Design Matters (Part 1) – Shrinkage

Shrinkage is a physical phenomenon mostly happening to molding parts made by plastic injection and die casting.
Shrinkage is a physical phenomenon mostly happening to molding parts.

It is always exciting to carry out new projects. However, before moving on to the production process, you have to make sure that your design already includes all the factors that might have influences on your parts. This time, APPORO would like to share with you how material shrinkage happens, and how it can affect your parts.

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4 Things That Will Impact Your Manufacturing Costs (Part 1)

So far, to exactly predict machining time and manufacturing costs can be very difficult. For instance, factory location, facility or even politics do have impact on the quotes of manufacturing. Sometimes, to request a quote for your manufacturing project feels like looking for a needle in a haystack. In fact, you can still have an initial concept of cost even without 2D and 3D CAD drawings.

Various factor which have impact on manufacturing cost for CNC machining services
Top-end CNC machinery can manufacture high quality parts.

 

 What is included in Manufacturing Costs?

Generally speaking, there are various factors which directly have impact on the cost of CNC machining services. For instance, materials used, dimensions of the part, quantity per batch, manufacturing process applied, post processing used. Furthermore, auxiliary processing equipment can also affect the cost of manufacturing project such as customized cutting tools, jigs and tooling. In spite of above, there are still some basic guidelines which will have impact on your project. Hopefully, this can be grateful for your evaluation in early planning stage.

1.) Material Costs

Obviously, different type of material costs are largely various from each other. Nowadays, material cost is getting more transparency of pricing due to freely global trading. You can get a roughly idea of material cost by looking for local price for raw material. Furthermore, parts made of cheaper material is likely lack of durability or poor quality compared to high-end material. However, parts made of high-end material usually means more manufacturing lead time for good quality.

Manufacturing costs is relative to many factors.
Various factors may affect your manufacturing costs.

 

2.) Surface Treatment Costs

Surface treatments are generally for cosmetic and anti-rust purpose. In the past, the chemical solution used in most of surface treatment process are usually with toxic hazards. Actually, the proportion of surface treatment cost in total manufacturing cost were not so high. Nowadays, the directive of RoHS(*Ref.1) has strictly restricted these hazardous substances. At the same time, surface treatment costs are getting higher due to stricter environment policy. For a roughly estimation, the heavier the weight, the more expensive the surface treatment cost.

Surface treatment may cost more nowadays.
Surface treatment: Anodizing

 

Learn more: 4 Thing That Will Impact Your Manufacturing Costs (Part 2)

 

*Ref.1: See more about the directive of RoHS

Reverse Engineering: From Real Component to Print

Reverse engineering, so called back engineering, is to get the design information from the item already made. Afterwards, to reproduce the item total according to the obtained information. Laser scanner, CMM, profile projector, industrial CT scanning are the most powerful measurement tools for reverse engineering. Furthermore, you can refer to Wikipedia for more understanding about reverse engineering.

At APPORO, we provide reverse engineering service for parts made by CNC machining, stamping, plastic injection, die casting. Generally speaking, we use CMM and profile projector to extract the dimensions accurately from the original workpiece. Below showed a CNC machining service project for our USA client who were asking reverse engineering for Rotary Tattoo Machine components.

Original Sample of Rotary Tattoo Machine Components from USA client
Original Sample of Rotary Tattoo Machine Components

Reverse Engineering Step by Step

1.) To extract the sample dimensions by CMM, profile projector and Venier caliper.

Original samples sent from USA client. Firstly, sent for extracting all the dimensions by CMM, profile projector and Venier caliper. After that, all the dimension information are to create 3D CAD drawing for further CNC machining process. See more about our quality inspection instruments.

Reverse Engineering: Rotary Tattoo Machine - Frame dimensions extracted by CMM
Rotary Tattoo Machine – Frame

Material: Aluminum Alloy 6061-T6

Surface Finish: Red, Black and Silver Anodizing

Type: CNC Milling

Reverse Engineering: Rotary Tattoo Machine - Motor Housing Cap from USA Client
Rotary Tattoo Machine – Motor Housing Cap

Material: Aluminum Alloy 6061-T6

Surface Finish: Red, Black and Silver Anodizing

Type: CNC Milling

2.) From 3D to 2D prints for CNC machine programming

Generally speaking, to convert 3D CAD drawing into 2D CAD print is a must for CNC machine programming. A CAM software can both read and output CNC programming code for production from 2D prints. After that, we will confirm with customer by using the 2D CAD prints marked with dimensions and detailed descriptions. How to make a good 2D CAD print? For instance, various but less view sides of workpiece, detailed but simplified dimensions, marked with important notes if any. After intensive discussions with client, we have reached a consensus to integrate frame components into one part as below.

