AMR Chassis Supplier RFQ Checklist for OEM Buyers

An AMR chassis RFQ should let a supplier quote a repeatable manufacturing process, not guess what the robot needs. A 3D model alone rarely defines how the frame is supported during inspection, which interfaces control navigation and wheel geometry, what the finish must protect or how a battery is serviced.

A complete package produces faster, more comparable quotes and exposes technical risk before purchase orders, fixtures and production inventory make changes expensive.

1. State the operating envelope and project stage

Open with one page of context. The fabricator does not need proprietary navigation code, but it does need the mechanical facts that affect the chassis:

• Indoor, outdoor-transition, cold-store, washdown or contaminated environment.
• Maximum payload and center-of-gravity envelope.
• Vehicle mass assumptions and major concentrated loads.
• Drive, caster or suspension architecture.
• Ground clearance and overall envelope constraints.
• Battery type, retention and intended service method.
• Payload or top-module variants.
• Prototype quantity, pilot timing, annual demand and order cadence.

Also state whether the design is a packaging prototype, a production-intent release or an established platform being transferred. A modular prototype fixture may be appropriate during rapid iteration; repeat production may justify dedicated tooling. The supplier cannot price that decision correctly without knowing design maturity.

2. Define the exact supply boundary

“AMR chassis” can mean anything from a bare weldment to a finished rolling platform. List what is included and excluded.

Scope item	RFQ decision to state
Sheet, plate, tube and extrusion	Supplier-purchased or customer-supplied; approved grades and conditions
Joining	Welding, mechanical fastening, adhesive or mixed process
Machining	Local pads, bores, threads and whether machining occurs after welding
Finish	Pretreatment, coating or anodizing, color, texture and masking
Hardware	Inserts, studs, fasteners, bearings, isolators and approved sources
Assembly	Mechanical modules, covers, battery tray, wheels or fit-check only
Inspection	First-article report, attribute gauges, capability evidence and sampling
Delivery	Loose parts, subassembly, complete kit, packaging and identity

If drive modules, batteries or sensors are customer-supplied for assembly, identify who inspects incoming items and who owns damage or incompatibility discovered at fit-up.

3. Release drawings around functional datums

The most important dimensions should connect directly to robot function. Establish a datum system for the supported chassis and use it consistently for:

• Drive and caster mounting planes.
• Vehicle centerline and axle or wheel references.
• Payload deck and top-module pattern.
• Safety scanner, camera and docking mounts.
• Battery rails, stops and connector bracket.
• Outer bumper and ground-clearance envelope.

Do not locate a calibrated sensor from a cosmetic cover unless that cover has a deliberate repeatable interface. Do not apply machining tolerances to the whole welded structure simply because a few mounting pads need precision.

For each CTQ, state the tolerance, inspection condition and acceptance method. A large frame may be measured on an articulated arm; repeated local patterns may be better protected with a hard gauge. The method should predict assembly.

4. Provide real load and support conditions

A generic payload number is not enough. The frame responds to where the load acts and how the wheels support it.

Include, as applicable:

• Payload center-of-gravity range.
• Drive and caster reaction locations.
• Acceleration, braking and controlled emergency-stop cases.
• Threshold, floor-joint and curb-transition assumptions.
• One-wheel lift or three-point support condition.
• Lift, conveyor, tow or manipulator reaction forces.
• Shipping restraints, hoist points and forklift handling.
• Service states with a battery or module partly withdrawn.

Separate strength from functional deflection. The chassis may remain intact while a drive pad, sensor tower or docking interface moves outside its alignment budget. State where stiffness matters and under what load it is evaluated. The OEM retains responsibility for the load definition and final vehicle validation; the fabricator needs enough released information to build the analyzed structure.

5. Include module envelopes, not just mounting holes

Hole patterns do not reveal tool access, cable bend radius, connector movement or the path needed to remove a drive or battery.

Provide simplified keep-out models for:

• Drive, caster and suspension modules.
• Battery, charger contact and retention hardware.
• Controller, power distribution and thermal hardware.
• Safety scanners, LiDAR, cameras and bumpers.
• Top modules, lifts, conveyors or collaborative-arm bases.
• Covers, latches, hinges and service tools.

Define whether representative components, gauges or dummies will be available to the supplier. A physical fit check can catch stack-up and access problems that individual dimension reports miss.

6. Control material, welding and finish

Specify material by recognized grade and condition, not by a vague family name. If alternatives are acceptable, require written approval before substitution. Bend performance, weldability, strength assumption and finish compatibility can all change with grade or temper.

