User:Xiaomo Zhang

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Blog #1

Part A: Also part of your first blog assignment: Go to and find 5 things which have *.stl files associated with them for printing (some things are not 3D printable, but just shared designs). You should find five designs which you consider to be particularly: 1. useful 2. Artistic/beautiful 3. Pointless/useless 4. Funny/weird 5. Scary/strange. Comment on why you have chosen these things.

Part B: Read this article: Watch this video: Charlie Rose interviews a successful Designer


Do you feel that you are a tinkerer? Do you know anyone else who is? What do you think about the argument regarding the influence of corporate culture on tinkering? At the end of the article is the line, "...preserving the habitat of the tinkerer is one of the few time-proven ways we as a nation can get back on track." What do you think about this idea? What are the primary design principles you took away from the interview? What did you think when you saw his final project with his daughter? Can you think of how some of his principles might apply to our work?


3D glasses clip

3D movies are becoming more and more popular now in theaters. The avatar is one my favorite movies. In addition, 3D technology is flowing into TV market. The most advanced smart TVs are able to support 3D technology, which mean people could enjoy 3D channels for movies, live sports, and news. So I think that printing a 3D glasses clip by 3D printer creates much convenience for people’s daily life.

2.artistic and beautiful

Eiffel Tower

The Eiffel Tower design is very artistic and beautiful. It will be a great collection for people who are interested in architectures. The good point is that you could give the tower the color whatever you want: blue, yellow, red. And it could also be a good toy for children.

3.pointless and useless

Math cookie cutter set

I doubt that is it healthy to cook cookie with plastic in ovens. If it is sure that the materials that used to make the cutters do not contain any poisonous components, then it will be safe to work.

4.funny and weird


This is a megaphone model designed particular for iPhones products. The designer also posts a video to show that how big the voice difference is. which is awesome.

5.scary and strange

Wolverine Claws in plastic

Is it a toy for kids or adults? I think it is so dangerous to play with it for either kids or adults. If necessary, I prefer to use hard papers to make the claws, otherwise you had better put on safety glasses to you safe. Then what is the point of designing this?


I believe that becoming a tinkerer is definitely one the lofty dreams that every engineer has. For me, I am not a tinkerer. But I always wished to make myself a remarkable tinkerer. Since I was young, I had had great passion on any engineering related topics. Reading magazines and disassembling my "Transformers" usually took me a whole day and I never felt bored about them. However, as growing up from elementary school to college I had less time on my real interest gradually. At most of the time I had to figure out the solutions to the homework from math and physics classes. After came to Penn State, I tried my best to take myself back to what favorites me. I spent hours in laboratory to practice hands-on experience. And I believe it is definitely one of the smartest decisions I made in college life. I do have some friends who had experience of tinkering. But they never went deeper at the topic than what they learned from YouTube video. So I don't think I know anyone who is a so-called tinkerer. For the argument, first of all, I can tell the author had never been a boss of any corporation since he didn't look at the argument from the perspective of a corporation own. So these arguments about regarding the influence of corporate culture on tinkering is not fair the great corporations that the author mentions in the article. Secondly, I don't agree with what the author writes "where do we draw the line between tinkerers and hackers". It has no meaning to argue the “line”. I think he is exaggerating the potential damage from the group of tinkerers. He is put way too much responsibility on tinkerers on threatens to some great corporations. I partially agree with this point. Either giving compliment or belittling tinkerers is a wise mean to help the nation to move on. I suggest that leave the relationship between corporations and tinkerers alone. Trying to balance the relationship is only making it worse and worse. And getting the nation back to the track is critical. However, many other approaches are more practical than the one he mentions. I feel so true when he says “all you have to do is sit there and watch people using it. So try to understand people through observing them” and when he says “people are able to fix things”. These are so valuable lessons for my career. When I saw the final project from his daughter, I felt I made a very right decision when I registered this 3D printing class. I take ESDGN297 for interest instead of graduate requirement. I believe I could learn as much advance technology as possible from this class.

Blog #2

The “Mother of all Demos” is here: First, watch that first section of the mother of all demos (above), which includes the first computer mouse and cursor ever seen in public. Do you recognize the rough features we use on every computer today in its earliest form? Are you impressed by what he’s demonstrating? Do you think that you would have recognized the importance of this work if you were in the audience at the time?

