3D PRINTING INTERVIEW QUESTIONS


Most Important Frequently Asked 3d Printing Interview Questions



    1. Question 1. What Is 3d Printing?

      Answer :

      3D printing is the automated process of building a three-dimensional object by adding material rather than taking material away (as in drilling or machining). The process, also known as additive manufacturing, was first introduced in the late 1980s. It was first commercially used as a rapid prototyping method in the aerospace and automotive industries. Charles Hull, who later co-founded 3D Systems, had a patent issued for a stereo lithography system (or SLA for short).

      In 1988, 3D Systems sold its first industrial 3D printer utilizing the SLA technology.

      In the early 1990s, many industrial 3D printing companies were founded; they all came up with newly invented processes. Only three of the major 3D printing companies from that time when 3D printing’s only application was industrial, are still on the market. The most important ones are 3D Systems, EOS, and Stratasys.

      It wasn’t until 2009 that 3D printing became commercially available to the masses. The RepRap open source project opened the door to affordable desktop 3D printers utilizing the Fused Deposition Modeling (FDM) technology. Then, and in the years following 2009, new and other companies started innovating, creating and improving the consumer/desktop 3D printer to the point where today, we have high-quality, affordable and also expensive desktop 3D printers utilizing the FDM technology (and others).

    2. Question 2. How Does 3d Printing Work?

      Answer :

      To create a 3D printed object, you use an “additive process”. The three-dimensional object is created by laying down successive layers of material until the object is finished.

    3. Question 3. What Are The Limitations Of 3d Printing?

      Answer :

      Although it is already deeply implemented in the world of prototyping, 3D printing is still some years away from having a breakthrough in the world of manufacturing. This breakthrough would allow 3D printing to spread from just prototyping, with the exception of select components already being manufactured by 3D printers, to being widely implemented in everyday manufacturing processes all over the world.

      The main aspect keeping this from happening sooner is the relatively long time it takes to 3D print something that can just as well be manufactured using traditional methods (and we all know that time means money).

      3D printing is also limited by the size of the 3D printer. Although there are some pretty big units 3D printing with cement, for example, high-quality and precision parts are limited to smaller machines which can also be very expensive depending on what they are designed to be capable of.

    4. Question 4. Is There A Difference Between 3d Printing And Additive Manufacturing?

      Answer :

      The short answer is no. The term “3D printing” comes from the use of inkjet printer heads (in the first 3D printers) to deposit, either layers of UV-curable photopolymer resin or a binding material onto a layer of powder in a powder bed process. However, the term now universally encompasses all additive manufacturing technologies.

      The more technical, or correct, way of referring to the automated process of building a 3D object from scratch using a digital file is “additive manufacturing”.

    5. Question 5. What Is The Difference Between 3d Printing And 4d Printing?

      Answer :

      4D printing is a subset of 3D printing. In “normal” 3D printing, the end product is static, unless some flexible material is used, and it is meant to stay in that form. 4D printing is a way of “programming” the material/object to change form or functionality when given the correct impulse.

      For example: running shoes could be designed to change the way they feel or fit depending on the activity of the wearer. Also, clothing could change its functionality depending on the weather. Although these products and solutions are not yet on the market, various research institutions like the MIT Self-Assembly lab are working on improving such technologies.

    6. Question 6. Are 3d Printed Goods As Good As Those Manufactured “traditionally”?

      Answer :

      3D printing has enabled certain products to be improved beyond the capabilities of traditional manufacturing processes like jet engine components.

      But on a general level, it would be a subjective statement to suggest that a certain 3D printed product is better or worse than its traditional counterpart. Seen on an economic level, 3D printing is on its way to becoming a very efficient, resourceful, and cost effective means of production and will probably surpass conventional manufacturing processes in those aspects in the future.

    7. Question 7. Who Invented 3d Printing?

      Answer :

      Charles (Chuck) Hull, co-founder of 3D Systems, invented the solid imaging process known today as stereolithography (SLA). This was the first commercial 3D printing method. He first thought of the idea in 1983 while using UV light to harden tabletop coatings. In 1986 he received the patent for the process.

      By the way, Charles Hull is also the person who invented the .STL file format, which is the most common 3D printing file format.

