Category: Learning Center

THINK3D is proud to have worked with VOLTRAN, an EV charging startup in supplying components for the DC 60 KW chargers developed by VOLTRAN to be deployed across various locations in India.

VOLTRAN is an EV charging startup founded by the founders of THINK3D. Having mastered the various manufacturing processes over the last 8 years, THINK3D management team decided to launch its own product. That culminated in setting up a new company, VOLTRAN ELECTRIC LLC to set up EV fast charge hubs across highways in India. For these fast charge hubs, VOLTRAN has taken assistance of THINK3D to manufacture components for the DC fast chargers. THINK3D has done the sheet metal work for the chassis, bus bars and CNC machining of the various components. With the expertise gained, THINK3D is now confident to serve the booming EV market. 

About VOLTRAN: VOLTRAN is an EV charging startup founded by the founding team of THINK3D. VOLTRAN is into setting up DC Fast Charge hubs across highways in India. Each hub consists of 5 60KW DC fast chargers, a lounge facility, restroom and office space. Each hub is open 24/7, so customers can comfortably drive on the highways without having this range anxiety. The first hub is coming up at Suryapet on Hyderabad – Vijayawada highway. At VOLTRAN, we shall also install DC fast chargers for customers looking to set up DC fast chargers at their locations. Please visit www.voltran.in to learn more.  

About THINK3D: THINK3D was founded in the year 2014 with a mission to democratize 3D Printing in India. The company slowly expanded into CNC Machining, Injection Molding, Sheet Metal, Vacuum Casting to become a full fledged manufacturing company. In 2018, the company has set up a state-of-art manufacturing facility in Visakhapatnam with various industrial 3D Printers, CNC Machines, Injection Molding machines all at one place. Please visit www.think3d.in to learn more.

Design For Manufacturing (DFM) is the process of designing parts, components or products for ease of manufacturing with an ultimate goal of making a better product at a lower cost. This is done by simplifying, optimizing and refining the product design. In general, five principles are thoroughly examined during DFM. They are:

• • Process
  • Design
  • Material
  • Environment
  • Compliance / Testing

DFM should occur very early in the design process, right at the start of the product design process. As the design progresses through the product life cycle, it becomes very expensive to make changes and also very difficult to implement those changes. Early DFM allows design changes to be executed quickly at the least expensive location.

Also, a well executed DFM should include all stakeholders – engineers, designers, contract manufacturers, mold builders and material suppliers. The fundamental intent of this “cross-functional” DFM is to challenge the design at all levels – component, sub-system, system and holistic levels to ensure the design is optimized and does not have unnecessary cost embedded in it.

Pulling all the stakeholders together early in the design process is easier if a new product is being developed. But if we are dealing with an established product, challenging the original design is a necessary element of a thorough DFM process. Many a lot of times, mistakes in the original design are repeated by replicating a previous design. Always question every aspect of the design.

• Look at the original drawings
• Tear down the product
• Look at competitive and near-neighbor products
• Talk to vendors / contract manufacturers

DFM is the most important exercise any product designer should do before embarking on the product development. Unlike software development where bug can be resolved by pushing in a new line of code, in case of hardware, it isn’t possible. Costly recall of hardware products is required if there is any faulty part in the product.

Let us take a closer look at the above mentioned 5 different factors

PROCESS
Manufacturing process is the first aspect to be looked into when designing a product. Manufacturing process chosen must be the most optimal one for the product. Different manufacturing processes have different MOQ requirements for the product to become price competitive. One has to thus choose the process carefully. You wouldn’t want to use highly capitalized process like injection molding which involves building of tools and dies to make a low-volume part that could have been manufactured using a lower-capitalized method, such as thermoforming. When determining the manufacturing process, one should take into consideration the following – quantity of parts being made, the material being used, complexity of the surfaces, the tolerances required and whether there were secondary processes required.

DESIGN
Good design is essential for a good product. The actual drawing of the part or product has to conform to good manufacturing principles for the manufacturing process you’ve chosen. In case of plastic injection molding, the following principles would apply:

• Constant wall thickness. This allows for consistent and quick part cooling
• Appropriate draft (1 – 2 degree)
• Texture – need 1 degree for every 0.001” of texture depth on texture side walls
• Ribs = 60 percent of nominal wall
• Simple transitions from thick to thin features
• Wall thickness not too small
• No undercuts or features that require side action – all features “in line of pull/mold opening”
• Spec the loosest tolerances that allow a good product

Always be sure to discuss the design with your contract manufacturer who can ensure that your design conforms to good manufacturing principles for the selected process.

