CNC and Machining, Creative, Engineering

Engraving Aluminum

I wanted to see if it was a good idea to engrave soft metals. Turns out, it’s a great idea. Not only is it easy, but also incredibly fast.

Even better is creating gcodes. In fusion 360, even though there is an option for engraving, it is not possible to use this with an engraving tool, because engraving is still considered milling by the software.

An easy way to get around that is by using the Trace option. And since I was using a simple sketches, it was extremely convenient to select the tool-paths. It is actually easy to engrave 2D sketches by using the trace option, rather than the engrave option. Engrave option is good only if you need a bit of a depth.

My choice of material was aluminum, and yes, they are dog tags.

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I had to trace twice on the othermill because of the uneven arrangement of the material, yet it still took only about 25 seconds for each trace, i.e. both the sides were engraved in less than 2 minutes!

No, I did not speed up the video.

CNC and Machining, Creative, Engineering

Aluminum Tree

As shown previously, Aluminum is a relatively soft metal, and it can be milled easily. This time, it is  a 4 in. x 4 in. sheet of aluminum. I simply used a previous dxf file created for milling plywood, and reused the same gcode.

The process took only about 30 minuted to mill, and the output was clean, even though I had used a 1/16 in. ball end mill tool. Had I used a smaller sized tool, it would have been much more precise, but it would have definitely taken hours to finish the job.

Here is the time lapse video of the process. There is a bit of engraving at the end, but it is not very satisfying. I will make another one showcasing the engraving soon.

CNC and Machining, Engineering

Circular Milling

Aluminium or Aluminum is a relatively soft metal. It is light, but also durable, making it an excellent material to create useful parts for things used in everyday life. It had been a while since I tried to test different kinds of milling using Autodesk Fusion 360.

Fusion 360 has a really good way to create GCODEs for circular objects. It is similar to contour milling or profiling, but specifically meant to create circular or cylindrical objects with minimal wastage of materials.

I decided to make a couple of aluminum rings. Since a metal was being used to mill another metal, it was very important that the distance between each subsequent each step over was very small. Unfortunately, this meant that the process would create aluminum powder instead of swarf, and I had to be very careful while cleaning the OtherMill once the machining was completed.

Regardless, the finishing was beautiful and it actually did not need any extra polishing.

 

CNC and Machining, Engineering

Can you mill floor?

It depends on what you mean by floor. The floor at one’s home is made of a variety of things: tiles, concrete, granite, marble, limestone, wood,  cork etc. Most of these can actually be milled to create beautiful pieces of artwork. Some of them can also be milled to make useful things.

Take linoleum, for instance. It is made from substances. These generally include solidified linseed oil, solid pine resin, ground cork, finely pulverized wood, and limestone, usually on a  canvas backing. An excellent use of these is to make stamps.

I simply created an SVG file, imported it in Autodesk Fusion 360, and made a CAM gcode file for the OtherMill.

Well, milling is fun. However, milling linoleum is a special case. The dust created from the milling is very much like powder. So it is very difficult to clean the OtherMill after the milling process is complete. This is also the first time I used more than one bit to mill the material, as some of the parts needed a finer milling tool.

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Of course, this stamp is for display purpose only. The actual stamps will always be mirrored so that the text can be read once a paper is stamped.

3D Objects, CNC and Machining, Creative, Engineering

Jansen Linkage

Wouldn’t it be more appropriate to use a laser cutter to cut acrylic rather than using a small desktop CNC (Computer Numeric Control) machine to tediously mill it to a desired shape?

Well, the answer is not obvious to sometime who doesn’t care about having unfinished edges.

The difference becomes more obvious when using transparent acrylic. Using a laser cutter, melts the acrylic, leading to the “cut” sides to look more or less like melted plastic, and opaque. Using a CNC machine, on the other hand, gives it a smooth and nearly transparent (usually it’s translucent). Check the image below and you can see the finish.

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I decided to make a Jansen linkage model using clear acrylic, a piece of cardboard and some 3D printed parts.