CNC Machining Services: Rotary Tattoo Machine - Frame for CNC machine programming
Reverse Engineering: Frame

 

CNC Machining Services: Rotary Tattoo Machine - Motor Housing Cap for CNC machine programming
Reverse Engineering: Motor Housing Cap

 

3.) Move to production

At last, the customized jigs, cutting tools and CNC programming were ready for production arrangement. You can visit our website for more understanding about our core service. After CNC machining, the items were sent for with high quality anodizing.

CNC Machining Services: Rotary Tattoo Machine Frame
Frame with Glossy Red Anodizing

 

CNC Machining Service: Rotary Tattoo Machine Motor Cap
Motor Cap with Glossy Black Anodizing

 

APPORO are still working closely with our USA client for cases with innovative new design, whilst improving the cosmetic surface with clear machining action. Do not hesitate to contact us should you have any interesting cases. We look forward to cooperate with you.

Aluminum Anodize Coating Failure

Aluminum anodizing is to produce oxide layer on the surface of aluminum parts to improve the capability of anti-corrosion. Actually, we had talked about this topic in previous case study. But, in this topic, we are talking about aluminum anodize coating failure. The failures caused by various issues on a aluminum CNC machining part generally fall into some of the following categories:

1.) exposure to chlorine based solution

Chlorine is very reactive and causes pitting corrosion by removing the oxide layer. Be careful if Chloride ion in a sulfuric acid electrolyte exceeding a critical level of chloride of 80 ppm. Please also notice that chlorine based solvents are for degreasing which may also cause acid pitting.

2.) exposure to very acid or alkaline solution

Solutions, pH lower than 4 or higher than 9, has the ability to break down the oxide layer and make the underlying aluminum susceptible to corrosion. Generally speaking, to rinse completely the aluminum anodize part is the most satisfactory method of eliminating this problem.

Blind holes v.s. anodizing failure

The anodizing failure rate can be high if your CNC aluminum parts featured with blind holes. If the high acidity anodization solution are not well removed from the blind holes, the liquid will flow out and damage the surface of CNC aluminum parts resulted in flaking-off and spots on its anodiizing surface.

 

Below photo showed an aluminum CNC milled part etched by acid residues. The white, dirty, flaking off oxide powder surrounding the threaded hole is gradually getting worse if no further action against it.

Aluminum anodize can be failure on occasion.
Aluminum anodize failure because of acid.

 

Preventive action to against failure of aluminum anodize

As described above, to rinse and clean the blind hole on a CNC aluminum anodize part is the best way to remove acid solution. It is a MUST to take this preventive action to against failure of anodizing.

 

Should you have any questions about aluminum anodize or other RFQ, feel free to send us RFQ for project reviewing.

Inner Thread Machining by Using Fluteless Tap

There are many ways for thread drilling in metalworking. As for external thread, both thread rolling and thread dies are most common used. As for inner thread machining, we generally use taper/second/bottoming three steps thread tapping or fluteless tapping.

Frankly speaking,  to drill a deep and small inner thread on high hardness or malleability raw material is a difficult mission. Thread machining is all about factors. Such as hole diameter, the forming speed and types of drill bet on the responses: torque, hardness, feeding rate, and thrust force of the form tapping process. Fluteless tap is the one of the best tooling for machining inner thread on CNC turning machines.

Fluteless tap thread machining
Thread machined by using fluteless tap

 

What is the Advantages of Fluteless Tap?

Fluteless tapping, so called form tapping. The screw thread is formed by plastic deformation of a working metal under high level of torque. And, well monitored operation processing to avoid tool bit breakage when thread machining.

Fluteless tapping can form a perfect screw thread with no waste material in a pre-drilled hole. Besides, it is kind of opposite style of external thread rolling method. The inner screw thread machined by fluteless tap is with higher strength and less error of pitch diameter. So, we mainly use fluteless tap machining inner thread on aluminum part, brass part and zinc part when in CNC precision manufacturing.

 

Thread Machining in Industrial Application

Let’s consider automobile industrial application as an example. Mechanical components need to have threaded parts allowing quick and precise assemblies and dis-assemblies. The engine heads manufactured with non-ferrous metals have a excellent capacity to deform and maintain an acceptable mechanical strength. As a result, thread formed by fluteless tapping can guarantee perfect full threading and high tensile strength.

 

Inner thread formed via fluteless tapping
Zoom in on the inner thread of cut part

 

However, inner thread machined by fluteless taps have some peculiarities. For example, the appearance of a split crest on the top of the thread. Above phenomenon is directly rely on the initial pre-drill hole diameter. In addition, the smaller the inner diameters, the slighter the split crest on the top of the screw thread after flutless tap forming.

 

the appearance of a split crest on the top of the thread
Split crest on the thread

 

Feel free to ask us if any questions about fluteless tap on CNC precision machining parts. Pls send us your RFQ for free project reviewing.