Perpetual motion machine

Perpetual motion machine
Perpetual motion machine remains a dream unattainable.

 

As a manufacturer, APPORO has quite an understanding of design of machine tools and the way they work. We figure how to optimize our CNC manufacturing procedures and to enhance the efficiency all the time, so as to reduce the manufacturing costs. Hence, when knowing there is so-called machine design which could conserve energy or enhance efficiency, APPORO surely looks into its operating principle in details and evaluates if it matches its advertised performance. Not surprisingly, the actual test result often falls short. Speaking of that, several well-known scams in history also adopted this kind of conceptual design, claiming to have created perpetual motion machine(*Ref) to defraud.

 

What is a Perpetual Motion Machine?

Perpetual motion machine refers to a machine that does motions constantly and works without energy input. There are two major categories in terms of perpetual motion machine. The first kind violates the first law of thermodynamics as it does work without energy sources. The first law of thermodynamics states conservation of energy, indicating the total energy stays constant in an isolated system, and that no extra energy emerges in that system. Any machine that claims to produce energy from nowhere falls into this category.

While the first kind of perpetual motion machine was proved to be impossible, discussions about the second kind of perpetual motion machine were put on table right away. Its design makes use of the energy outside of the isolated system such as heat and wind energy, striking the balance so that the system could operate perpetually. However, energy would eventually be exhausted from the working machines. The just balance could only be reached if there is energy input, so it still failed to forever motion without additional energy.

 

After Perpetual Motion Machine

The idea of perpetual motion machine has existed for centuries. Based on the scientific understanding nowadays, it remains a dream unattainable. However, there are still a lot of “scientists” engaged in the invention of perpetual motion machine, one after another. Basically these “scientists” are:

1.) Rookies: They barely know a thing about the concept of perpetual motion machine. They often mistake certain device for perpetual machine, which, in fact are device that absorb energy in the dark. For example, human body.

2.) Genuine scientists: They hold the firm belief that science has to be challenged all the time, thinking that thermodynamics could also be wrong or should be revised, as Newton’s law of motion was revised by theory of relativity quantum mechanics. It is never easy to overthrow a law, but their attitudes are admirable. These people are the most likely to invent perpetual motion machine.

3.) Fraud: Even in this era of information explosion, we can still see those who claim to have invented perpetual motion machine. They use sophisticated physics terms and fancy words to convince other to take their scientific results and defraud them of investment. But, until now, all perpetual motion machines are proved to be fraudulent.

 

Will The Dream Come True?

Perpetual motion machine has always been the dream in the field of science. Just like alchemy for development of chemicals, as many efforts are put into this probably impossible techniques, many relevant techniques are then created. As a pragmatic CNC manufacturer, although we might not believe the concept perpetual motion machine would be ever realized, we could not deny the fact that the progress of science and mechanic design derives from the constant efforts of researchers. Holding the same attitude, APPORO will non-stop updates and introduces new techniques and shares more case studies, hoping to have in depth academic exchange and to contribute to the manufacturing field.

 

*Ref: Learn more about Perpetual motion.

Design Matters (Part 4) – Uneven sheet materials

Uneven sheet materials
Too thin of too thick, uneven sheet materials can be a huge problem.

 

Generally speaking, when it comes to deciding the thickness of sheet materials, the unevenness is often a concern. It then becomes necessary for the sheet materials to have additional thickness, so that we can machine the materials to the required dimensions and at the same time ensure the accuracy of the reference surface and the relative dimensions. Whether the sheet materials are rolled metals or extruded plastics, they all need molds for manufacturing purpose. However, mold precision goes down with time, which could lead to the poor quality of the sheet material surface, as well as the uneven material thickness.

 

Case Study on Uneven Sheet Materials

Recently, APPORO machined a batch of panels by milling, of which mostly are Eurorack & Modular Synthesizers, and delivered them to our Japanese customer. After assembling the panels, they found out the assembly acrylic plates were not completely coplanar with the panels, and turned to APPORO for solutions. APPORO digged into the situation and then figured out it was due to the uneven thickness of the acrylic plates, which resulted in the height gap between the metal panels and the acrylic plates.