Then watch this (turn up your sound): In it, Professor Richard Doyle discusses disruptive technological change, open source, knowledge sharing, and ‘creative culture’ among other things. The first 22 minutes is his talk, while the rest consists of questions and chat. What does he say regarding the initial perception of the mother of all demos? Doyle makes a number of arguments regarding the importance of our open source efforts in comparison to models requiring intellectual property. Why do we and why should we share the information we generate? (Or shouldn’t we? Are we missing out by not trying to patent our efforts?) How might we better share our knowledge?


I just watched the first section video three times. I could barely clearly hear what he is saying in the video. But I think I understand most of the demo from what he is trying to show. And some problems which I think most people will have come in my mind as I was watching it. First. Where is the noise coming from? I assume it is from the central processor of the computer. In early days, computers are extremely large even though the capability of them is not too outstanding. There were heat dissipation and noise problems when running a computer. In addition, the noise is likely from the printer of this computer. From this video, I couldn't tell where the text is shown. I don't know if he is using a screen or a projector with printer. It does make sense that he is using a printer since the noise goes with the appearance of the text. Second. What causes the tail following the movement of the mouse? I think the answer for this problem might be the early kinescope. The speed of the movement of mouse is faster than processing speed of computer’s kinescope. That causes the delay on screen. Third. What is the thing on the left of the keyboard? When the camera turned to the keyboard I could see three main parts from the computer’s control board: a keyboard, a mouse and another board which looks like a touch pad. However I don’t think it is possible to have touchable pad at that time. So I have a big question mark on this part. In summary, I would be so shocked if I were one of the audiences at the conference. I am so impressed by the copy and paste command from the demonstration. It could save a large amount of time when doing typewriting at that time. In the other hand, I doubt about the convenience of this “advanced technology”. From the video, I could see the size of the keyboard is much larger than modern ones. I assume that is caused the size of the central processor inside itself. So I think the cost of this early computer is way beyond the average living standard.

From the video “mother of all demo”, Professor Doyle related the creativity of mouse to a true story of his one friend. The story is about how people get together in a contest to generate creativity. He says “one thing that is able to replicate the prototype and it’s another thing that has a culture to actually make it run”. I like the word “culture” he used in his talk. I am in favor of that open source is good not only for business but also for society. Take operating system as an example, more people who can see and test a set of code, the more likely any flaws will be caught and fixed quickly. That is a good point for the security of operating system such as Linux and Mac iOS. In addition, open source software gets closest to what users want because those users can have a hand in making it so. So it is better to create software by hundreds of developers.

Blog #3

Part A) Watch this:

Part B) Check out this: and this:

Part C) Read: and

Part D) Check these:

Part E) These are all examples where 3D printing is encroaching onto other areas of human endeavour which you may not have considered previously. (Civil Engineering, Biotech, Food Science, Fashion) Discuss each in turn. (separate your responses somehow, please!)

How many other examples can you find? (either relevant to one of the categories above or some other field which was not covered)


Civil Construction:

Automated construction: In the end of this TED talk, Professor Khoshnevis said "In the beginning of the previous century around 1920, 62.9 percent of Americans were farmers. Today less than one and half percent of them are involved. The world didn't come to its end as a result of the utilization of agriculture technologies. And the same will be true in case of construction. There will always be better economies resulted from advancement and utilization of technology that just make sense" I am totally in favor of this point and I think this is the belief that supports him to work on this project. This talk reminds me of a movie named "WALL.E". In that movie, it describes that human-being is living in an enormous space station with all kinds of most advanced technologies to support their lives. People don't walk in a result of subway-like vehicles. People don't work since robots could be labors in all fields of daily life. That will be the end of the world for this society. For his research project, I have two questions: first, how accurate the 3D printing machine used in his research is. Safety and comfortableness are the priority of building houses. I don't think time is a big deal in construction. So the accuracy and stability are becoming important for his project. Second, how is he so sure that the cost of this method will be lower than old ways? 3D printing technology is still new to the society. It is just used in high-tech area such as Aerospace engineering when printing large pieces. When apply this technology into other areas, cost is another important concern for companies.