    8. Question 8. Can I Use 3d Printing In Education?

      Answer :

      • Yes, 3D printing is already being introduced to students at an early age.
      • 3D printing enables the physical manifestation of someone’s thoughts and ideas. The hands-on experience makes a technical subject fun and attractive, even for people who aren’t especially interested (yet) in design, architecture, computer science or engineering and many other fields of study. For some, what used to be a dry and theoretical and (as a result of that) boring class, can now become an engaging and hands-on experience.
      • China, for example, has plans to have every one of its elementary schools equipped with 3D printers by 2017. The early immersion of students to the new technology will make them fit for the future, when 3D printing will become more and more important for the workplace and everyday life.
      • Also, in Japan, Kabaku and Microsoft have developed a 3D printing and programming learning tool. Based on the popular video game Mine craft, students can design structures in the game and have their creations output on a 3D printer. This helps the students realize the potential impact that their imagination and ideas can have. And makes them realize that designing is a process of trial and error, often involving several iterations before getting it right.
      • There is no debating whether or not 3D printing can be used in the classroom. It’s more a question of when. For further reading, check out this article on how 3D printing improves education. Also, there is an interesting Teacher‘s Guide to 3D Printing here.

    9. Question 9. Will 3d Printing Be Bigger Than The Internet?

      Answer :

      As 3D printing has only begun to see global acceptance and implementation in recent years, it is too soon to know for certain whether 3D printing will be a life-changer comparable to the internet. After all, when computers were first invented, no one knew the tremendous impact they would have. The same goes for the internet. Growing numbers in the 3D printing industry suggest that the technology is going to be huge, but only time will tell- if the impact going to be “internet-size”.

    10. Question 10. What Types Of 3d Printing Filaments Are There?

      Answer :

      There are many different kinds of 3D printing filaments. First of all, they come in two conventional diameters: 1.75mm and 3.00mm.

      The most common materials used in FDM 3D printing are PLA and ABS. They are popular for their ease of use (ABS being a little more complicated to 3D print), and their affordability.

      But as far as what materials you can print with are concerned, there are almost no limits. It is possible to print in pure metal, food and all sorts of thermoplastics whereby metal and food don’t come in filament form for obvious reasons. But don’t be confused, if you see a spool of filament that says metal on it. In this case, metal dust is mixed with thermoplastic material for use in desktop FDM 3D printers.

    11. Question 11. How Do I Find Out What Kinds Of Filament My 3d Printer Supports?

      Answer :

      • You have a few options. The obvious ones are to visit the manufacturer’s website or read the 3D printer manual. The supported filament type should be stated clearly.
      • Another way is to ask Google. You should be able to find all sorts of people writing about their experiences using different filament types with their 3D printer, even types not explicitly listed by the manufacturer that still work. But keep in mind that the warranty won’t be valid any longer if your 3D printer breaks because of a filament the manufacturer does not support.
      • Also, some manufacturers lock the users into using the manufacturer-made filaments, which usually comes in a proprietary filament cartridge. This way, your choice of (cheap) filaments is limited; on the other hand, you get the best printing results possible (the manufacturers claim).

    12. Question 12. Will Unsupported Filaments Ruin My 3d Printer?

      Answer :

      You are well-advised to operate your 3D printer within the guidelines given by the manufacturer. Often, the use of the wrong filament can result in damage done to the hot end of your 3D printer. Generally, make sure not to heat the nozzle to temperatures above the given guidelines and only use filaments listed by the manufacturer.

      For example, carbon fiber infused filament will erode the nozzle, if the nozzle is not made of material suited for carbon fiber. (But as 3D printers are modular, you can of course replace a worn-out nozzle.)

    13. Question 13. What Software Do I Need For 3d Printing?

      Answer :

      To prepare an existing 3D model for 3D printing, you will at least need a 3D slicer. Most 3D printers come with their own slicing software. The most popular open source 3D slicer is Cura, the most versatile Simplify3D.

      If you are also interested in designing 3D models yourself or in modifying existing models, you will need 3D modeling software.

    14. Question 14. How Do I Create 3d Printable Models?

      Answer :

      First, 3D models can be made using 3D modeling software or real life objects which are then scanned and turned into 3D model files with specialized software often provided by the manufacturer of the scanning device. After that, the 3D models need to be passed through a 3D slicing program to become a 3D printable model.