I used Autodesk Fusion 360 to design the shapes and linkages, and also create a gcode file thought is CAM component. Finally, I used an OtherMill to mill them using a 1/16 inch flat end mill. The results were spectacular. The milled surfaces were smoother than any any piece of acrylic cut using a laser cutter.

The brown cardboard was etched and cut using a laser cutter. And the silver pins were 3D printed on an Ultimaker, using an STL file created using SolidWorks. The image of the final prototype is below:

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It doesn’t make sense to have a fixed Jansen Linkage model. The whole purpose of having it is to make it look like it is walking. Connecting two or more of these models can make it look like it is walking with more legs.

Here, check it out in the video:

 

Engineering

A project from the past: ARTEMIS

High-altitude balloons are unmanned, filled with light gases (either hydrogen or helium), initially released from ground level. They can be used until they reach the stratosphere. Due to their comparatively low rate-of-ascent, these balloons are perfect candidates for precise measurements of sections of the atmosphere. High-altitude balloon experiments and activities in India are very rare. This project makes use of an alternative use for high altitude balloon. Imagine a situation where an area is struck with a disaster (natural or unnatural). Usually at such times, there are constant telecommunication problems. This is the main drawback of any such systems. A distress signal must be sent to rescue centers and ground stations to receive help. Data from the disaster struck area must be collected and sent for analysis. A possible solution is ARTEMISAirborne Remote Measurement and Information System.

A small box containing electronics, including measurement equipment like sensors and transceivers was attached to a set of 3 large high-altitude balloons (making it airborne). This was tethered to ground to make sure that it wouldn’t fly away. Multiple ground monitoring and control stations were set up to constantly monitor the transmitted data. Data presentation was available in these stations. A Cut-down altitude was set in the ground control station. When the balloon reached the cut-down altitude, i.e. the balloon was detached from its tether, a sub-system known as the Cut-down mechanism (made of heated nichrome wire) would separate the payload from the balloon. The cut-down mechanism was also an emergency Flight Termination Unit (FTU) in case of system faults. A parachute attached to the payload minimized the rate of descent and provided a safe landing. Since the test height was not in thousands of meters, a GPS system for recovery was not necessary. Finally, a recovery team could be dispatched to retrieve the payload. The payload could be serviced and reset for the next flight.

Doing a few tests, we determined that the payload was constrained to 300g. This forced us to use three baloons which could expand upto 3 meters in diameter, filled with hydrogen (since Helium was very expensive). A XBee Pro S2B was used as the communicating device at the airborne system, and at the ground stations. The FTU which  was a nichrome wire, was heated by a sudden surge of current provided through a Li-Po battery. The battery also powered the microcontroller used to control the FTU and Zigbees.

The main advantage of using a high altitude balloon is that it increases the range of communication. For instance, if the range is rated as 2 km line-of-sight on ground, then we observe that the same range increases if we consider one part of the system at an altitude.

Below is the launch sequence of the system:

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Creative, Engineering, Interactive Design

Graveyard Escape- The Game controlled using Wearable Tech

The term project of my Costumes as Game Controllers class had an awesome team of 4. There were two more teams. My team mates were Olivia, Samvid, and Yuan (White)

While our instructor had given us a task of watching a movie among a few choices (Our team chose The Fifth Element) to learn about how costumes impact emotions. After watching the movie, we were asked to write down a list of emotions. All students wrote down the emotions. We had to pick one emotion, based on which we had to build an entire game that used costumes as it’s game controllers. The emotion we got was:

Upset

Yes, we were upset the we got that as our topic. We then had to do mind mapping, a way of generating words that somehow connect with “upset”

We came up with so many words that had even the slightest of connection with the word: sad, crying, suicide, murder, death, graveyards etc. There were also words that had nothing to do with the word: education, college, crows, gambling etc. The most tangential word we got was

 Happy

How about making a game that begins sad and ends happy? No! That is too much of a cliche. Well, then there could be a factor of choice, begin with sad and end with sad or happy, deepening on the choice. That is what we did with our game:

 Graveyard Escape

 The entire game was made as a choice for one man who had to get out of the graveyard where he was trapped.