Bio Technology:

While we are still perhaps decades away from fully functioning bioengineered human organs, these latest innovations in solving the human organs problems of these tissues marks a significant milestone in the human society. Manufacturing human organs is the first application I heard about 3D printing technology. "bio-ink" which is made of living cells is a great idea of healing wounds and solving medical problems. In addition, I think it is a smart way to make a 3D skin printer that deposits cells directly on a wound. The quicker the wound is healed, the less pain the patient will feel. Applying 3D printing technology to medical field is the quickest way to benefit human society with most advanced technology, and most directly.

Food Science:

Compared to 3D printed meat or hamburgers, I prefer traditional food made of natural food materials. Even though 3D printing technology is new, remarkable and also so impressive, I don't think it is a good idea to spread this technology out to every field of this society. For most people, the reason of going to restaurants is to have traditional delicious hand-made dishes. There is no point of replacing traditional food with this new technology. I don't see a future for this kind of innovation. However "printing food" is a good idea for military application. Transportation is usually one of the most concerned aspects for a country in a war. A large portion of staff transported is food for soldiers. Especially it is very dangerous to provide food supply to military in some situations. I think 3D printing technology is a possible solution to this problem. Instead of carrying a burden of food, soldiers only need to take a machine which can provide food whenever they need to eat. It is safer, more durable, and more stable.


It is a genius combination of fashion and 3D printing technology. I like the understanding of 3D printing from designer Iris van Herpes, that, "3D printing is an entirely different language." For fashion designer, working with these techniques or gives them a lot of possibilities but also a lot of restrictions. The principle of 3D printing is to manufacture a three dimensional object from a digital model in any design software. So for designers, it is much flexible to think about their ideas in a three dimensional way in their mind. It’s a really big step forward. It changed the way designers work.

Other Examples:

Another example I find which is about 3D printing technology is: preservation of cultural heritage. And

Blog #4

Read This (I suggest you also watch the videos):

A) What are your thoughts after seeing the videos and reading the article?

B) Compare and contrast this technology to that of a closed-source apparatus. What are the benefits and weaknesses of each? How does the cost compare?

C) Find the open source project they refer to starting in the article. How might we participate?


The article is not simply telling a story about some most advanced technology. It is telling the readers what is the true spirit of engineering and design. "Not only did we find a design partner, but we're kindred spirits in that we're both frustrated by the fact that there are some things that just shouldn't be commercialized - they're needs instead of wants - that are." I am interested in engineering is the reason that I wish to make a difference for the world by my own contribution. The purpose of designing robot hands is healing the pain of disables person. However, in modern society, people take use of these smart engineering ideas and make money from them. Also, patent rights keep these revolutionary inventions away from most people, including the ones who might be extremely eager to be benefit from the inventions. But it usually costs way too much for costumers. As we discussed in blog#2, in some aspects, tinkerers are making a difference to move the world forward to a better place. I think Ivan Owen and Richard Van As are the typical "garage tinkerer". Their thoughts, ability and insistence change a boy's life completely. They are real engineers. Their names will be memorized by all people who use the 3D printed rob hands.

Comparison and contrast of open source and closed source: for closed source technology, the end result is that a user is not actually purchasing the software or machine, but purchasing the right to use them. So it usually doesn't cost as much as open source technology to start using it. Because open source is free, it provides consumer the capability to train, improve, and support. So the short term cost of using open source will be higher due to the start investment. However, in long term cost analysis, open source technology has lower cost than closed source ones. Take Liam for example, he needs to buy a makerbot 3D printer when preparing making his robohands. Also basic materials are required for printing. And it is not guaranteed that the parts he printed will fit perfectly as a whole by the first time. But once he successfully has a functioning robohands. No more major cost is needed in the future.

Service of open source software or machine is about using online community. Sometimes it cannot guarantee high quality service and is time consuming issue. For robohands, I think users have to go to Google makerbots forum community to solve their problems if they want to troubleshoot their Replicators. But service is not a big concern for closed source technology software. People often get satisfied response from firm service center.

