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  4. Hi mates, I need some help in a project. In short, I have a part of a mechanical assembly, and this part broke due to material failure. I need to propose a solution only by changing the material, not the desing (at least, the main focus have to be only change the metal...). This is an axle from a BMX jump bike, it failed on me suddenly. Actually, I didn't realize at the moment that it broke into 2 pieces. A friend of mine asked for the bike and I gave it to him, he jumped in and asked what's wrong with the front hub since it was like "loose"... The nuts were in place, all seemed fine but it really had a little gap. When we were loosening the nut, we realized that we had two separate pieces of the axle, lol. Here are some amplified images of the axles and the fractures from the two perspectives. I noticed that the failure started right in the last thread of the axle, meaning that it had stress concentration caused by the thread cavity. What information can you deduce when looking at the fracture? The axle is made of Chromoly (I think it's 4130 or 4140 Cr-Mo, correct me if I'm wrong). The diameter (almost uniform along the axle) is 3/8" of an inch (around 0.95 mm). The total lenght of the axle is around 16.25 mm = a little bit more than 5/8 inch. I will attach a diagram to show up what's the situation. The words are "gancho"=dropout, where the fork of the bike sits the axle. "Apoyo rodamiento" = where the bearing seats on the axle. The distance (c to c) of the two sites is 18.5 mm = almost 3/4 inch, so I assume that there's some bending involved due to the separation, and it's not only shear stress. There's also a lot of fatigue because of the abusive nature of BMX tricks (mostly street BMX tricks, when you ussually land tricks with your bike from more than 5 ft). Looking at the image where the 2 pieces are, we can see the threaded piece and at left there's the another one, the mirror-like polished site right there is where the bearing sits (it's a sealed catridge bearing). The fracture occured closer to the bearing seat, on the first thread like I said before (stress concentration?)... Images at https://filebin.net/6j8yeglbvyylqgwg Thank you in advance for any reply! Matt.-
  5. Can an engineer, review and stamp plans prepares by someone else?
  6. Is there any Job for fresher btech mechanical 2016 passout

  7. Earlier
  8. There is a vide range of bearing blocks readily available in the market, if the required design doesn't falls in that, prepare detailed manufacturing drawings of all the parts and get it made from the supplier. After all any machine is an assembly of standard bought out parts, manufactured parts and hardware.Bill of materials to prepared first.
  9. Does anyone know what the principle of the work is a valnut cracking and shelling machine, how they work, does anyone have any drawings about it. For example, like the ones in the picture
  10. I'm facing this problem from a very long time. Let's say you founded a Patent/Design that fits perfectly for your needs. Now the problem is how can you realize that design? ( Design in Solidworks is ready but physically it's not ) How can you make from a block steel to the required machine? I know that has to happen using milling machine, lathe and other different types machines and processes but what's the exact procedure? How the marking has to be done? Any books or documentation about this? I know that this is vague but there should be something about this. Eg. Let's say a bearing block. How that has to be made ?
  11. 304 stainless steel and 316 stainless steel—What’s the difference?

    Selecting the best grade for stainless steel investment casting can mean longer lasting performance, especially in challenging corrosive environments.304 and 316 are the two of the most widely used stainless steel casting grades in the world. For 304 stainless steels and 316 stainless steels,There is no such definition of “which is good” because different stainless steel materials have different uses.The difference between 304 stainless steel and 316 stainless steel is as below.

    1-Different chemical composition:

      304 is Gai’s stainless steel . Its material composition is OCr18Ni9. 304 Stainless steel: C ≤ 0.08 Ni 8.00 to 10.00 Cr 18.00 to 20.00, Mn <= 2.0 Si <= 1.0 S <=0.030P <=0.035.