    15. Question 15. What Is A 3d Printing Model?

      Answer :

      A 3D printing model is a file that a 3D printer can read and interpret. It is used to tell the 3D printer where to put the nozzle in order to create the physical object. The model file contains geometrical information that will have to be interpreted by a slicing software that turns the geometrical input into commands the printer can process.

    16. Question 16. What Are The Most Common 3d Printing File Formats?

      Answer :

      There are quite a few 3D printing file formats. Here are the most common ones.

      • STL: This is the most popular 3D model format, all slicing tools support it. Here is a more detailed overview of the STL format and how it works.
      • OBJ: Also important – and also supported by all major slicing tools – is the OBJ file format. In contrast to STL, OBJ is able to store color and texture profiles; we guess it will become more popular when multicolor printing takes off.
      • PLY: PLY, the Polygon file format, was originally used for storing 3D scanned objects.
      • 3MF: 3MF is a new file format developed by Microsoft, Autodesk, HP and Shape ways. It is not clear if this will be widely adopted – we’ll have to wait and see.

    17. Question 17. How To Start If I Want To Design A 3d Print Model?

      Answer :

      You are going to want to download and install a 3D modeling software. You don’t have to go and buy the most expensive one on the market. In fact, you don’t need to buy one at all. There are lots of good, free 3D modeling programs out there that are perfect for beginners. Start with simple models, like a cube, then work your way through more complicated objects.

      Here are step-by-step tutorials for learning 3D modeling using

      • FreeCAD
      • 3D Slash
      • TinkerCAD
      • More tutorials

    18. Question 18. How Can I Modify An Existing 3d Printing Model?

      Answer :

      You can modify existing 3D models by importing the file into a 3D modeling program. From there you can make all the changes you want. When you are done making changes, remember to save your progress and export the 3D model if you want to.

      There are also special tools for editing STL files that are not full-blown CAD programs – and therefore are easier to use.

    19. Question 19. Where Do I Get Free 3d Printable Models?

      Answer :

      Thingiverse is a large and popular 3D file sharing platform. By number of available designs, it is the largest 3D file sharing platform. Anyone can join to upload 3D models and anyone can browse and download files for free.

    20. Question 20. What Is The Minimal Wall Thickness Of A 3d Printing Model?

      Answer :

      • When deciding on the wall thickness of your print, there are a few important things to keep in mind.
      • First of all, if you have an extremely detailed model of a building, for example, scaling the model down for 3D printing will scale every aspect of the model down including minuscule details and wall thicknesses. There comes a point where the 3D printer is no longer capable of printing such fine details. That can result in super fragile prints and missing details. Therefore, while preparing a file for printing it is important to know which parameters to alter in order to ensure a good result.
      • The next aspect to consider is the material and technology you are using. Certain materials will remain stable at thinner wall thicknesses than others. User guidelines should be provided by the filament manufacturer.
      • Using FDM technology, the minimum wall thickness typically lies between 0.05mm and 0.1mm – depending on the resolution your 3D printer supports. However, this doesn’t mean that walls printed at that thickness will be stable at all.
      • The shape of your 3D model is also a critical aspect. For example, if your 3D model has a part with a lot of overhang, the structures supporting that overhang will need to be thick enough not to warp or break. Also, you need to make sure that supporting walls are strong (thick) enough to hold the weight above it. Generally, 1mm is the lower limit for wall thickness and 2mm is recommended.

    21. Question 21. Why Has A 3d Printing Model To Be Watertight?

      Answer :

      “Water tightness” in a 3D printing model refers to the mesh of the 3D model. The mesh itself must not have any holes. Otherwise, the 3D printer may not be able to print the model. This kind of problem can be fixed using a 3D model repair tool.

    22. Question 22. Are 3d Printing Models Copyrighted?

      Answer :

      Yes, some 3D designs are copyrighted. The UK government has just extended the copyright for industrially manufactured artistic works to the life of the designer plus 70 years (it used to be 25 years before). This prohibits individuals from freely copying a design and 3D printing it with their own tools and resources.

    23. Question 23. Can I Use A 2d Photo To Get A 3d Printing Model?

      Answer :

      • Yes, but results will vary. Also, it really depends on the scanning method you’re choosing. Many 3D scanning devices use a series of 2D photos to build or create an actual 3D model of the object being scanned.
      • Also, most of the 3D printed figurines are made from a multitude of 2D photos, which are stitched together.
      • “Scandi” is an app where the user can take 360° panorama pictures. The pictures can then be 3D printed in color in the form of a sphere. This allows for a more immersive viewing experience of the photo. The app also allows the user to take 3D photos for creating 3D models of people, animals or objects. And if you want to have your model 3D printed, Scandi prints and ships the 3D print to your home.