Another comparison between these two is the influence of innovation. Open source enables hundreds of thousands of consumers to perfect and debug the software. If people is willing share their contribution to the community, it will benefit everyone else among the same community. In spite of this advantage, it may also hurt the community by its flexibility. It is easier to cause security and reliability issues in open source compared to closed source.

To be part of the Robohand group, financing donation is one way. As Rich and Ivan say in their blog, they just started at the beginning of this long journey. They hope to get financing support from people who also has enthusiastic about this project. Contact information is posted in their main blog:

Blog #5

Read This may take some time to read, as it’s rather long. It’s not simple material, but do your best, and we will discuss it in class next week. I’ve given an extra day for this, but I suggest you start reading now.

A) Re-examine the objects you found on thingiverse in your first blog. Assess each one for copyrightable or patentable elements.

B) Look over the things which your fellow students found. If you’re not on the list, please add yourself, and submit it for XP. (see here: Are any of them particularly obvious cases of copyrighted or patented material which have been found by your classmates?

C) Discuss both reasons why you might be interested in the “licensing of non-copyrightable files”.


3D glasses clip is definitely not copyrightable, but might be patentable.

Eiffel Tower is artistic work. so it is copyrightalbe and might be infringing

Math cookie cutter set is patentable and might be infringing

MEG-i-PHONE is patentable and might be infringing

Wolverine Claws in plastic is not infringing

In peers' blogs, I do find some example related to copyright and patent issues. For copyright, world famous landmarks are one aspect of copyright. In my blog, I have 3D printing Eiffel Tower as an example. Also another example is that Carina put replica of Notre-Dame Church of Pairs ( in her blog. Well-known architectures are artistic works. For patent, cjm525 (??What is his name??) found this beautiful 3D printed Ford Engine block ( Piston engine design is not a highly advanced research area for developed countries. These countries have moved on to study aero engines which have much higher efficiency than piston engines. But auto engine design has a long history which contains lots of patents protected technologies studied by these auto manufacturers. It could be a potential threat for these great companies such as Ford, Toyota, and so on.

For the legal purpose, as it says in the article, that granting a license today means that the usage conditions of the object are clear no matter how copyright law evolves in the future. So it is a good way to project the works from creators. For the cultural purpose, licensing non-copyrightable parts of an object encourages people to work on more creative things without the concern of copyright issues.

Blog #6

Read And:

A) Summarize the first article and describe your thoughts about it. What were the key points which you took from it?

B) Why was this years “state of the union” address mentioned in the first article? Does this seem important to you?

C) The University of Virginia is listed in the first article as hoping to distribute 3D printers throughout all educational levels. The second article is an example of how they are changing their Undergraduate ME program. What are the merits of this method? Can you see any flaws?

D) Compare our printers to the printers used at the University of Virginia. If we tried to mimic their program using our printers instead of theirs, how do you think it would fare?


This article gives a quick summary of what 3D printing is and the current status of this technology. 3D printing is becoming a part of daily lives of people in many ways, from entertainment, to food, and to medical applications. Obama cited this technology in his recent speech without much background explanation. It means the technology is not a brand new idea to most people. In addition, I like the point mentioned in this article, the relationship between 3D printing and traditional manufacturing industry. When I first known 3D printing technology I had the same concern about its influence on traditional manufacturing. I thought the future is becoming the one described in movie "Wall-E". However, the author believes that this technology would give rise to new business. I hope which he believes in will happen in the future. Furthermore, I agree that every school in America should have a 3D printer in the classroom in the next few years. Kids are capable to run 3D printers when the machines are fully functional. Although they don't know how to troubleshoot problems of the machines, it shouldn't be a reason to keep them away from this interesting invention. So I think middle schools and high schools should start to cooperate with local colleges. Kids need help on learning to use 3D printers from college students. And it is also a great chance for college students to have practical opportunities. The "state of union" is addressed because the author wants to use some credible facts to show how fast the 3D printing technology is flowing into people's daily lives. Also it shows that this technology is one of the biggest opportunities to rise business. For the thing about 3D printer distribution in University of Virginia, I don't think there are some big problems in their program. I think UVA is like Penn State, doing a great progress on this new technology teaching job. They are both doing a valuable course which is good to both students and the society. However, it seems like UVA is using different 3D printers as those in Penn State. Their machines are more commercial-like. it has merits such as good machine quality, good accuracy, and better durability. But the problem is that these machines cost way too much than fabricators. And it makes a big difference. 20 students sharing 1 machine at UVA versus 3 students sharing 1 machine at Penn State. I think our current machines are better for college students for education purposes.