      316 is Austenitic stainless steel.The material composition is OOCr12Mo2Ti. 306 Stainless steel C≤0.08 Ni10.00~14.00 Cr16.00~18.00, Mo2.00—3.00 Mn<=2.0 Si<=1.0 S<=0.030 P<=0.035 And 306L stainless steel C≤0.03 Ni10.00~14.00 Cr16.00~18.00, Mo2.00—3.00 Mn<=2.0 Si<=1.0 S<=0.030 P<=0.035.It is a low carbon stainless steel with titanium-containing, resistant to alkali and acid (except medium containing chloride ions).

      The Big difference between 304 and 316 is that 306 stainless steel has 2-3 more nickel than 304 stainless steel.

      304-vs-316-stainless-steel

      2. Performance is different:

      304 steel can resist corrosion by sulfuric acid, phosphoric acid, formic acid and urea. Applicable to general water, control gas, wine, milk, CIP cleaning liquid and low occasions or no corrosive materials.

      The 316L steel grade adds molybdenum based on 304 Steel. It can significantly improve its resistance to intergranular corrosion and oxide stress corrosion. It also reduces the hot cracking tendency during welding. It also has good resistance to chloride corrosion.

      It is often used in applications of pure water, distilled water, medicines, sauces, vinegar, etc.With high hygienic requirements and strong media corrosion resistance.The price of 316L is almost twice than 304.

    On Mechanical properties: 304 is better than 316L. Because 304, 316 has excellent corrosion resistance and heat resistance. It is widely used as stainless steel. 304,316 has similar strength and hardness.

      The difference between them is that the corrosion resistance of 316 is much better than 304. The more important point is that molybdenum metal is added to 316. The molybdenum metal can improve its heat resistance prosperity.

      3. Different maintenance methods:

      We can use electroplating or oxidation-resistant metals to ensure the carbon steel surface, but this protection is only a film. If the protective layer is destroyed, the underlying steel begins to rust.

      The corrosion resistance of stainless steel depends on the chromium element. When the amount of chromium added reaches 10.5%, the atmospheric corrosion resistance of stainless steel will increase significantly. But if the chromium content is higher, it still can improve certain corrosion resistance. But not obvious.

      The reason is that this treatment changes the type of surface oxide to a surface oxide like that formed on pure chrome metal. But this oxide layer is very thin. Through it, you can directly see the natural luster of the steel surface. To give stainless steel a unique surface.If the surface is destroyed, the exposed steel surface will react with the atmosphere. This process is actually a self-repairing process. Re-forming this passivation film can continue to protect.

      Therefore, all stainless steels have a common characteristic. The chromium content is above 10.5% and the preferred steel grade also contains nickel. Such as 304 .If the addition of molybdenum can further improve atmospheric corrosive. Especially against chloride-containing atmospheres. That is 316.

    What is the 304 Stainless Steel Types and Applications?

    304 Stainless Steel Types Different Applications
    Stainless Steel 304 (S30400): 
     
    Low-carbon modification of type 302 for restriction of carbide precipitation during welding. Chemical and food processing equipment; brewing equipment; cryogenic vessels; gutters; downspouts; flashings.
     Stainless Steel 304L (S30403): Extra-low-carbon modification of type 304 for further restriction of carbide precipitation during welding. Coal hopper linings; tanks for liquid fertilizer and tomato paste.

    What is the 316 Stainless Steel Types and Applications?

    316 Stainless Steel Types Different Types’ Applications
      Stainless Steel 316 (S31600): Higher corrosion resistance than types 302 and 304; high creep strength. Chemical and pulp handling equipment; photographic equipment; brandy vats; fertilizer parts; ketchup cooking kettles; yeast tubs.
     Stainless Steel 316L (S31603): Extra-low-carbon modification of type 316 Welded construction where intergranular carbide precipitation must be avoided. Type 316 application requiring extensive welding.
     Stainless Steel 321 (S32100): Stabilized for weldments subject to severe corrosive conditions, and for service from 800 to 1600 F. Aircraft exhaust manifolds; boiler shells;process equipment; expansion joints; cabin heaters; fire walls; flexible couplings, pressure vessels.