The story is pretty long and had to be divided into three acts. In the first act, the man was transformed into a cat, in the second, a crow.

The game began with a simple ritual of placing flowers in front of a gravestone, as in the image below. Conductive fabric was used to make this mechanism.

The game was played using a cat paw glove on one hand, and a black crow wing on another. The claw was used to attack the enemies on the ground, and the wing was used to fly. Below is an image of our instructor trying out the costume game controller.

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Finally, the images of a user testing the game while wearing the costume (the game was made using unity):

 

 

3D Objects, Engineering, Interactive Design, Redesigning Something That Exists

Utility Wrist Band

While working on the term project of my product design class (Design Strategies), we were randomly grouped into teams of 3. Each student had to come up with a product, and then decide which product is the most viable, and proceed with it.

After thinking of the feasibility of product development, we decided to go with a product called walk clean.

The concept was that a wrist band is only a fashion accessory, but has potential to be more. It is worn by many people; imagine a world, where it could be used as a utility device!

Walk clean is a utility wrist band that has a hollow compartment inside it. The compartment (for now) is used to store gloves, mostly meant to be used by a person who does not want his/her hands to be contaminated.

The wrist band was made using 3D printers with the material TPU.

Two iterations were made: In the first one, the band was supposed to be two different pieces, joined in the middle. However, the flaw with this one was that it would not create a circular shape around the wrist. Here are the images rendered using Rhino.

The following images show the first 3D printed prototype of the product. The glove could be easily placed inside the band, but the shape could not be kept. Also, there was space only for one glove.

The second prototype was designed as an incomplete hollow ring. This gave the band a circular shape. The hollow inside meant not just one, but two gloves could be placed inside. A simple piece of acrylic was used to join the ends together to make a complete ring.

Clearly, the size is larger than a regular wrist band, and the outer surface looks unpolished (unlike the previous one). However, for about 80% material infill, the prototype is very sturdy. The lesson from building this prototype is that TPU is very flexible, and it is very easy to make hollow objects with it. This means, that a “human” sized wrist band can be made with a little bit more effort while 3D modelling.

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Above is the image of all the things the prototype comprises of: the wrist band, a pair of gloves, two rubber bands, and an acrylic piece.
This video shows how the  second prototype o

f the utility wrist band works.

CNC and Machining, Engineering

CNC Milling – Machining Wax

The first time I saw a piece of machining wax, because I did not know any better, I thought it was ABS!

This design was made on Autodesk Fusion 360. A g-code file had to be created in order to read the file in otherplan. Otherplan is the software that operates OtherMill Pro. One of the important considerations while creating a g-code file is to make sure that the feed rates, ramps and other constraints are optimally set (such as the kind of tool that is being used).

An easy way of creating g-code files is through the use of dxf files (which are a kind of vector files). They can easily be created using adobe illustrator or autocad. Regardless, once a dxf file is converted into a g-code file, the otherplan can read it. The milling can take from a few minutes to a much longer time. The tool size, tool path, and the spindle RPM are the ones that determine the time.

This design was made because the machining wax I had used was almost purple. And since I work at the NYU MakerSpace, I felt that it was appropriate to mill the logo.

Engineering, Interactive Design

Soft buttons and Capacitive Switches

Adafruit Flora is a very easy to use. It is also easy to operate. In simple terms, Flora is an arduino that can be worn.

One of the first things that comes to mind while wearing electronics is that it should not be heavy and it should not be physically hard. Hence switches should be made soft.

Soft buttons can be made using foam and conductive tape. When two tapes are used, one acts as the conductor and the other has to be used as ground. when both touch, a circuit is formed and something can be triggered or activated.

Capacitive switches can be made with conductive fabric. This one is simpler than soft switches. A simple touch can trigger the switch! What I mean to say is that the fabric is the conductor, and anything that can conduct electricity is ground.

A simple test can be performed by connecting the Flora with NeoPixels. In my example, when the capacitive switch is triggered, the neopixels glow red, and when the soft button is pressed, the neopixels turn blue. Otherwise, they remain green. Here is a link to the working video.

The image shows the entire setup:

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