I think our printers are easier to use for beginners. It will be an advantage to apply this project at Penn State. Currently, some engineering students are complaining that the general undergraduate curriculum are lack of hands-on courses. For example, mechanical engineering students are required to take EDSGN 100, Introduction to Engineering Design before entering majors. EDSGN 100 is a great course to train students with practical projects. However, the next hands-on class will be ME 340, design methodology in the junior year. Both courses give hands on experiences that have truly enhanced engineering education. However, there are four consecutive semesters between these courses in which the education is limited to more theoretical concepts. So I think it is not a bad idea to teach the basics of 3D printing technology in EDSGN 100 classes. In one hand, students connect basic engineering concepts with their practical applications in real-world engineering. In the other hand, 3D printing techonlogy is applying almost everyone aspects of the world. It is worthy to know about it for all kinds of engineering students.

Blog #7

Check out these kickstarter projects related to 3DP.

Much ado about this lately:

This project is currently tied up in legal issues.

Other examples of 3DP related kick-starters:

A) Comment on these projects. Who is suing Formlabs and why? Why do you think the 3Doodler is making such headlines lately? Look around kickstarter for similar projects which were not listed.

B) Do you think kickstarter represents the future of crowd-sourced fundraising?

So, Kickstarter seems like a useful platform, with a variety of projects finding funding through it (though not all, as you may notice). Some people have problems with it, however. Read this:

C) What are the drawbacks of kickstarter? Compare (and contrast ^_^ ) kickstarter to a traditional storefront. Are there alternatives to kickstarter?



3Doodler is a remarkable design in 3D printing technology timeline. This invention connects the imaginary world with physical world in a easiest way. People used to describe an object with words and gestures. And others can understand by imagining the object in their minds. It is neither direct, efficient, nor accurate. Especially for engineers, it often takes the most time to describe an idea or an object in a meeting. So the invention of 3Doodler gives a solution to this problem. It can turn an idea from imaginary world to physical world within minutes. However, some important updates still need to be achieved on 3Doodler. For instance, the ease of use of this tool. new users couldn't take the full advantage of 3Doodler pen since it takes a while for them to get familiar with the weight, the extruding speed, and the cooling speed of plastic. How good a person use 3Doodler largely depends on his experience of usage. So I think current design is just for professionals such as engineers and graphic designer. In my opinion, 3Doodler is supposed to be a perfect learning tool for students, especially elementary students or middle school students. So I am very looking forward to see what the future of 3Doodler would be.

Form 1:

Based on the images provided in this article, Form 1 doesn't output models with better accuracy. However, except for that, I don't see any advantages of Form 1 over 3D printers. Low cost? "we’ve figured out how to do it at a much, much lower cost, making this premium technology available to everyone" is the only answer I get from this article which mentions its low cost. But I still don't know how much it is lower than a traditional 3D printer. In addition, I don't find anything talking about the price of material used in Form 1. Is laser another necessary material? and how much does it cost? Secondly, Easy to use? 3D printers have been used in high school classrooms even middle school. It proves 3D printers are easy enough to operate and maintain. If it is true that Form 1 is easier to use. I don't think it is a worthy-to-mention advantage. Third, it doesn't mention the time that Form 1 needs to print an object compared to 3D printer. I just assume they use the same time to print the same item.

Printxel, ROBO, and Tangibot:

I think ROBO is the best one among these three 3D printers. First, it is the only one which is protected with a case. It makes it more durable and easier to maintain. Also because of the case, it is more convenient to carry the printer. Compared to this, the other two printers do not have this advantages. Secondly, ROBO has the lowest price. It costs about one third of the price of a replicator.