      We are a professional stainles steel foundry in China with 22 years history.We can make all types of stainless steel castings, not only limited to 304 and 316, but can also make stainless steel investment castings with other grades, such as PH17-4, CG8M, 2205, ect. Any project or product about stainless steel casting, welcome contact us freely.

  12.   We are the lleading investment casting foundry for various metal components in 1997. And we have started our exporting business all over the world.Such as American, Japan, German,Australia, UK, Canada,ect.

      Currently, our investment casting company has 2 units: one is foundry,Another one is CNC Machining Factory.There are total 310 workers in our factory, with 265 workers, 7 engineers, 23 QC man, 10 sales person, and 5 management.Via many years’ hard working,we are now have become one of the largest investment casting manufacturer and supplier

  13. Dear Alban, Absolute symmetry is truly rare. Consider the case of a table on four legs of equal length. By your argument, all four legs each carry 1/4 of the total weight. Everything is perfect, the floor is level, the table is flat, the legs are all equally long. But now enter a tiny bit of reality (ever so slightly!). One of the legs is short by 0.0001 mm. To the eye, it appears that perfect symmetry still exists, but in actual fact, one of the four legs no even longer touches the floor. Do you still think that each leg in contact with the floor carries only 1/4 of the weight? What holds up the remaining quarter of the weight? DrD
  14. Hello, in some cases you may circumvent the problem of solving a statically indeterminate system, if symmetry exists. In the ideal case of a table you have quarter symmetry, what makes it easy, to determine the leg forces. However, you have to be able to identify existing symmetry. In other cases solving the problem may be simplified by the existence of some guiding equipment. Regards Alban
  15. The effect of several hot pressing parameters on the internal mat environment was investigated by using the mathematical model and the results were compared to data collected experimentally. The different pressing parameters included three initial mat moisture contents (5, 8.5, 12 %), three final panel densities (609, 641, 673 kg/m3 or 38, 40, 42 lb/ft3), two press platen temperatures (150, 200 °C), and three press closing times (40, 60, 80 s). The variation of temperature and total gas pressure during the press cycle at six points in the vertical mid-plane of a single layer, random mat structure was predicted with the heat and mass transfer model using the different pressing conditions. Twenty-four boards were manufactured according to the same specifications, and the temperature and internal gas pressure were measured with thermocouples and gas pressure probes at the same six locations. The model predicted data described the major trends during the hot-compression operation qualitatively. However, further work is needed to make quantitative predictions. A hot-compression model was developed based on fundamental engineering principles. The material physical and transport properties were the best available values from the literature or best estimates based on engineering judgment. A sensitivity study assessed the relative importance of the different transport properties during the hot-compression process. The response of selected variables of the hot-compression model for a perturbation of the parameter values was investigated. The sensitivity analysis of the model parameters revealed that the thermal conductivity and gas permeability of the mat have the greatest influence on model results. The assessment of these transport properties experimentally, as a function of mat structure, is highly desirable and can considerably improve the model predictions. EFFECT OF HOT PRESSING ON THE INTERNAL MAT ENVIRONMENT.pdf
  16. Very little investigation has been carried out to study the performance of flat heat pipes, though researchers recently turned their attention to the same. The results of the literature review on heat pipes indicate the necessity and scope for further theoretical and experimental studies on flat rectangular heat pipes. The present work is an attempt to study the steady state operation of the flat rectangular heat pipes, both theoretically and experimentally. It also aims at the study of the influence of the amount of working medium and wick porosity on the performance of heat pipes. Heat Transfer and Fluid Flow Studies on Flat Heat Pipes.pdf
  17. Are you looking for a drive or a motor? If you're looking for a drive, maybe look at the GV3000 series from Reliance Electric. They are variable voltage variable frequency power inverters with output currents ranging from 2 to 360 amps. Various models can be seen here. Hope this helps. M
  18. ChineseSpare.com is an e-commerce platform which is integration of Chinese spares sales and engineering services. China spare parts, products Manufactured in China. Since its establishment, relying on the Middle East countries’ engineering projects, we have mainly exported a large number of mining spares and on-site technical services support, such as Saudi Arabia, the United Arab emirates and other countries. Meanwhile, in the aspect of mining machinery spare parts, we have rich experience in export and transportation. We also have a deep cooperation and keep in good relationship with many domestic large-scale machinery manufactures and foreign well-known factories, distributors and agencies.