MATERIAL
It is also very important to select the correct material for the product. Below are some material properties to consider during DFM

• Mechanical properties – How strong should the material be?
• Optical properties – Should the material be reflective or transparent?
• Thermal properties – How heat resistant does it need to be?
• Color – What color does the part need to be?
• Electrical properties – Does the material need to act as a dielectric?
• Flammability – How flame/burn resistant does the material need to be?

Always make sure you discuss the  material with your contract manufacturer before deciding on the material to be used.

ENVIRONMENT
The product must be designed to withstand the environment it will be subjected to. Different materials have different properties like electrical conductivity, corrosion resistance and so on. Make sure the product is designed to function properly under its normal operating conditions.

COMPLIANCE / TESTING
All products must comply with safety and quality standards. Sometimes these are industry standards, others are third-party standards and some are internal, company-specific standards.

FEW ADDITIONAL FACTORS TO TAKE INTO CONSIDERATION
The goal of DFM is to reduce manufacturing costs without reducing performance. In addition to the principles of DFM, here are five factors that can affect design for manufacturing and design for assembly:

1. Minimize Part Count: Reducing the number of parts in a product is the quickest way to reduce cost because you are reducing the amount of material required, the amount of engineering, production, labor, all the way down to shipping costs.

2. Standardize Parts & Materials: Personalization and customization are expensive and time-consuming. Using quality standardized parts can shorten time to production as such parts are typically available and you can be more certain of their consistency. Material is based on the planned use of the product and it’s function. Consider:

• How should it feel? Hard? Soft?
• Does it need to withstand pressure?
• Will the part or product need to conduct heat, electricity?

3. Create Modular Assemblies: Using non-customized modules / modular assemblies in the design allows one to modify the product without losing its overall functionality. A simple example is a basic automobile that allows you to add in extras by putting in a modular upgrade.

4. Design For Efficient Joining: Can the parts interlock or clip together? Look for ways to join the parts without the use of screws, fasteners or adhesives. If you must use fasteners, here are a few tips

• Keep the number, size and variation of fasteners to a minimum
• Use standard fasteners as much as possible.
• Use self-tapping and chamfered screws for better placement.
• Stay away from screws that are too long or too short, separate washers, tapped holes, round heads and flatheads.

5. Minimize Reorientation Of Parts During Assembly & Machining: Parts should be designed so that a minimum of manual interaction is necessary during production and assembly.

6. Streamline Number Of Manufacturing Operations / Processes: The more complex the process of making the product, the more variables for error are introduced.

7. Define Acceptable Surface Finishes: Unless it must be trade show grade, go with function rather than flashy for your surface finish.

10 OUTCOMES OF AN EFFECTIVE DFM
Below are 10 generally accepted Design for Manufacturing principles that were developed to help designers decrease the cost of and complexity of manufacturing a product. The results of a successful DFM are quantifiable in a host of ways.

1. Minimize the number of product parts: Reducing the number of parts in the product is an easy way to lower the cost of product as it reduces the amount of material and assembly labor required. Reducing the number of parts also means less engineering, production, labor and shipping costs.
2. Use standardized parts wherever possible: Customization is not only expensive, it is also highly time consuming. Use standardized parts as much as possible. Standardized parts are made to meet the same quality metrics, every time and they are already tooled. So you save costs and you won’t have to wonder whether they’ll pass inspection.
3. Create a modular design: Using modules can simplify any future product redesign, and also allows for use of standard components and the re-use of modules in other projects.
4. Design multi-functional parts: Design parts with more than one function. It is a simple way to reduce the total number of parts.
5. Design multi-use products: Different products can share parts that have been designed for multi-use. Can your product use standardized parts that can be used in multiple products?
6. Design for ease of fabrication: Choose the ideal combination between the material and manufacturing process that shall minimize production costs. Generally designers opt for very tight tolerances which is an absolute no-go. Avoid expensive and labor intensive final operations as painting, polishing and finish machining.
7. Design product to join without using screws, fasteners, adhesives: Is it possible for your product to interlock or clip together without the need for any screws / rivets? Screws add only about 5% to the material cost but add 75% to the assembly labor. Wherever fasteners are required, try to keep the size, number and type to a minimum and use standard fasteners wherever possible.
8. Design part to minimize handling during production and assembly: Handling includes positioning, orienting and fastening the part into place. For orientation purposes, use symmetrical parts wherever possible.
9. Minimize assembly direction: If possible, your parts should assemble from one direction. Ideally, parts should be added from above, parallel to the gravitational direction. This way assembly is facilitated by gravity rather than fought by it.
10. Design part to maximize compliance: Rely on built-in design features like tapers or chamfers, or moderate radius sizes to guide insertion of equipment and to protect the part from damage.