When the first time I knew what is and how it works I became very interested in this website. I thought this website take the biggest advantage of Internet: fast spreading of information. However, there are always problems when things related to raising money or giving rewards. The pros of is obvious. So I wondered what are the drawbacks? I did some research on cons of

First, if a fund raising is successful. Kickstarter will take away 5 percent of the funds. Other than this, Amazon will take away other 2 percent. If the project's margin is slim, this fee could be a significant part of funds. I suggest the percentage number that Kickstarter charges on a project should be based on the absolute funds. For example, case A gets funds 10,000 dollars, Kickstarter will take 3.4 percent of the total funds. For case B, the total funds is more than 100,000, then Kickstarter could take 5.2 percent of it.

Second, Kickstarter offers only "fixed funding" which means that, if you don't 100% make your goal, you get NOTHING. If you don't have active backers who REALLY, REALLY want to see your project succeed, it won't.

Third, Kickstarter ONLY accepts donations via Amazon payments. a lot of potential backers did not have Amazon accounts and did not want to create them just to donate to my project. Amazon payments has a strict policy that no one can "pay themselves" to fund a project. Even if the money comes from a genuine backer via a personal check, you cannot pay it to the Kickstarter project. If you do attempt to "pay yourself" in this way, Kickstarter will cancel your project and blacklist you.

Blog #8

Review the blogs #4 and #6 of your teammates first and then your classmates. I want you to find and link to the 3 most insightful posts for each blog (#4 and #6) (other than your own). Include why you consider their posts to be particularly thoughtful. IF you were giving away XP, who would deserve more XP for their blog posts, and why?

Thoughts on interesting posts:

best blog#4:

Yayi Yang:She highly praised the contribution on 3D printing technology from Oven and Richard. They spent their lifetime working on technologies that could help disabled people out of trouble even though they don't expect to gain the economic benefits. There are people who benefit the society with their intelligence.

Chris:He created a good table shows the comparison of open source and closed source. It makes the advantages and disadvantages clear to read. With this table, Chris argued the reasons of advantages of closed source. This blog has the most insightful thoughts on two kinds of source. So my extra XP will go to Chris's Blog #4

Mark Keller:There are some very useful links in the last paragraph of this blog. Especially the robohand link on Also Mark provides the websites for donations. It is critical for the future development of the project. The society will benefit from efforts from every single person.

best blog#6:

Michael Bilyk:I like his thoughts about applying 3D prints in Penn State classrooms. The less tolerance and price advantage. We don't have printers with amazing tolerance. So that would be a major concern for education purposes.

Chris:He wrote "Some interesting things are that while our printers often break, by fixing them we learn how they actually work and how to service them - this is something the students at the University of Virginia may lose if they are using expensive state-of-the-art printers". That is an very important point. I will say "Fixing leads learning". 3D printing gives engineering students a better way to understand concepts in textbook. Similarly, fixing the printers helps students to know how the machines work.

David:In his last paragraph of blog#6, David provides a solid evidence of the comparison of costs of two different 3D printers in Penn State and UVA. There is a 100 times on price differences.

Blog #9

Read this:

This is one example of a ‘using photos to create 3D models’ technology, as well as a laser-scanning method. Discuss laser-scanning based models as compared to photo based models. Can you find any examples of a photo based method which are open source?


I am not familiar with neither of these technologies. So I make some research on the comparison of laser scanning based models and photo based models.

In general.

1. From invention point of view, laser scanning method is newer than photo based method.

2. From a quantitive point of view, laser scanning approach provides more acurate results than image based modelling.

3. time required in laser scanning is about half of that needed in photo based models.

4. With relation to results, image based modelling offered great results with a wide range of applications: from an interactive environment to metric maps and wireframe models ready to be plotted.

I found a research paper which talks about the difference between these two technologies for 3D modelling cultural heritages. As a result, the question which technique is better than the other can not be answered across the board. It will be a mix of factors and elements such as own characteristics of the object, applicability, economical support, client requirements, etc, which will provide the best strategy. At the end of this paper, it shows a table which clearly states the advantages and disadvantages of each technology.