    24. Question 24. Who Can Design A 3d Printing Model For Me?

      Answer :

      If you do not know anyone who knows how to handle a 3D modeling software (CAD software), e.g. architects or 3D designers: Look up your local 3D printing service bureau and have them design a specific object for you.

    25. Question 25. How Can I Protect My 3d Printing Design From Being Stolen?

      Answer :

      • You can place your 3D printing designs under copyright protection law, but that doesn't keep them from being stolen, once the design makes it online. If your design has been stolen for profit or the copyright is otherwise being infringed, your only course of action is to issue a DMCA takedown notice or to take legal action.
      • Many startups are working on implementing copyright management into 3D printable object. But there is no gold standard yet.
      • You can also place your 3D design under a Creative Commons, non-attributable license, which allows other people to copy, distribute, remix, transform and build upon the design. However, the user must give appropriate credit, provide a link to the license and indicate if changes were made. This license does not permit commercial use of the material placed under the license.

    26. Question 26. How Can I Reduce My 3d Printing Costs?

      Answer :

      There are several ways to reduce your 3D printing costs. Variables such as material, size, and infill of your print can make a huge difference in price over time, if they are optimized.

      What also makes a difference is deciding whether or not you want buy your own 3D printer or use a 3D printing service. For one-time prints it will be cheaper to use a service. But if you want to do a lot of 3D printing, it might pay off soon to buy your own 3D printer and materials.

    27. Question 27. How To 3d Print Text Or Nameplates?

      Answer :

      This sounds pretty standard but could be quite difficult if you have no experience using 3D modeling software. Many 3D modeling platforms have a function to use text, even in different fonts. It is important to note that with 3D printing, you need a suitable base. This will keep the letters in place and from falling over.

      Here are some tutorials covering the basics in different 3D modeling software’s:

      • How to 3D Print Letters or Text using FreeCAD
      • How To 3D Print Text Using SketchUp
      • Blender Tutorial for 3D Printing: How To 3D Print Text
      • 3D Slash Gets Text and Logo Modes
      • 3D Printed Business Cards: How to Make Your Own Portrait Card.

    28. Question 28. Which Materials Can Be 3d Printed?

      Answer :

      Printing is possible with a lot of materials. Most commonly known, desktop 3D printers can print with any number of thermoplastic and thermoplastics mixed with other materials like wood fibers, metal powder, glow in the dark compounds and much more. But beyond that, scientists are even experimenting printing with biomaterials in an effort to eventually be capable of 3D printing human organs for transplants.

      More on 3D printing materials:

      • 28 Great 3D Printer Filament Types (A Guide)
      • PLA Filament Guide: 32 Unique Types to 3D Print.

    29. Question 29. Which Materials Can’t Be 3d Printed?

      Answer :

      It’s hard to think of a material that can’t be 3D printed. Theoretically, given the right circumstances, nearly any material can be 3D printed. But practically speaking, liquids for example can’t be 3D printed, unless the room you are 3D printing in is at least below 0°C and you’ve equipped your 3D printer with the necessary modifications to do so. Other materials like naturally gaseous materials also can’t be 3D printed under normal conditions.

    30. Question 30. What Resolution Can A 3d Printer Print?

      Answer :

      The Resolution of a 3D printer is divided into two parts. First, there is the XY resolution which is the smallest movement the nozzle can make on the X and Y axes. Secondly, there is the vertical resolution which is the minimum layer thickness the 3D printer can be set to. That is the case for FDM 3D printers.

      Maximum resolution (quality) varies deeply depending on the 3D printing method being used.

    31. Question 31. What Is The Best Way To 3d Print Fully Functional Parts?

      Answer :

      The best way to have fully functional parts printed in good quality is to use a professional 3D printing service. To ensure the service can actually produce your design, it would be a good idea to contact the company’s customer support.

      Here is a list of professional and community-based 3D printing services.