About 70% of the manufacturing costs of the product are determined by the design decisions. So, it is really important to adhere to the best design practices possible.

Silicone is a relatively new material in 3D Printing. Due to high viscosity of the material, it took time to develop this material for 3D Printing. Silicone can be 3D Printed using SLA technology. Silicone is an elastomer and unlike thermoplastics, it can’t return to liquid state after being solidified.

Properties & Applications Of Silicone:
– Excellent thermal stability, up to 200°C and as low as -80°C
– Repels water and is resistant to steam
– Ideal compression set for forming tight seals
– UV resistant
– Electrical insulator, even under water
– Tear resistant
– Transparent, ideal for optics
– Can be sterilized
– Flame retardant
– Food safe
– Biocompatible

Those properties lend silicone to be found in a wide range of industries, such as manufacturing, energy, food production and handling, automotive, aerospace, consumer goods, healthcare, electronics and agriculture. Everything from gaskets and tubes to keypads and switches are made from silicone rubbers. The sound dampening devices in cars and the black boxes in airplanes are also made from the material.

Comparison with Liquid Silicone Rubber (LSR):
Using liquid silicone rubber (LSR) to manufacture molded parts has been around for long time. LSR provides a shore hardness of 30A to 70A. It gives a smooth texture, offers multiple colors and is primarily used in high volume prototyping pilot runs and end-use production parts.

Limitations of 3D Printing with Silicone:
Currently, the parts that can be 3D Printed are modest in size. Parts must be no larger than 4.7 in. by 2.8 in. by 3.9 in. (119.38mm x 71.12mm x 99.06mm). Color choice is either translucent white or black for 60A. So, if one is looking for color parts then molding is the best bet. That said, if your aim is simply to test design integrity, color might be irrelevant.

One other important consideration that is pertinent to all transitions from printing to molding is if you are planning to use 3D Printing as a prototyping step and move on to molding for on-demand manufacturing quantities, make sure your designs are moldable before putting special features into the parts.

Last, but not least, is cost. While printing in silicone is not inexpensive compared to other printing options and materials, it is less expensive than paying for a mold, and possible iterating with multiple molds. So, silicone isn’t cheap, but it is a good option for saving money during prototyping, and possibly throughout a part’s life cycle.

Oxygen is a very interesting gas that keeps humans and every other lifeform on Earth from becoming extinct. But that is only because our bodies have evolved to make use of oxygen in some spectacular ways. Otherwise oxygen is a highly toxic and corrosive element more suitable for sending rockets to space than for sustaining life.

Many metals like iron and its offspring carbon steel quickly rust if not protected with paint, plating and similar coatings. But there are other metals like aluminum, stainless steel that react with oxygen in the air to form a thin protective shell known as passivation layer. This passivation layer protects the metals from getting rusted.

The good news is that a broad selection of corrosion-resistant metals is available, and we machine, 3D print, and fabricate the most often used ones. Here’s a quick overview of each, along with a few application examples:

Aluminum:
Aluminum is an excellent choice for various applications. It’s many alloys are strong, light-weight, non-magnetic, electrically conductive, making them suitable for everything from cooking utensils to machinery hardware, electronic housings and scientific instruments. Pure aluminum parts when exposed to air form a thin aluminum oxide layer which then resists corrosion and rust. If artificial passivation / hardening is required, there are multiple options to go for like anodization.

Titanium:
Titanium is a light weight metal but highly expensive one. It is as strong as steel but at half the weight and is twice the strength of aluminum with one and half times the weight. Titanium is also one of the most corrosion resistant metals due to the generation of titanium oxide coating when oxygen is present. Ti-6Al-4V titanium is a “workhorse alloy” for its widespread use in medical implants, aircraft engines, power generations facilities, sporting equipment and other applications.

Stainless Steel: 
Stainless Steel is another versatile material for CNC Machining. There are various alloys of stainless steel being used in the CNC machining for the diverse properties this material exhibits. Stainless Steel gets its protective layer from chromium oxide. That is because the element that gives all stainless steels their name is chromium. For instance, 303 stainless steel contains between 17 – 19% chromium, 9% nickel and a smattering of trace elements like manganese and phosphorous. There is also a tiny amount of sulfur which makes 303 one of the most machinable stainless steels but slightly less corrosion resistant.