3D modeling from laser scanner 3D modeling from images.
No semantic information (-) Semantic information (+).
Inaccurate lines and joints (-) Accurate lines and joints (+).
Poor colour information (-) Good colour information (+).
Prompt and accurate metric information (+) Hard-working and slow metric information (-).
Potency and automatization in data capture (-) Low potency and automatization in data capture (-).
Excellent technique for the description of complex and irregular surfaces (+) Time-consuming technique for the description of complex and irregular surfaces (-).
High-cost technique (-) Low-cost technique (+).
The 3D model is an entity disorganized and without topology (-) DThe 3D model is an entity organized and with topology (+).
Light is not required to work (+) Light is required to work (-).

So in general, each technique owns its advantages and disadvantages at different working fields. In many cases, a combination of both techniques might be a useful solution.

Blog #10

Mbilyk talked about my blog 4.

MarkKeller talked about my blog 6.

blacklaser talked about my blog 6.

Vatlark talked about my blog 4.

YaqiYang talked about my blog 6.

A couple of classmates think that I did a good job on writing blog. I appreciate they spent time on reading my blogs. As well as I had an interesting time reading other's blogs. When writing blogs, I prefer to do a brief research on the topic I am going to talk about beforehand. It helps me to gather useful information from others' thoughts. After reading a few comments I will have a general idea of my blog and a basic outline. I hate writing without thinking. That will be meaningless. In addition, I hate copying other's work. The only thing that attract people's attention and interest is the writer's own work. So that is what I want share with classmates.

Blog #11

Given your experience with our OHM RepRap design, are there any parts in particular that you would redesign? How might we improve on what we have?


1. My key word about experience with OHM Reprap design is: Fixing. Until the week after spring break, our two prints are not functional to print. Our team spent nearly 40% ~ 50% of class time on fixing two printers. In general, two printers had similar problems. So I will focus on only McDonalds printer in this section. There were some very common problems that happened to McDonalds. So I will talk about what the problem is and what the solution is. I think these are major problems that might occur to a printer. (on-going section)

  • Problem: hard to assembling frame. hard to fit each rod into optimum position.

^solution: It is easier to assemble the two triangle parts first. Then using the horizontal rods to connect two triangles.

  • Problem: belt is loose in X-axis

^Solution: find the good tension. Also it is likely the bearing that the belt is running on is wobbling. So make sure the screw is secured.

  • Problem: plastic is not extruded consistently.

^Solution: First, check is the two bearings are pushing against the plastic and sending it into the hot tip. If not, check the screws. Second, two gears might be sliding on each other. Sanding is a solution to reduce the sliding. But it is better to print higher quality gears that match with each other.

  • Problem: hot tip is not hot.

^Solution: three thermal wires are suppose to be attached on the hot tip. Be careful when working with these wires. they are very easy to come off.

  • Problem: how the extruder base is connected with the piece of mental plate.

^Solution: recommend to use big washer. Small washer could crack the entire plastic base. The result is that there will be a crazy gap between the base and the mental plate.

  • Problem: X-carriage wobbles on x-axis.

^Solution: the long x-axis rods might be not parallel. It is also possible that some bearings of the x-carriage are not sliding on rod. carriage wobbling can be found every time the carriage changes direction during printing.

  • Problem: Belt is loose on y-axis.

^Solution: First, check the belt tension. When the tension is too much it is necessary to change the zip tie. When changing zip tie, make sure new zip tie is on before cutting off the old one. This tip makes life much easier. Third, check if belt is parallel.

  • Problem: y motor is not spinning well.

^Solution: Due to the pulling force from y belt, y motor is sometimes spinning while against the piece that holds the motor. This makes the spinning not smoothly.

  • Problem: y carriage is not moving smoothly.

^Solution: I think y carriage is the most important part in entire printer. there could be many problems in y carriage. First, rods could not be parallel which causes the y carriage wobbling. Second, some bearings of y carriage could not slide on rods. Third, it is also very important to find the right distances that match the bed, carriage, and rods.

  • Problem: problems with circuits, chips and electric board.

^Solution: be aware when dealing with circuits. Pay attention of the directions of wire.

Improvements of design: make this piece "x-end-bracket_1off" thicker. This piece carries too many small parts. there are a lot of screws and nods on it. with current thickness, it is very easy to break it when screwing, especially holds are not perfect round.