    32. Question 32. What Are The Benefits Of 3d Printing Compared To Injection Molding?

      Answer :

      One major benefit of 3D printing compared to injection molding is the cost advantage. Injection molding requires a mold to be manufactured or formed first, which is a costly and delicate process. However, since injection molding costs decrease with increasing production volumes, there usually comes a point where injection molding makes more sense.

      Also, some geometric shapes that are 3D printable simply can’t be manufactured using injection molding.

    33. Question 33. What Are The Differences Between 3d Printing And Cnc Milling?

      Answer :

      The major difference between 3D printing and CNC milling is the starting point: With 3D printing, the manufacturing process starts from nothing, objects are built by adding material layer by layer. In CNC milling, the process starts with a block of material and is finished by removing material until the desired shape has been formed.

      Here is an article explaining the differences between 3D printing and CNC milling.

    34. Question 34. Is 3d Printed Gold As Valuable As “normal” Gold?

      Answer :

      First of all, gold is not a 3D printable material. Still, 3D printing is used more and more to make gold objects by 3D printing a wax model, which is then cast in solid gold. In other words, your gold, 3D printed or not, will be as valuable as the current market price for gold. In some cases, handmade jewelry by certain famous jewelers will sell for much more than their weight in gold.

    35. Question 35. What Is Not Suitable For 3d Printing?

      Answer :

      • When it comes to 3D printing, a lot is possible – but even more still isn’t possible. Using an FDM 3D printer, you cannot achieve an industrial-grade polished surface. This has to be post-processed.
      • Using an FDM 3D printer, you cannot achieve an industrial-grade polished surface. This has to be post-processed.
      • Now on a hypothetical level, it is not yet possible to 3D print a functional, complex electro-mechanical machine or product (like a car) in one go, even though individual parts can be 3D printed no problem. But researchers are already working on “production 3D printers“.
      • Also, bioprinting is not advanced enough yet to 3D print fully functional customized human organs on more than an experimental basis. That technology may still be some years off.

    36. Question 36. Is 3d Printing Food Possible?

      Answer :

      Yes. It 3D printing food is possible and is already being done. All you need to do is make the food inextricable. The food paste is then loaded into a syringe-like container anded through a nozzle onto a plate or build platform.

      There are some drawbacks, though. Even if you can create great looking food, it’s nearly impossible to 3D print a whole meal for several people – the printers are simply not fast enough. Still, chefs are embracing the 3D printing technology very fast.

    37. Question 37. Can Chocolate Be 3d Printed?

      Answer :

      Yes, chocolate can be 3D printed. Perhaps even better than other foods. Since chocolate can melt, it can beed through a heated extruder and cooled to a solid much like thermoplastics. Unfortunately, there’s no chocolate 3D printer available on the market – but you can resort to all-in-one printers like the Zmorph.

    38. Question 38. What Are The Most Advanced Things You Can Do With 3d Printing?

      Answer :

      • 3D printing has opened up new opportunities, particularly in the fields of aerospace and medicine. Certain jet engine components with complex inner geometry can now be manufactured using 3D printing. These parts would have been near impossible to manufacture using conventional methods.
      • Many space exploration projects/concepts rely heavily on the use of 3D printing. For example, the Russian and European space agency’s plan on 3D printing bases on the moon using moon soil instead sending all the materials from earth. This would save tons of money.
      • On the medical front, scientists are working on bioprinting, which would allow living tissues, bones and organs to be 3D printed/grown in a lab for transplant patients. Other advancements in medicine due to 3D printing are the design and creation of patient specific tools and objects.

    39. Question 39. What Is The Biggest Thing Which Was 3d Printed?

      Answer :

      The current Guinness World Record holder of the title “Largest 3-D printed object” is the Oak Ridge National Laboratory (ORNL). They have 3D printed a tool that will be used in the production of the Boeing 777X, a new and improved version of the popular and successful Boeing 777 airplane. The object is 17.5 feet long, 5.5 feet wide and 1.5 feet tall. According to the definition of the record title the object is solid.

    40. Question 40. Which Are The Fields Of Industrial 3d Printing?

      Answer :

      3D printing is being used in the aerospace, automobile, medical, architecture, consumer goods/electronics, defense, and education industry.

      Since there are many situations in which 3D printing is cost efficient, 3D printing has found its place in many industries. Think of the time saved by 3D printing an architectural model as opposed to constructing or milling one.