Next is 304, another “general purpose” grade stainless steel followed by 316 stainless steel, a tougher, more heat, wear and corrosion-resistant grade thanks to 2% molybdenum. Each of these materials are also available in low carbon grades (as in 304L & 316L) that are bit softer and slightly more weldable than their counterparts.

Finally comes another aerospace favorite, 17-4 PH. Unlike 300 series stainless steels, 17-4 can be made quiet hard through heat treatment so this is often found in gas turbines, petrochemical applications and aircraft parts.

Cobalt Chrome:
This alloy has many of the same mechanical attributes as stainless steel but is slightly stronger and more wear resistant. Cobalt Chrome is a bio-compatible material. We can see this material in dentures, knee joint replacement although the material is widely used in many industrial applications such as furnace liners and engine components. Cobalt Chrome is currently limited for DMLS 3D Printing.

Inconel: 
Inconel is another unique DMLS offering. That is because this material is quite challenging to machine but can be readily 3D Printed into large parts as large as 400mm x 800mm x 500mm. Like 17-4 stainless steel, Inconel 718 is precipitation-hardenable but this material also contains far higher amounts of nickel along with 5% or so of the refractory metal niobium and nearly that much molybdenum. This explains the great strength and high heat capabilities of Inconel making it a preferred material for any component subject to temperatures up to 1,300°F (700°C) and extreme mechanical loading.

Brass:
Brass is a copper and zinc alloy that is easily machinable and sits at the opposite end of the machinability chart from Inconel, Titanium & Cobalt Chrome. Brass material is useful for plumbing fixtures and adapters, bearings, heat sinks, threaded fasteners and any other parts requiring high electrical and thermal conductivity. There are 2 kinds of brass materials available in the market. One is free-cutting brass C360 which gets its name from a trace amount of lead that eases machining and makes this yellow metal quite popular for high volume screw machine work. Similarly, alloy C260 is known as cartridge brass for its excellent formability and subsequent use in bullet cases and in other “deep drawn” commodity components. For turned and milled parts, brass is an attractive alternative with many admirable qualities, not the least of which is its good looks.

Copper: 
Copper comes in 2 grades – C101 & C110. Each grade has distinct mechanical properties and all are considered planet’s most electrically conductive materials. Copper overlaps with brass in terms of various applications but is generally more formable, less machinable, and a fair bit more expensive. It’s a great choice for high-performance heat exchangers and electronic or electrical applications (EMI shielding, for instance). Thanks to its anti-microbial properties, copper is enjoying increased use in hospital equipment.

At THINK3D, we offer CNC machining of all the above mentioned materials. With more than 10 CNC machines in-house, we have one of the best CNC machining & post processing facility to cater to all your machining needs.

Tolerance is one very important element in manufacturing. It is virtually impossible to design a product to the exact 3D design as manufacturing involves physical processes and thus it is next to impossible to create that perfect product. The variation between the dimension as per CAD diagram and the acceptable dimension in the physical product is what is called tolerance. Different manufacturing technologies can achieve different kinds of tolerances depending on the kind of machine being used, machine accuracy and material being used. Let us first look at 3 major manufacturing technologies available in the market currently – 3D Printing, CNC Machining & Sheet Metal Fabrication.

CNC Machining: CNC Machining provides highest tolerance of all technologies because of the way machines are operated. In CNC Machining process, material is cut from the block to get the required shape. In CNC Machining, a gantry is present that moves to the exact location and chips away the material. Since the machine movement is gantry based, the material shall be removed to the exact tolerance.

3D Printing: In 3D Printing, parts are manufactured through deposition of material. In 3D Printing, laser / infrared light / heated nozzle are used to add material layer by layer and create the final part. As 3D Printing is additive in nature where material is melted and fused, the tolerances achieved in 3D Printing aren’t as high as those achieved in CNC Machining. SLA technology offers the best resolution of all technologies. FDM offers the lowest resolution. Typical tolerance varies from 10 micron to 100 micron.

Sheet Metal: Sheet  Metal provides the lowest tolerance of all because of the very nature of part production in sheet metal fabrication. Sheet Metal Fabrication involves bending the metal parts to achieve the desired shape. When bending the metal parts, the expansion / contraction of the part depends on the metal and tool in use and their respective tolerances. The part behavior varies depending on where the part is bent. If the part is bent closer to the edge, it expands at a different rate than when the part is bent far from the edge. In sheet metal fabrication, the tolerance on the surface is lot higher than the tolerance on the bent part.

To summarize the discussion, CNC Machining provides the best tolerance of these 3 technologies, then comes 3D Printing and finally sheet metal fabrication.