 

The uneven thickness of the acrylic plates resulted in the height gap between the metal panels and the acrylic plates.
The assembly acrylic plates were not completely coplanar with the panels due to uneven thickness.

How We Solve Unevenness?

The panels are 1.6mm thickness steel plates with drilled holes, milled grooves, and after powder coating. While the acrylic plates are 3.0mm thickness amber transparent acrylic, of which the outer areas were to milled into 1.4mm in height. Usually, the rest areas with extra 1.6mm lump of the acrylic plates could perfectly match the steel panels. However, only few suppliers provide amber transparent acrylic, and therefore the quality and precision of the molds are not satisfying. Consequently, those so-called materials with 3.0mm thickness are actually with thickness around 2.6-3.2mm, which are of considerably unstable quality. What’s more, even we can find the inconsistent thickness across one plate. After the discussion, our customer agreed to accept the panels with the 1.5-1.8mm gap between the unmilled and the milled surfaces. So, APPORO offered the solutions below for this problem:

1.) Cut the materials into plates from the 3.0mm thickness acrylic sheet materials. Then, checked the thickness of every sheet material, and eliminated the materials with thickness less than 2.70mm and over 3.0mm.

2.) Milled the parts into 1.2mm in height, with at least 1.5mm to 1.8mm lump on the top. So, after the assembly the acrylic sheet might be 0.1mm lower than the panel surface, which could still meet the assembly requirement of the customer.

 

Finally, the technical team of APPORO conquered the difficulties in production, assembly, and etc., helping our customer deal with the tricky situation. Again, APPORO won the trust of our customer and also the opportunities of further cooperation. If you are undergoing similar problems during design or assembly process, send us an email for the technical discussion with APPORO. APPORO will assist you of advancing in the product design.

 

Learn more about the importance of design in CNC manufacturing:

Design Matters (Part 1) – Shrinkage

Design Matters (Part 2) – Coating

Design Matters (Part 3) – Warping

Burr and Deburr

Burr and deburr
Burr and deburr

We probably all heard about this old saying in our lives: “To err is human, to forgive divine.” Of course we are not going to talk about making mistakes and forgiving people here. It is that the saying perfectly matches the topic we are about to discuss this time: burr and deburr. A burr refers to a small piece of material left on the part after processing. No matter what manufacturing method we are using, burrs sometimes are inevitable. Take die casting parts for example, burrs are likely to form on the shut-off surface. Besides, drilling can also result in burrs around the hole.

 

Why we have to remove the burr?

Even though it is small, a burr can possibly result in functionality problem of a workpiece, assembly failure, and even injury of assembly operators or customers. Especially for some parts the surface is extremely critical, burrs will not be allowed. In that way, deburring process will be necessary. Therefore, how to remove the burrs without harming the functionality of the parts then reflects the techniques of a manufacturer.

 

Generally, there are 5 kinds of different deburring methods: manual, electrochemical, thermal energy, cryogenic, and mechanical. Among these 5 methods, manual deburring is most common process as it is more cost-effective. Here, APPORO has a case study on manually deburring the die casting parts.

 

Case study on deburring the die casting parts

There is a zinc die casting project that APPORO has been cooperating with one customer on for several years. According to the drawing of this item, there is a hole with slope end on the shut-off surface. So, this design increases the possibility of having burrs on its edge. Because APPORO already noticed that situation, when we moved to the mass production process, we always examined every part carefully and removed the burrs on it. The customer has always been content with the quality all this time.

 

To remove the burrs by chamfering
Burrs were aroound the end of the hole

 

However, recently the customer placed an order of these zinc die casting parts again. After the die casting process, we used tumbling to remove the burrs, and then reamed the parts so the dimensions could be within the tolerance. However, when we were inspecting the parts, we found out that the parts were still with burrs. Because the burrs were around the hole end, we knew the root cause was that the reamer had already worn down. As a result, we changed the reamer instantly and deburr the parts again by chamfering. The situation was thus well solved. Of course, there was no influence on the quality of these zinc die casting parts. And, eventually, our customer was satisfied with them. APPORO pays attention to every trivial detail, so we can always offer the best quality to our customers.

