How to ensure the flatness of a 3D welding platform?

How to ensure the flatness of a 3D welding platform?

The flatness of a 3D welding platform requires comprehensive control across five key aspects:material and structure,precision machining,installation and leveling,use and maintenance,and regular calibration.Only then can it consistently achieve the industry-leading precision standard of 0.05–0.1 mm/m.

I.Source Control:Material and Structural Design(Deformation-Proof Foundation)

Prefer High-Stability Materials

The mainstream choice is HT300 gray cast iron(tensile strength≥300MPa)or high-strength cast steel;these materials offer good thermal stability and high rigidity,resisting welding heat deformation.

Completely Eliminate Internal Stress

After casting,the platform must undergo 550℃high-temperature aging+at least 6 months of natural aging,achieving a residual stress removal rate≥85%,preventing deformation after long-term use or exposure to heat.

Rigid Structural Design

The bottom adopts a cross-ribbed design with a box-shaped main structure.The ribs are 12–15 mm thick and spaced approximately 200 mm apart.For large platforms(e.g.,2000×3000 mm),the platform deflection can be controlled to**≤0.03 mm**under a 5-ton load.

II.Precision Machining:Platform Precision"Grinded"Out

Multi-stage ultra-precision grinding

The platform undergoes three processes:rough grinding→fine grinding→ultra-precision grinding.Ultra-precision grinding uses an 800#grinding wheel with a feed rate≤0.005 mm/cycle,achieving a final surface roughness of Ra1.6μm and a flatness of 0.05 mm/m(Grade 0).

Unified Hole System and Datum

Positioning holes(φ16/φ28 mm)are machined using a CNC gantry milling machine with a center-to-center tolerance of**±0.05 mm**,eliminating cumulative errors.The entire platform is machined using the same datum,ensuring consistent plane and hole system precision.

Manual Scraping and Finishing:For platforms requiring high precision,a final manual scraping and finishing process is performed to ensure that the number of contact points within a 25mm x 25mm area meets the standard(Grade 0≥25 points).

III.Installation and Leveling:On-site leveling is crucial.

Foundation and Support:The platform must be installed on a solid,level foundation or a dedicated support frame;a layout of 3 main support points(fixed plane)+auxiliary support points is used to avoid suspension and uneven local stress.

High-Precision Measuring Tools:Coarse adjustment is done with a 0.02mm/m frame level,followed by fine measurement with an electronic level/optical alignment level;testing is conducted using a"米"(two diagonals+four sides)layout.

Leveling Process:

Coarse Adjustment:Adjust the main support bolts to center the level bubble.

Fine Adjustment:Use a feeler gauge or dial indicator to check the height difference at each point and fine-tune the auxiliary supports.

Tightening:After leveling,tighten all bolts to prevent loosening.

Multi-Platform Assembly:Align with dedicated positioning pins during assembly,level the entire surface,and then fix it to ensure continuous flatness of the splicedsurfaces.

IV.Use and Maintenance:Maintaining Lasting Accuracy

Reasonable Load Bearing:Avoid overloading;distribute load as evenly as possible;avoid localized concentrated pressure that could lead to permanent deformation.

Controlling Welding Heat Effects:Use low current,short arc,and segmented welding during welding,and utilize water/air cooling to reduce localized thermal deformation of the work surface.

Daily Maintenance:Keep the working surface clean and apply anti-rust oil regularly;avoid impacts and scratches;cover and protect when not in use.

Standardized Handling:Use dedicated lifting points for hoisting;pad and secure the surface during transportation to prevent vibration and compression deformation.

V.Regular Inspection and Calibration:Preserving Accuracy

Inspection Cycle:A comprehensive inspection is routinely performed every 6–12 months;for high-load environments,inspection is recommended every 3–6 months.

Inspection Methods:

Level Method:Measure at multiple points along the platform grid lines and diagonals.

Plaster Plate Comparison Method:Use a higher-precision standard plate,along with a feeler gauge/dial indicator for inspection.Laser flatness gauge:Suitable for large platforms,providing fast and high-precision measurement.

Calibration and Repair:When flatness exceeds tolerance,professional manufacturers will perform re-scraping/fine grinding repair;severe deformation requires re-aging treatment before further processing.

Common Flatness Standards Reference:

Grade 0:≤0.05mm/m(Precision welding,inspection benchmark)

Grade 1:≤0.1mm/m(General high-precision welding)

Grade 2:≤0.2mm/m(General welding fixtures)

GB/T 7714:Arslane M, Slamani M, Louhichi B. Advancements andoptimization in fixture layouts and machining processes: acomprehensive review in the context of Industry 4.0[J]. TheInternational Journal of Advanced Manufacturing Technology,2025, 137(11): 5387-5404.

MLA:Arslane, Mustapha, Mohamed Slamani, and Borhen Louhichi."Advancements and optimization in fixture layouts andmachining processes: a comprehensive review in the contextof Industry 4.0." The International Journal of AdvancedManufacturing Technology 137.11 (2025): 5387-5404.

APA:Arslane, M., Slamani, M., & Louhichi, B. (2025).Advancements and optimization in fixture layouts andmachining processes: a comprehensive review in the contextof Industry 4.0. The International Journal of AdvancedManufacturing Technology, 137(11), 5387-5404.