron beds, fabricators build weldments and press frames, and granite and mineral casting are specialist trades. We put each drawing in front of fabricators or foundries that already build that construction at that size.
Who guarantees the accuracy of the finished machine?
The machine builder. The base supplier is responsible for the tolerances on its drawing, such as flatness and position of the mounting faces. Geometric tests of the machine, for example to ISO 230-1 or ISO 10360, happen after assembly.
Do you build the bases?
No. We are a sourcing service, not a foundry or a fabrication shop. We read your drawing and pass it to up to 3 fabricators in Vietnam that build that class of structure. They quote you directly. Reply within 24 business hours.