For welded frames, identify joint requirements based on load and access. Avoid “weld all around” as a default note. Unnecessary weld length adds heat, cost and distortion. A supplier review should cover tabs and slots, fixture locators, tack sequence, balanced welding, post-weld machining allowance and free-state inspection.

Finish notes should cover the full system:

• Surface preparation or pretreatment.
• Coating or anodizing process.
• Color and texture where appearance matters.
• Masked threads, machined pads and ground paths.
• Edge and internal-section protection.
• Acceptance criteria and repair method.

Allow for coating thickness at battery slides, locating pilots, inserted hardware and cover gaps. Decide whether threads are protected, chased or verified after finish.

7. Make the first article production-representative

State which operations must match production. A first article made with temporary machining in place of bending does not validate the intended bend and weld process.

A strong first-article package can include:

1. Material and purchased-component identity where specified.
2. Ballooned drawing linked to measured results.
3. Weld and finish visual evidence against released criteria.
4. Wheel, sensor, payload and battery interface checks.
5. Free-state or defined-support measurement.
6. Representative cover and module fit check.
7. Record of approved deviations and drawing changes.

Do not request measurements for every dimension simply to create a thick report. Prioritize the features that predict function, assembly and interchangeability. Then define sensible production sampling for those feature groups.

8. Separate prototype, tooling and recurring cost

Ask suppliers to break out:

Cost line	Why it should be visible
DFM and programming	Distinguishes launch work from recurring conversion cost
Prototype or soft tooling	Shows what will be reused and what is temporary
Dedicated welding/checking fixtures	Lets buyers compare repeatability strategy
First-article inspection	Makes evidence scope explicit
Unit fabrication and finish	Supports volume and batch comparison
Purchased hardware	Reveals assumptions about approved sources
Kitting and packaging	Prevents downstream labor from disappearing from the quote

Request price breaks at realistic batch quantities, not only annual volume. A program using monthly releases has different setup economics from one annual order. Also identify what happens when a revision changes a fixture, gauge or finished inventory.

9. Review production readiness and change control

Before approving a supplier, ask how the company will control:

• Drawing, CNC program and work-instruction revisions.
• Fixture and gauge identity.
• First-off verification after a setup.
• Inserted hardware and purchased-component versions.
• Nonconformance and concession records.
• Traceability expected by the OEM.
• Mixed-platform kitting and packout.

Walk one hypothetical sensor-bracket revision through the system. Which old stock is blocked? How is the fixture checked? When does a new first article become necessary? Concrete answers are more useful than a generic quality presentation.

10. Watch for quotation red flags

A low quote deserves clarification when it:

• Omits fixture, finish, hardware or inspection assumptions.
• Prices from the 3D model while ignoring controlled drawing notes.
• Promises tight weldment tolerances without describing free-state measurement.
• Proposes a material substitution without structural or process review.
• Treats coating masks and ground paths as an afterthought.
• Uses a machined prototype to represent a formed production design.
• Includes “complete assembly” without a component responsibility list.
• Cannot state how revisions affect programs, fixtures and inventory.

Questions are not a sign that a supplier is difficult. Relevant questions show that the company is trying to quote the actual work.

Complete AMR chassis RFQ checklist

• Program stage and target launch date.
• Annual volume, release quantity and platform variants.
• Controlled 3D and 2D files with matching revision.
• Functional datum scheme and CTQ list.
• Payload, center of gravity, dynamics and support conditions.
• Drive, caster, sensor, battery and top-module envelopes.
• Material, bend, weld, machining and finish specifications.
• Grounding, masking, drainage and corrosion details.
• Approved hardware and customer-supplied component list.
• Prototype and production-intent first-article plan.
• Inspection methods, reports and production sampling.
• Mechanical assembly, kitting, identity and packaging scope.
• Required credentials and documentation stated explicitly.

Connect the chassis RFQ to system validation

The public summary for ISO 3691-4

covers safety requirements and verification for driverless industrial trucks and their systems, including AGVs and AMRs. Use the applicable system requirements to derive mechanical CTQs, but do not ask a chassis fabricator to certify an empty frame as a complete safe vehicle.

NIST’s mobile robotics test-method research is useful context for performance validation. The OEM should connect navigation, mobility and task tests to mechanical variables such as wheel alignment, ground clearance, sensor stability and loaded chassis behavior.

DRAmetal provides build-to-print robot and AMR chassis fabrication and broader robotics frame fabrication. Use our robotics frame supplier checklist as a qualification companion, compare aluminum and steel AGV/AMR chassis options, or send the completed RFQ package for DFM review and quotation.