 

Are you looking for a reliable manufacturer that can help produce your parts without burrs? No matter what needs you have, APPORO will strive to meet your expectations. Contact APPORO for a free project review and get a RFQ today!

 

If you haven’t had the drawing for your project, you can also learn more about: How to Make Your Own CAD Drawing?

Design Matters (Part 3) – Warping

Undoubtedly, part warping is a nightmare for both manufacturers and customers. It can affect the functionality of a part or lead to assembly failure. Generally, part warping is due to residual stress, which can be highly relevant to the choice of materials, dimensions of the part, and manufacturing conditions.

 

Warped part can be straightened.
Warped part is mainly caused by the residue stress of the material

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Design Matters (Part 2) – Coating

Thickness of Coating do play an important role on functionality of the part.
Coating do play an important role on functionality of the part.

Previously on Case Study we discussed material shrinkage as an important factor to be considered in the design before production. Apart from material shrinkage, there are still far more factors you have to be aware of in your design. That being said, devil is in the details. Especially when designing an assembly part, you have to pay extra attention, or assembly failure can be foreseen. Coating then is a topic worth a discussion.

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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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Diamond Knurling Operation on CNC Lathe

Knurling is to feature patterns onto the CNC machined components.
Knurling is to feature patterns onto the CNC components.

As mentioned previously in “Cross Knurling Profile DIN 82-RGV”, knurling is a manufacturing process to feature straight, crossed, angled, diamond-like lines or pattern onto the CNC components. Usually, we use DIN 82 knurling specification standard for most CNC machining cases. If diamond knurling is required, we shall use DIN 82-RGE which is featured with diamond-like 30° cross male knurling. Also, we may consider DIN 82-RGV which is featured with cross knurling pattern as an alternative for customized purpose.

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Effects of CNC Machining on Part Distortion

With recent increase in demand for more ultra precision machining designs for improving performance requirements, we are facing a great challenge in this kind of CNC machining services. Generally speaking, the greatest challenge when machining these components is part distortion. For instance, removing material up to 80 % on CNC machines to produce monolithic components replacing multi part assemblies has become common in aerospace, automobile, precision instrument industries. These kind of components might have similar appearance features such as thin wall, very long length, etc.

What Is Part Distortion?

Part distortion is defined as the deviation of part appearance from original shape after released from the fixture. Generally speaking, distortion could come from several variables such as type of material, inherent residual stresses in bulk material, residual stresses induced from CNC machining, part design, etc. In the most cases, the dominant factor of part distortion is the inherent residual stresses in the part. In general, these inherent residual stresses usually come from different manufacturing processes, i.e. quenching, stretching forging, extrusions, casting, welding, machining, forming, and etc.

CNC Machining Part Distortion
Residual stresses induced from CNC machining may cause parts deforming.

 

How Can I Minimize Part Distortion?

Distortion is a common challenge in manufacturing industrial components. The suggestions to minimize or eliminate distortion shows as below:

1.) The length to thickness ratio of the part design is lower than 10:1.

2.) Pre-heat treating the metal part prior to manufacturing for stress relieve. For instance, the general stress relieve condition for AISI 4340 alloy steel is at 650-670°C for 2hrs, slow cooling furnace.

3.) As per our experience of CNC machining service, distortion increases with the cutter size at constant feed, speed, depth of cut and material removal rates.

4.) Considering that WEDM process involves being fully-submerged, it imposes nearly no stress on the metal part.