    41. Question 41. Which 3d Printing Companies Are Trustworthy?

      Answer :

      3D printing companies are no different than other companies when it comes to trustworthiness. The same precautions should be taken when looking into using a 3D printing company’s services as with any other company. To be safe, use Google to do some research on the company and look for customer experiences and reviews.

      These 3D printing companies are beyond doubt: 34 best 3D Printing Services of 2017.

    42. Question 42. How Big Is The 3d Printing Industry?

      Answer :

      According to statista, the 3D printing market is worth 7 billion USD in 2016 and is estimated to reach 21 billion USD by 2020.

    43. Question 43. Will 3d Printing Change The World?

      Answer :

      Many believe that 3D printing will indeed have a major impact on the world of manufacturing. Decentralized and local manufacturing combined with mass customization will certainly change the products are designed and manufactured along with the logistics of the processes. More on how 3D printing could change the world.

    44. Question 44. Where Can I Find A 3d Printing Store?

      Answer :

      3D printing stores are located in large cities like New York, Amsterdam, and Berlin. They sell 3D printed goods and some even offer 3D printing services with industrial-grade 3D printers.

      The first 3D printing store is located in Amsterdam and is called “Printed in Space”. The owner of the shop started out selling 3D printed objects from a Ultimate printer.

    45. Question 45. How Can I Get Something 3d Printed In Full Color?

      Answer :

      You can have objects 3D printed in full color at a variety of 3D printing services, the most popular being Shapeways, i.Materialise and Sculpteo. The largest industrial full-color 3D printing service in the world is white clouds.

      There are 3D printers on the market that do full-color 3D printing but they are still very expensive. Other processes like computational hydrographic printing use a special coloring technique which is a cost-effective, post printing alternative to other methods.

      More on hydrographic coloring: Hydrographic Printing: Affordable Full-Color Prints for Everyone.

    46. Question 46. What Is A 3d Printing Service Bureau?

      Answer :

      A 3D printing service bureau is a local business or outlet that will handle anything 3D printing for you. If you want something designed, you can ask your local 3D printing service bureau. If you want that design 3D printed as well, you can have your 3D printing service bureau do that for you. They will often also offer a 3D scanning service. Using a 3D printing service bureau can be very cost effective for your needs. It depends on how often you would like to do 3D printing.

    47. Question 47. Who Can 3d Print Parts For Medicine?

      Answer :

      Any company or organization may 3D print medical devices. However, any medical devices either manufactured in the USA or imported from outside the USA must be approved by the FDA (U.S. Food and Drug Administration).

    48. Question 48. How Can I Find A 3d Printing Service For My Business Problem?

      Answer :

      Giants like Stratasys, EOS and 3D Systems both offer professional and industrial 3D printing solutions for businesses.

    49. Question 49. Where Can I Buy Things Made With 3d Printing?

      Answer :

      3D printed things can be purchased almost in a lot of places. First of all, many major cities have 3D printing stores where you can buy 3D printed objects and even 3D printers. Perhaps the most popular place to buy 3D printed things is through an online service. These services let you upload an STL file and have it printed and delivered. Many other similar services exist.

      Also, ALL3DP offers a 3D printing price comparison service that makes uploading your file and selecting the material and printing service a snap.

    50. Question 50. How Can I Make Money With 3d Printing?

      Answer :

      There are many ways to make money with 3D printing. If you have a 3D printer, why not make money 3D printing things for other people while you’re not printing for yourself. Services like 3D Hubs are there for that exact purpose.

      Another way to make money is to design 3D models for money. Use your creative and modeling skills to make money with it. Online services like Shape ways allow you to sell your designs. The service 3D prints the model when someone orders it and you, the designer, get a portion of the price of the object. There are a number of comparable services.

    51. Question 51. What Is The Best Way To Sell 3d Printed Things Via The Internet?

      Answer :

      The best way to sell 3D printed things on the internet is a place where people look to buy 3D printed items. Popular platforms include Etsy (jewelry and art), Shapeways, i.Materialise and Sculpteo. 3D designers use these platforms to sell their 3D printed creations.

      The advantage of Etsy is that the designer is responsible for having the product made. This way, the entire end product can be shipped with all its accessories. Shape ways, on the other hand, ships the raw 3D printed object directly to the buyer without accessories.



Topic: 3d Printing Interview Questions
Posted by

No comments:

Post a Comment

Subscribe to: Post Comments (Atom)