Why is there a difference of several times in the quotation of robot CNC processing manufacturers for the same drawing?

Why is there a difference of several times in the quotation of robot CNC processing manufacturers for the same drawing? Many people encounter a phenomenon when purchasing parts for the first time: sending the same drawing to several factories for inquiry, the lowest quotation may only be 500 yuan, but the highest can be reported as 1500 yuan, with a difference of even more than three times. Did someone intentionally quote a high price?  necessarily. For the manufacturing industry, the same dimensions on the drawings do  necessarily mean the same processing costs. Behind the quotation lies a complete set of differences in equipment grade, process plan, material standards,  testing  delivery. Low price solutions often compress costs in hidden places,  only expose problems such as size deviation, surface defects,  insufficient stability during the prototype assembly stage, which delays the robot project milestones. For the purchaser, it is far more important to first understand the quotation composition of the robot processing manufacturer before deciding which one to cooperate with, rather than simply comparing prices.

1、 Different equipment configurations are the main source of price differences

On the same drawing, some manufacturers use three-axis ordinary CNC, while others use five axis linkage; The age, brand,  accuracy level of the machine tool directly determine the labor cost. Complex shaped parts such as robot shells, harmonic reducer shells,  force feedback handles require multiple clamping of the three axes, resulting in accumulated errors; Five axis one-time clamping molding has high precision, but the depreciation  labor cost of the machine tool are much higher than those of three-axis equipment, which is also the most direct reason for the price difference between different CNC machining manufacturers.

2、 The price difference between raw materials  incoming standards can easily widen

On the drawing, only 7075 aluminum alloy is written,  there are huge differences in the delivery channels of different manufacturers: recycled remelted materials, domestic ordinary aluminum rods,  aviation grade original aluminum materials, with significant differences in unit prices. There is also material pretreatment: whether to perform stress relief aging directly affects the subsequent deformation of the parts. Low price suppliers often choose non time sensitive materials,  after processing, the parts slowly deform, causing the robot to jam after assembly; Legitimate robot processing manufacturers will use stress relieving raw materials, which increases the cost of raw materials, but the stability of the finished product is better. This is also an important reason for the differences in quotes between different CNC processing manufacturers.

3、 Process scheme selection, many costs are written outside the drawings

Drawing dimensions are indicated, but the complete process route is  written, which is another major source of price differences for robot processing manufacturers:

Rough machining allowance: Low price solutions have small rough machining allowance, which is prone to deformation;

The high demand scheme involves rough machining → time efficiency → precision machining, with an additional process  increased working hours;

Surface treatment: Same anodizing, ordinary anodizing, hard anodizing, sandblasting+high gloss chamfering, with completely different costs;

The drawings are  clearly marked,  low-priced manufacturers default to the minimum standard;

Deburring  sharp edge treatment: Robot precision parts with burrs can affect assembly,  manual fine deburring requires high labor hours. Low price orders often omit the fine deburring process.

4、 There is a significant difference in implicit costs between testing standards  quality control investment

Many purchases only focus on drawing dimensions  ignore the inspection process.

Low price factory: only conducts caliper sampling inspection, does  perform coordinate testing on complex surfaces,  qualification relies on worker experience;

Precision machining factory: Zeiss conducts a complete set of inspections including CMM, height gauge,  micrometer, including first piece inspection, process inspection,  final inspection. A testing report is issued,  the cost of quality control personnel  equipment is reflected in the quotation, which is also an implicit boundary between the high  low quotations of different CNC machining manufacturers. Robot components have strict requirements for form  position tolerances,  lack precision testing. The parts look the same in appearance, but when assembled onto the entire machine, there may be excessive fit clearances.

5、 Delivery, after-sales,  order volume affect unit price

Batch: The quotation for a single sample is much higher than that for bulk orders; Small batch prototype orders result in high cost sharing for fixtures  tooling;

Delivery time: Urgent order processing requires priority production scheduling, resulting in an increase in quotation;

After sales responsibility: Low price manufacturers are only responsible for delivering parts,  do  assume process responsibility for assembly problems;

Reliable suppliers can conduct DFM process evaluations in advance, identify drawing process risks in advance,  cooperate with subsequent assembly issues for review. This part of the technical service cost is also included in the quotation,  robot processing manufacturers who value long-term service are more willing to invest here. Shenzhen Huiwen Zhizao specializes in CNC machining of robots, focusing on CNC precision machining of robot components. Equipped with 370+processing equipment  IATF16949 certification, we specialize in five axis  turn milling composite machining of 7075 aluminum alloy  other materials. We can provide one-stop services for customers in the robotics industry, including design, intelligent manufacturing,  assembly. DFM process evaluation can be conducted in advance to avoid potential processing risks in the drawings  ensure the consistency of dimensions of robot structural components, thin-walled shells, force feedback handles,  other parts.

Frequently Asked Questions Q&A

Q: What content should be prioritized for comparison when receiving multiple CNC quotations with significant price differences?

A: Priority should be given to verifying raw materials, processing equipment types, testing methods, surface treatment specifications,  tooling cost allocation, rather than just comparing individual unit prices.

Q: Should we prioritize low-cost CNC machining during the robot prototype stage?

A:  recommended. The precision  deformation control of robot CNC machining in the prototype stage directly affect the overall debugging of the machine,  low-cost solutions are prone to repeated rework, which delays the project cycle.

Q: What is the help of DFM evaluation in controlling processing costs?

A: DFM process evaluation can optimize difficult to machine structures in advance, reduce thin-walled deformation,  lower processing hours. While ensuring accuracy, it can reasonably compress costs, rather than simply reducing quality.

In summary, the difference in CNC machining quotes for robots with the same drawings is  due to differences in the appearance of the parts, but rather a comprehensive difference in equipment grade, material quality, process route, testing standards,  supporting technical services among different robot machining manufacturers. Purchasing selection should  only compare prices, but also align with the full set of technical specifications to avoid greater losses such as assembly failure  project delays caused by low-priced parts. Welcome to provide drawing consultation. We can provide 2D drawings, 3D models,  technical requirements to obtain DFM process evaluation  itemized quotations.