Hard Anodized Coating Compensated Robot Base Plate and Datum Plate with 0.01mm Flatness

Send your drawing and receive a price within 24 hours. Prototype and batch orders are scheduled separately, with no tooling charge and no setup fee.

A robot base plate is the part every other part is measured against. The joint, the rail, the fixture and the workpiece all inherit whatever the base plate gives them. A plate that is 0.05 mm out of flat does not create one error — it creates an error in every assembly built on it. That is why this family is machined to 0.01 mm rather than to the general tolerance on the drawing.

Dongguan Changxinda Precision Technology Co., Ltd. has milled base plates and datum plates to drawing since 2008. The plant runs 4-axis and 5-axis machining centers, turn-mill combined lathes and precision CNC lathes, employs more than 90 people, holds ISO 9001:2015, and exports 50 to 60 percent of output to robot, automation and medical buyers.

Hard anodizing is not a paint. The coating grows out of the aluminum surface — roughly half into the part and half outward — at 20 to 50 microns per side depending on the specification. On a plate machined to 0.01 mm flatness, this matters in three places:

• Bolt holes close up: a 10 mm hole can finish 20 to 40 microns smaller, and an H7 fit for a dowel is gone.
• Pocket floors rise: a shallow pocket machined to 5.00 mm depth measures 4.96 mm after coating, which changes the stack height of whatever sits in it.
• Flatness drifts: coating thickness varies with current density, so edges and hole surroundings build faster than open faces, and a flat plate can leave the line slightly domed.

The fix is not to machine tighter after coating. It is to machine to a compensated drawing: holes opened by the expected coating growth, pockets cut deeper by the same amount, and critical fits masked instead of compensated. For a plate that must hold 0.01 mm, the compensation is calculated from the coating spec before the first cut — not discovered after the first reject.

• It is measured against, not measured on: every downstream tolerance is referenced to this surface, so plate flatness is multiplied through the assembly.
• It is thin relative to its size: a 12 mm plate at 400 mm square deflects under its own clamping force, so where it is supported decides what flatness is achievable.
• It carries the hole pattern: the position of the joint bores matters more than the plate outline, and the pattern has to be generated from the datum face, not from the saw cut edge.
• It travels: plates are shipped flat, stacked, and installed face down, so packing and handling can undo a good machining job.

• Datum face flatness 0.01 mm over the plate, measured on a granite plate with a dial indicator grid
• Opposite face parallelism to datum 0.02 mm
• Joint bore position 0.01 mm from the datum face and from the datum edge; bore diameter and roundness 0.01 mm
• Pocket depth 0.02 mm after coating, or 0.01 mm when the pocket is masked
• Plate thickness 0.02 mm, checked at nine points
• Hole position for the full pattern 0.02 mm, with dowel pairs reamed 0.01 mm
• Hard anodize 25 to 50 microns per side to the customer specification, with coating thickness reported per batch
• Metrology at 20 degrees Celsius, CMM resolution 0.001 mm, flatness map shipped with the plate

• Plate size from 100 x 100 mm to 1200 x 800 mm, thickness 6 mm to 60 mm
• Materials: 6061-T6 and 7075-T6 aluminum, 5083 for larger welded structures, 304 and 316L stainless where coating is not wanted
• Finishes: black or clear hard anodize, standard anodize, chromate-free conversion coating, nickel plating, with selective masking
• Features: T-slots, dovetail rails, dowel patterns, counterbores, cable channels, sensor pockets, lifting holes
• Laser engraved datum marks, axis labels and serial numbers, or no marking for confidential programs
• Matched pairs: two plates machined and measured as a set when the customer stacks them
• Drawing input in STEP, IGES, X_T, DWG, DXF or PDF, with the coating specification stated on the drawing so compensation can be calculated
• Prototype quantity from one piece, design feedback within 24 hours

A base plate reveals the layout of a robot cell or a machine. On request, this family runs on confidential terms: mutual NDA before drawings move, restricted file access with named staff, no photographs of the plate for marketing, sub-suppliers bound by the same terms, neutral marking and neutral packing, and programs and fixtures reserved to that customer. Mention it at enquiry stage and the quotation is issued under those terms.

• Prototype plate: 6 to 10 working days including stress relief and first article inspection
• Batch of 10 to 100 plates: 12 to 20 working days including hard anodizing
• Recurring releases: reserved machine capacity with the same fixture and the same compensated program, so hole sizes repeat batch to batch
• A named project engineer per account, weekly status update with photographs unless the program is confidential
• Written notice at least 5 working days before the ship date if any step is at risk, including the anodizing step
• Packing flat on a rigid pallet with faces interleaved, since a plate stacked on edge arrives bowed

Machined to drawing in the same plant, with the same tolerance and inspection standard.