How to calculate the quotation for non-standard CNC parts of robots? What is the proportion of material cost, hourly cost, programming cost respectively

When many R&D personnel submit part drawings for inquiry, they are accustomed to using part size material weight as the main basis for judging CNC precision machining budget. After receiving feedback various sources, it was discovered that some small-sized robot joints thin-walled cavity parts, even though the raw material cost is high, have a final quotation far exceeding psychological expectations. At its root, the processing cost of non-standard precision parts is solely determined by raw materials. Knife path programming, specialized tooling fixtures, multiple process flows, three-dimensional inspection, outsourced surface treatment, each of which will generate corresponding cost consumption. This article is based on the actual situation of outsourcing robot components in the industry, systematically breaks down the complete cost structure behind CNC precision machining quotations.

Robot non-standard CNC parts quotation disassembly: how various costs affect the final price

The following table is for engineering reference only is intended as a delivery commitment. The actual proportion may vary depending on the structure of the parts the quantity of 

The material cost is intuitive, but it may necessarily be the highest proportion of the cost. The proportion of material costs for ordinary simple board parts will be relatively prominent; However, complex thin-walled, multi-faceted hole system five axis parts such as humanoid robot joint shells dexterous hand components will incur high costs in terms of machine time programming tooling debugging. Even if the volume of the parts is small, if the structure is complex, the processing time will be greatly increased.

1. Material cost: equal to the weight of finished parts multiplied by the unit price of materials

The material cost cannot be calculated solely based on the weight of finished parts, but also includes the material loss caused by rough cutting cutting. 7075 T651 aluminum alloy, TC4 titanium alloy, PEEK engineering plastic, there is a significant difference in the purchase price of different grades of blanks; The larger the blank size selected, the more cutting waste there will be, the material cost will increase accordingly.

In the outsourcing of robot components, reasonable selection of raw material specifications evaluation of alternative materials without affecting the overall performance are effective means of controlling material costs. Huiwen Zhizao has passed the dual quality management system certification of ISO9001 IATF16949. It is a national high-tech enterprise a specialized innovative enterprise. When docking robot parts projects with Lenovo, Xinsong, Xiaomi Ecological Chain, Beijing Institute of Technology other units, it will provide reasonable suggestions for blank selection material substitution based on part working conditions, while synchronously conducting DFM manufacturability analysis to avoid processing risks in advance.

2. Programming Fixtures: Non standard Parts Cannot be Neglected as One time Investment

The programming workload for simple flat panel components is relatively small; However, the complex joint shell of robots has features such as deep cavities, multi angle oblique holes, thin walls, requiring CAM tool path simulation, specialized fixture design, first piece trial cutting verification, DFM review of some drawings to identify design risks such as sharp corners, thin walls, missing benchmarks.

Programming tooling are one-time investments. In the stage of single piece sampling, the cost of this part is fully allocated to a few products, the unit price per piece is relatively high; Entering small batch orders, costs can be allocated by quantity, individual prices will experience a significant decrease. A common misconception in the industry is to directly quote for a single sample as a budget basis for subsequent small batch purchases, resulting in budget errors.

3. Equipment bench time cost: just part cutting time

The machine time cost does equal the actual cutting time of the parts, but also includes all the time occupied by the machine tool, such as aligning positioning, multiple flipping, tool changing, first piece trial cutting, inter process inspection.

The hourly unit price of five axis equipment is higher than that of three-axis equipment, but for multi angle inclined holes complex curved parts, five axis equipment can achieve one-time clamping, avoid clamping errors caused by multiple flipping, reduce auxiliary working hours, the overall cost may be higher. On the contrary, if it is only a simple flat plate, three-axis equipment is sufficient to meet the processing needs, blindly choosing five axis equipment will bring unnecessary cost increases. The core of factory selection lies in equipment adaptation, rather than blindly pursuing five axis machine tools.

4. Testing surface treatment are free additional processes

Ordinary sizes rely on conventional measuring tools for inspection, resulting in lower testing costs; If the drawing requires three coordinate inspection, coaxiality of key hole groups, positional accuracy reports, retesting after surface treatment is completed, the inspection time will increase accordingly. Humanoid robot components have strict requirements for motion accuracy assembly reliability, critical dimension testing is a necessary step to ensure delivery quality.

Anodizing, hard anodizing, nickel plating are mostly outsourced processes, masking treatment retesting after treatment will change the quotation. This type of situation often occurs in the industry: in the early stage of inquiry, the requirements for surface treatment masking are specified, in the later stage, temporary additional requirements are added, the quotation delivery time will be re evaluated.

High frequency misconceptions

1. Misconception: For the same 3D drawing, quotes different companies should have direct comparability

Lack of written testing, post-processing, order stage constraints, each company follows their own default understanding to make process plans, the quotation is comparable.

2. Misconception: The unit price of prototype sampling can be directly used for small batch project budgeting

Programming tooling are one-time investments, small batches will result in cost amortization. Directly applying the unit price of the prototype will cause budget judgment errors.  

3. Misconception: Surface treatment testing are free accessories that come with processing

Covering three coordinate re inspection are independent processes, if the requirements are specified, the supplier will estimate based on the lowest default plan.

Frequently Asked Questions

Q: What is the main reason for the large difference in CNC quotation between two drawings with similar appearance?

A: Differences come multiple dimensions: raw materials, process route planning, tooling investment, testing requirements, surface treatment constraints, order quantity, cannot be solely based on appearance.

Q: How to determine if the process plan behind a quotation is suitable for your project?

A: Prioritize whether to provide itemized details verify whether the requirements corresponding to each item match your drawing's technical requirements one by one.

Q: Is 5-axis machining necessarily more expensive?

A: necessarily. Complex multi angle structure, five axis one-time clamping reduces flipping time, overall cost is controllable; Simple three-axis components offer higher cost-effectiveness.

Q: What is the inquiry process for non-standard parts of Huiwen Intelligent Manufacturing Robot?

A: After receiving the drawings, align all constraints of materials, order stage, testing, surface treatment, complete the preliminary DFM evaluation, output itemized disassembly quotations, cover prototype sampling to medium to large quantities. Huiwen Zhizao has ISO9001 IATF16949 quality management systems, a 20000 square meter factory, 370+precision production equipment, can undertake precision parts processing for humanoid robots scientific research equipment.

Conclusion

The quotation for non-standard CNC parts of robots is only the digital result of the entire process plan. Only comparing the total price, ignoring the constraints of the process, testing, post-processing behind the quotation, can easily lead to low prices but reduced solutions, ultimately resulting in component failure project delays. Aligning the entire set of technical conditions before inquiring is the prerequisite for comparing prices. In CNC precision machining outsourcing projects, Huiwen Zhizao will prioritize aligning all demand constraints before outputting itemized quotations to help the R&D team avoid budget delivery risks.