    Considering about our customers’ purchasing needs, saving the delivery time, reducing management cost, we build and supply the E-commerce platform. Now we have nine types of products: General Mechanical Parts, Machined Parts, Mechanical Equipment & Assemblies, Electronic Driving, Electronic Components, Process Control & Instruments, Materials, Engineering Services and others. In order to provide more convenient, thoughtful, high-quality services for our customers, we set up the branches in China, Singapore and Middle East. Thanks for your inquiry.

    We abide by honesty as root scrupulously, customer highest, service foremost to satisfy with our customers. We take the business order ”First-class quality, First-rate reputation” and consistently insist on the principle-“customer first” to serve our customers.
    website:www.chinesespare.com

  19. Hello, my dear engineers fellow, I am the manufacturer of waterjet cutting service as our core business in Malaysia. I'm so excited about joining this community hopefully, I could learned and share a lot more in the future. We are the first lady who venturing into waterjet cutting service in Malaysia. Perhaps we can stay connected and growth our networking here. Regards, P.Nazira QURSYTEC.
  20. I think you could stick ultrasonic sensor with the moving part of damper to get accurate feedback and you have various platforms that you could use like : Arduino. But the Damper calculations will be the most difficult part. hope it help you .
  21. Hey guys, I have a project that will involve weighing a tank of water varying from 20-130kg at it's initial value and then monitoring and storing these values over long periods of time like upwards of 4 months. Due to certain restrictions to this project the only method of measurement I can use will need to be by weight. What weight sensor would give me the most accurate weight values whilst being under load for long periods of time without suffering from creep or anything like that? Any advice would be much appreciated.
  22. Hi, So I've now got hold of some new stainless steel screws and they seem to be much more durable. How is it that the other stainless steel screws seemed softer? Is there a test I can do to see if they were aluminium?
  23. This research study has been done in Aljabalein Power Plant at White Nile State. The objective of the study is to compare and differentiate between two types of fuel, light fuel oil (LFO) and crude oil (CRO) used in power plant situated in Aljabalein site. The comparison have been done on different viewpoints including the impact of exhaust gases on the surrounding environment, the performance of engines at different loads, and the operation and maintenance costs. It is found that CRO fuel oil is preferred to LFO fuel due to less operation costs. But it has many disadvantages such as high pollution rates and high consumption of spare parts. Technical and Environmental Study On Using Light Fuel Oil and Crude Oil in Internal Combustion Engines (ICE).pdf
  24. Chemical engineers are accustomed to software for designing processes and simulation. Simulation systems such as Matlab and Aspen Plus are commonly referenced in chemical engineering curricula as required courseware and study tools. Automation professionals are also becoming used to applying simulation to operator training, system testing, and commissioning of plant process control systems. Plant design simulation programs are substantially different from systems used for training and commissioning. Many of the most common plant design simulation programs are steady state, low-resolution simulations that are not usable for automation or plant life-cycle management. SIMULATION AND DESIGN SOFTWARE SYSTEMS FOR TESTING AND TRAINING PROCESS AUTOMATION PROJECTS.pdf
  25. Hydropower is important from an operational standpoint as it needs no "ramp-up" time, as many combustion technologies do. Hydropower can increase or decrease the amount of power it is supplying to the system almost instantly to meet shifting demand. With this important load-following capability, peaking capacity and voltage stability attributes, hydropower plays a significant part in ensuring reliable electricity service and in meeting customer needs in a market driven industry. In addition, hydroelectric pumped storage facilities are the only significant way currently available to store electricity. Water is one of our most valuable resources, and hydropower makes use of this renewable treasure. In managing hydropower, Reclamation is helping the Nation meet its present and future energy needs in a manner that protects the environment by improving hydropower projects and operating them more effectively. REVIEW AND TECHNICAL STUDY OF HYDROELECTRIC POWER GENERATION.pdf
  26. Composite materials have been utilized to solve technological problems for a long time but only in the 1960s did these materials start capturing the attention of industries with the introduction of polymeric-based composites. Since then, composite materials have become common engineering materials and are designed and manufactured for various applications including automotive components, sporting goods, aerospace parts, consumer goods, and in the marine and oil industries. The growth in composite usage also came about because of increased awareness regarding product performance and increased competition in the global market for lightweight components. Among all materials, composite materials have the potential to replace widely used steel and aluminum, and many times with better performance. Replacing steel components with composite components can save 60 to 80% in component weight, and 20 to 50% weight by replacing aluminum parts. MANUFACTURING AND PROCESSING OF COMPOSITE MATERIALS.pdf
  27. The article presents a brief outline of the history of Bajaj rickshaw vehicles industry. Vehicle design, the incorrect usage of petrol and lubricating oil mixture, safety risks in riding rickshaw, and environmental impact were integral activities. Almost all of the engine designers mentioned in the article also were automobile designers, and a few went on to become major manufacturers of automobiles. All of these inventors and more made notable improvements in the evolution of the Bajaj rickshaw vehicles. LITERATURE REVIEW ON THE HISTORY OF BAJAJ RICKSHAW VEHICLES.pdf
  28. Energy conversion engineering (or heat-power engineering, as it was called prior to the Second World War), has been one of the central themes in the development of the engineering profession. It is concerned with the transformation of energy from sources such as fossil and nuclear fuels and the sun into conveniently used forms such as electrical energy, rotational and propulsive energy, and heating and cooling. FUNDAMENTALS OF ENERGY CONVERSION ENGINEERING.pdf
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    • Sateesh Kumar Vaida