Blog #12

Our next big projects on the horizon are the dual extruder and the filament recycler. If you had to focus on one of those two projects, which one would you push and why? What are the relative merits and motivations behind choosing each? How does each advance the RepRap project more generally?

Blog #13

Name one or more topics related to 3D printing which you wish we discussed in greater detail during the course. How might we evolve the course in the future?


I am very interested in how 3D printing technology is applied in real physical world, especially in real mechanical industry. What we learned in class is about how 3D printing works with plastic. However 3D printing technology has been applied to many field such as Aerospace Engineering, material science, Bio engineering. In these industries, 3D printing needs material such as iron and steel. there definitely is a difference between those 3D technology and the ones we learned. So I think it will be useful to introduce these advanced application about 3D printing on future's classes. Because the basic principles behind these applications are the same. So it might be a good idea to relate the classroom with outside real world. In addition, Penn State has good reputation on Engineering department. Engineering students from Penn State should be trained with this strong ability of applying the knowledge learned in classrooms.

Bonus Blogs

Bonus Blog #1

Read this great idea from Aerospace industry. It also includes a cool video about a giant robot which has 6 legs.

Also this is the twitter of Tomas Rousek who is a space architect and is charge of this great on-going project.

The question is: Is it possible to 3D print moon base with lunar soil?

3D printing moon base with lunar soil would drastically reduce the amount of materials needing transport to the distant location and would make expanding the base far faster and cheaper. Looking to use the technology in colonizing the moon, Dini created a simulated lunar soil mixed with magnesium oxide to create a base material. Then, using structural salt as a binding agent, he was able to create a stone-like solid. Enrico Dini is an Italian inventor, also is chairman of the company Monolite UK Ltd. Dini has developed a huge three-dimensional printer called D-Shape that can print entire buildings out of sand and an inorganic binder. The printer works by spraying a thin layer of sand followed by a layer of magnesium-based binder from hundreds of nozzles on its underside. The glue turns the sand to solid stone, which is built up layer by layer from the bottom up to form a sculpture, or a sandstone building. Read more about this at here

Just how fast will the printer work? Dini said the current printer builds at a rate of around two meters per hour and the next-generation design should attain 3.5 meters per hour, completing an entire building in a week. Knowing the current capabilities of 3D printers at a small scale, this technology has the potential to create buildings far more massive, structurally strong than any we could hope to lift off the surface of earth… and hey, they won’t have to be shaped like a rocket. To learn more about the project, read more at this report from the European Space Agency.

Bonus Blog #2

In this blog, I want to talk about an airplane powered with solar energy - Solar Impulse Alpha. See photo here:

Solar Impulse Alpha is a Swiss long-rang solar powered aircraft project being undertaken. The project eventually hopes to achieve the first circumnavigation of the Earth by a piloted fixed-wing aircraft using only solar power. The project is led by Swiss psychiatrist and aeronaut Bertrand Piccard.

This month, the airplane will fly across the united states on sunlight alone. In 2015, it will circumnavigate the world. By that time, there will be a historical record in aviation history.

In my opinion, the future of aviation is "fast, private, and environmental-friendly". In recent year, business jets market is booming up, especially in Chinese markets. That's the sign of faster and more private airplanes. For Solar Impulse Alpha, it is chasing the goal of private and environmental-friendly. The aircraft is constructed entirely from carbon fiber joined by high-performance plastic screws and bolts. the materials are light yet strong enough to give Solar Impulse a wingspan of 69 spans-almost exactly that of an Airbus A340-500 passenger jet. However the plane weights just over 3500 pounds.

Then how the airplane is powered? engineers use nearly 12000 silicon solar cells over the main wing and horizontal stabilizer. According to Popular Sicense. The cells generate an average of 50 kilowatts over a 24-hour period, sending electricity directly to the motors when the plane is in flight and directing any excess to four lithium-polymer batteries.

The reason I am interested in this topic is that this technology can save large amount of fuel in the future. Similar technology is also under developing at NASA. See photo here:


Primary:Open Hybrid Mendel Construction

Secondary:Makerbots Troubleshooting