 

With optimized manufacturing process flow, we are able to minimizing any deformation on all the CNC machined parts. Also, to select the suitable cutting tools and CNC machining parameters is of utmost importance. Note that the choice of cutting tools size is key to strike the balance between the productivity and geometrical constraints of the component. By the way, you can learn more about:

1.) Larger Corner Radii Reduced CNC Machining Cost

2.) 4 Things That Will Impact Your Manufacturing Costs

 

 

Shrinking and Distortion in Deep Slotting Parts

Parts after machining, cold rolling and welding usually generate internal residual stresses which may result in serious and unacceptable shrinking or distortion. Whatever the parts are made of metal or plastic. Recently, we are running a CNC machining project of rotor shaft for our Singapore client. At current, this project is still in First Article status. The rotor shaft is part of motor assembly which basically includes a rotor shaft and motor shaft. The motor shaft will be inserted into a deep, accurate, diameter Ø5 H7 (+0.012/-0mm) hole on the rotor shaft. There is a deep slotting cut for enlarging the hole when assembling. However, after deep slotting, the hole size will be slightly reduced and also out of tolerance which lead to a complaint happened. Our customer was using pin gauge 5mm to check the hole. When checking, the pin gauge must go all the way till depth 18.0mm, but failed.

 

CNC machining Rotor Shaft, shrinking may happen after deep slotting.
The rotor shaft shrinking after deep slotting

 

Root Cause for Shrinking Parts

In the meantime, after inner discussion, we believe that the downsize hole was caused by internal residual stresses. Prior to slotting, we had full inspection that the diameter 5mm pin gauge could go all the way as it is indicated in the drawing. In that way, we list two possible reasons for the situation below:

  1. The drawing says the internal hole is Ø5 H7 x 18mm, and we did machine the hole into 18mm in depth accordingly, even into 18.5mm.
  2. Besides, the internal stress would be very likely to lead the hole to slightly shrinking after slotting. Then, it will be unreasonable to meet the tolerance H7 standard after slotting. We suggest our customer to insert the pin gauge harder. So, it will not be a problem for the pin to go into the internal hole.

 

In conclusion, as the dimension was machined exactly based on the drawing, we think the situation is taken full control of by us.​Therefore, We recommend our customer to move forward to the mass production.​​

 

If you have similar design with deep slotting, send your 2D and 3D drawing files to our international team of engineers for a free quote. We look forward to cooperating with you. Please check our RFQ process and send us email.

4 Things That Will Impact Your Manufacturing Costs (Part 2)

A few days ago, we have talked about various factors which may affect your manufacturing costs in previous article. In short, material costs are directly relative to part quality and durability. And, surface treatment costs have significantly increased recently due to strictly environmental policy. No doubt, if you are working out a CNC machining project, APPORO can help you figuring out the manufacturing cost accordingly. Learn more about: How To Work With APPORO

Apart from the above two factors, there are still others which can affect your manufacturing costs:

3.) Manufacturing Process

Generally speaking, the slower the machining process is, the much higher precision is. For example, WEDM(Wire Electrical Discharge Machining) is one of the slowest metal machining process in the world. A series of rapidly recurring current discharges between two electrodes cut the profile of bulk material. Mostly used for stamping die cutting and prototyping which required high accuracy quality.

Furthermore, the complexity of design do play an important role in manufacturing costs. High challenge designs usually require cutting-edge machining facility for optimized quality. However, the investment in high-end machinery will also increase the cost of your project. Though, the advanced equipments can provide a great machining experience.

4.) Lead Time of Your Project

If you need a time effective production run, this can impact the cost depending on the project. To manufacture a project quickly is much more costly than a longer lead time. You may wonder what factors do have impact in a fast lead time project. Generally speaking, there are usually various necessary procedures prior to part manufacturing. For instance, to arrange CNC machines and engineers from mass production lines, to prepare customized jig and tooling. Urgent project results in much more impact from general mass production runs. In contrast, a longer turnaround can usually minimize capacity losses.

Customized Jigs and Tooling used in quickly manufacturing processes
Customized Jigs and Tooling

Get A Quote For Your Next Project

Via above various factors, a CNC machining services manufacturer can evaluate a quote your project. At APPORO, we can provide you with a competitive price. Pls send us your RFQ to get a free quote. Our production lines can offer a wide range of manufacturing processes to support your inquiry.