      Is there any Job for fresher btech mechanical 2016 passout
      · 0 replies
    • jasonlee

      304 stainless steel and 316 stainless steel—What’s the difference?
      Selecting the best grade for stainless steel investment casting can mean longer lasting performance, especially in challenging corrosive environments.304 and 316 are the two of the most widely used stainless steel casting grades in the world. For 304 stainless steels and 316 stainless steels,There is no such definition of “which is good” because different stainless steel materials have different uses.The difference between 304 stainless steel and 316 stainless steel is as below.
      1-Different chemical composition:
        304 is Gai’s stainless steel . Its material composition is OCr18Ni9. 304 Stainless steel: C ≤ 0.08 Ni 8.00 to 10.00 Cr 18.00 to 20.00, Mn <= 2.0 Si <= 1.0 S <=0.030P <=0.035.
        316 is Austenitic stainless steel.The material composition is OOCr12Mo2Ti. 306 Stainless steel C≤0.08 Ni10.00~14.00 Cr16.00~18.00, Mo2.00—3.00 Mn<=2.0 Si<=1.0 S<=0.030 P<=0.035 And 306L stainless steel C≤0.03 Ni10.00~14.00 Cr16.00~18.00, Mo2.00—3.00 Mn<=2.0 Si<=1.0 S<=0.030 P<=0.035.It is a low carbon stainless steel with titanium-containing, resistant to alkali and acid (except medium containing chloride ions).
        The Big difference between 304 and 316 is that 306 stainless steel has 2-3 more nickel than 304 stainless steel.
        304-vs-316-stainless-steel   2. Performance is different:
        304 steel can resist corrosion by sulfuric acid, phosphoric acid, formic acid and urea. Applicable to general water, control gas, wine, milk, CIP cleaning liquid and low occasions or no corrosive materials.
        The 316L steel grade adds molybdenum based on 304 Steel. It can significantly improve its resistance to intergranular corrosion and oxide stress corrosion. It also reduces the hot cracking tendency during welding. It also has good resistance to chloride corrosion.
        It is often used in applications of pure water, distilled water, medicines, sauces, vinegar, etc.With high hygienic requirements and strong media corrosion resistance.The price of 316L is almost twice than 304.
      On Mechanical properties: 304 is better than 316L. Because 304, 316 has excellent corrosion resistance and heat resistance. It is widely used as stainless steel. 304,316 has similar strength and hardness.
        The difference between them is that the corrosion resistance of 316 is much better than 304. The more important point is that molybdenum metal is added to 316. The molybdenum metal can improve its heat resistance prosperity.
        3. Different maintenance methods:
        We can use electroplating or oxidation-resistant metals to ensure the carbon steel surface, but this protection is only a film. If the protective layer is destroyed, the underlying steel begins to rust.
        The corrosion resistance of stainless steel depends on the chromium element. When the amount of chromium added reaches 10.5%, the atmospheric corrosion resistance of stainless steel will increase significantly. But if the chromium content is higher, it still can improve certain corrosion resistance. But not obvious.
        The reason is that this treatment changes the type of surface oxide to a surface oxide like that formed on pure chrome metal. But this oxide layer is very thin. Through it, you can directly see the natural luster of the steel surface. To give stainless steel a unique surface.If the surface is destroyed, the exposed steel surface will react with the atmosphere. This process is actually a self-repairing process. Re-forming this passivation film can continue to protect.
        Therefore, all stainless steels have a common characteristic. The chromium content is above 10.5% and the preferred steel grade also contains nickel. Such as 304 .If the addition of molybdenum can further improve atmospheric corrosive. Especially against chloride-containing atmospheres. That is 316.
      What is the 304 Stainless Steel Types and Applications?
      304 Stainless Steel Types Different Applications Stainless Steel 304 (S30400): 
        Low-carbon modification of type 302 for restriction of carbide precipitation during welding. Chemical and food processing equipment; brewing equipment; cryogenic vessels; gutters; downspouts; flashings.  Stainless Steel 304L (S30403): Extra-low-carbon modification of type 304 for further restriction of carbide precipitation during welding. Coal hopper linings; tanks for liquid fertilizer and tomato paste. What is the 316 Stainless Steel Types and Applications?
      316 Stainless Steel Types Different Types’ Applications   Stainless Steel 316 (S31600): Higher corrosion resistance than types 302 and 304; high creep strength. Chemical and pulp handling equipment; photographic equipment; brandy vats; fertilizer parts; ketchup cooking kettles; yeast tubs.  Stainless Steel 316L (S31603): Extra-low-carbon modification of type 316 Welded construction where intergranular carbide precipitation must be avoided. Type 316 application requiring extensive welding.  Stainless Steel 321 (S32100): Stabilized for weldments subject to severe corrosive conditions, and for service from 800 to 1600 F. Aircraft exhaust manifolds; boiler shells;process equipment; expansion joints; cabin heaters; fire walls; flexible couplings, pressure vessels.   We are a professional stainles steel foundry in China with 22 years history.We can make all types of stainless steel castings, not only limited to 304 and 316, but can also make stainless steel investment castings with other grades, such as PH17-4, CG8M, 2205, ect. Any project or product about stainless steel casting, welcome contact us freely.
      · 0 replies
    • jasonlee

        We are the lleading investment casting foundry for various metal components in 1997. And we have started our exporting business all over the world.Such as American, Japan, German,Australia, UK, Canada,ect.
        Currently, our investment casting company has 2 units: one is foundry,Another one is CNC Machining Factory.There are total 310 workers in our factory, with 265 workers, 7 engineers, 23 QC man, 10 sales person, and 5 management.Via many years’ hard working,we are now have become one of the largest investment casting manufacturer and supplier
      · 0 replies
    • ChineseSpare ChineseSpare

      ChineseSpare.com is an e-commerce platform which is integration of Chinese spares sales and engineering services. China spare parts, products Manufactured in China. Since its establishment, relying on the Middle East countries’ engineering projects, we have mainly exported a large number of mining spares and on-site technical services support, such as Saudi Arabia, the United Arab emirates and other countries. Meanwhile, in the aspect of mining machinery spare parts, we have rich experience in export and transportation. We also have a deep cooperation and keep in good relationship with many domestic large-scale machinery manufactures and foreign well-known factories, distributors and agencies.
      Considering about our customers’ purchasing needs, saving the delivery time, reducing management cost, we build and supply the E-commerce platform. Now we have nine types of products: General Mechanical Parts, Machined Parts, Mechanical Equipment & Assemblies, Electronic Driving, Electronic Components, Process Control & Instruments, Materials, Engineering Services and others. In order to provide more convenient, thoughtful, high-quality services for our customers, we set up the branches in China, Singapore and Middle East. Thanks for your inquiry.
      We abide by honesty as root scrupulously, customer highest, service foremost to satisfy with our customers. We take the business order ”First-class quality, First-rate reputation” and consistently insist on the principle-“customer first” to serve our customers.
      website:www.chinesespare.com
      · 0 replies
    • Engr. sazzad hossain  »  saurabhjain

      good job and all the best.
      · 0 replies
  • Posts

    • Hi mates, I need some help in a project. In short, I have a part of a mechanical assembly, and this part broke due to material failure. I need to propose a solution only by changing the material, not the desing (at least, the main focus have to be only change the metal...). This is an axle from a BMX jump bike, it failed on me suddenly. Actually, I didn't realize at the moment that it broke into 2 pieces. A friend of mine asked for the bike and I gave it to him, he jumped in and asked what's wrong with the front hub since it was like "loose"... The nuts were in place, all seemed fine but it really had a little gap. When we were loosening the nut, we realized that we had two separate pieces of the axle, lol. Here are some amplified images of the axles and the fractures from the two perspectives. I noticed that the failure started right in the last thread of the axle, meaning that it had stress concentration caused by the thread cavity. What information can you deduce when looking at the fracture? The axle is made of Chromoly (I think it's 4130 or 4140 Cr-Mo, correct me if I'm wrong). The diameter (almost uniform along the axle) is 3/8" of an inch (around 0.95 mm). The total lenght of the axle is around 16.25 mm = a little bit more than 5/8 inch. I will attach a diagram to show up what's the situation. The words are "gancho"=dropout, where the fork of the bike sits the axle. "Apoyo rodamiento" = where the bearing seats on the axle. The distance (c to c) of the two sites is 18.5 mm = almost 3/4 inch, so I assume that there's some bending involved due to the separation, and it's not only shear stress. There's also a lot of fatigue because of the abusive nature of BMX tricks (mostly street BMX tricks, when you ussually land tricks with your bike from more than 5 ft). Looking at the image where the 2 pieces are, we can see the threaded piece and at left there's the another one, the mirror-like polished site right there is where the bearing sits (it's a sealed catridge bearing). The fracture occured closer to the bearing seat, on the first thread like I said before (stress concentration?)...   Images at https://filebin.net/6j8yeglbvyylqgwg   Thank you in advance for any reply! Matt.-
    • Can an engineer, review and stamp plans prepares by someone else?
    • There is a vide range of bearing blocks readily available in the market,  if the required design doesn't falls in that, prepare detailed manufacturing drawings of all the parts and get it made from the supplier. After all any machine is an assembly of standard bought out parts, manufactured parts and hardware.Bill of materials to prepared first. 
    • Does anyone know what the principle of the work is a valnut cracking and shelling machine, how they work, does anyone have any drawings about it. For example, like the ones in the picture  
    • I'm facing this problem from a very long time. Let's say you founded a Patent/Design that fits perfectly for your needs. Now the problem is how can you realize that design? ( Design in Solidworks is ready but physically it's not ) How can you make from a block steel to the required machine? I know that has to happen using milling machine, lathe and other different types machines and processes but what's the exact procedure? How the marking has to be done? Any books or documentation about this? I know that this is vague but there should be something about this. Eg. Let's say a bearing block. How that has to be made ?
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