2D designs, Creative, Engineering, Interactive Design

Circular shapes

Circle― the most beautiful 2-dimensional shape, the infinite sided polygon…

No! No it’s not; it’s a limit curve of a regular polygon say the math nerds.

Alright, I agree. But as long as we agree that circular shapes are very pleasing to the eyes. Any object with curved corners looks great― phones, mugs, rings. Even throughout history, circular shapes have influenced the progress made by humanity. I will stop now and get to the point.

So, while designing the Elmentory Atom, I had the option for making these plug and play devices in any shape. Atom itself has 4 types of units. Originally, the plan was to make each unit a different shape. But after doing some research, it was evident that different shapes would be a bad idea. Circular was the best choice.

But, because we were using tiny electro-mechanical components to build them, each unit could not be perfectly circular, but had to have flat edges to accommodate for the rectangular connectors. I don’t know if you can see them― each of them is 35mm or less in diameter― in the images below, but the black connectors align perfectly with the colorful boards.

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Apart from the shape, the other important feature was the symmetry of each device. Each component was placed in a particular spot on the board to make the board look symmetric at least along one axis.

Finally, the most important part (I’m writing this last instead of first because of the title) was to make sure the devices were easy to use. Each of these devices can be connected to one another. But if they are connected wrong, it would not work, yet neither will it harm the user, i.e. the child playing with them.

Each device had a name on the top, and a specific color based on how it operated. Some inspirations were taken from common objects such as traffic lights to specify the color. The bottoms of the devices were mostly white, and helped the child identify if they were connecting the devices correctly.

This project was fun, because I had to literally think like a child to see what could go wrong. Fortunately, there were also several usability tests made with real kids during development to improve the product before releasing it.


3D Objects, Creative, Engineering, Redesigning Something That Exists

Infinitely Remoldable Substance

When I was working on Mobility devices for the Elderly project, my team and I had to do design research on why/how the seniors in the greater New York area used assistive devices for ambulation. While we uncovered many different insights, one of the thing that struck out was the ergonomic nature of the device itself.

Seniors used walkers, canes, rollators, shopping carts and also other make-shift devices to support themselves when they moved from place to place. No matter what device they used, it had to be comfortable to use. Comfort here doesn’t equate to the psychological feeling of stigmatization, rather, it is the congenial ease in using the device itself– hence the ergonomic nature.

When working on the ‘Adaptacane‘, we came across many materials to use it for the grip of the cane, such as memory foam. However, the best material that one could possibly use while making the grip of the cane is polycaprolactone (try saying that a few times). This material, sometimes shortened as PCL, can be molded by applying heat from, say hot water, and shaped into anything, including the shape of the inside of a gripping hand. It is also biodegradable!

Let’s look at an example:

The best part of using this material was that it could be remolded any number of times. The handle (white) of the adaptacane prototype below was made using PCL.

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Pretty cool stuff!

3D Objects, CNC and Machining, Creative, Engineering, Redesigning Something That Exists


The 2010s can be divided into two eras — the time before and after fidget spinners came to existence. The weird part is that they came out of nowhere, and now they don’t seem to exist at all!

In fancy MakerSpaces, it is quite common to make these using 4 cylindrical ball bearings, and printing the shell. However, where’s the fun in boring old 3D printing? Besides, it takes quite a while to print. And not to mention, there is always going to be tolerance issues, because low fidelity printers are not supposed to be accurate.

Truth be told, using a thick piece of acrylic and laser cutting is perhaps the fastest way to do this. But a laser cutter is limited to cutting at most an eighth to a  quarter of an inch, beyond which one will have to repeat the trace on the piece of acrylic. And this would cost, surprise, surprise… the tolerance.

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Regardless of the backstory, I was thinking of using multiple machines to make something. The plan was to use my trusty desktop CNC milling machine along with the water jet. I used delrin to make the case or the shell, and the caps. Then, I cut a thick piece of steel slab into circles, to give the spinner some weight.  All in all, it worked exceptionally well!

P.S. I’m not making another one, not in this way… ever. Also, I don’t think fidget spinners make good Christmas presents.

2D designs, Creative, Engineering, Interactive Design

Holy Diver

With Halloween coming soon, I though about posting a wearable game that my classmate Sam and I made some time ago. It is called Holy Diver.

The principle is that a demon is throwing fireballs at you, while you can catch them and throw it back at it, or defend yourself by joining your palms. However, if you get hit thrice, it is game over!

The game is very small, and it’s prototype can be downloaded here.

The game ran on unity. Well, the song Holy Diver by Dio was meant to be played in the back while playing the game, hence the logo on the costume. It was one of the first time I used a laser cutter on fabric. Laser cutters can be handy in making burned effects on clothes. A costume was made for the game, using Adafruit flora.

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CNC and Machining, Engineering

Water-jet cutting

Water-jet machines are a special class of CNCs which use highly pressurized jets of a mixture of water and powdered abrasive, such as garnet. This can be assumed to be similar to Laser Cutters. They can only cut objects in 2 dimensions. However, unlike a laser cutter, the water-jet can cut through thick metals like steel, aluminum, and even carbon nano-fiber sheets!

Here is an example of a circular disc I cut from a steel slab for a funny little project, which uses the delrin from a previous post.

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Here is another example of water-jet cutting to make a keychain.


Engraving Tools

Engraving on metallic surface doesn’t necessarily need an engraving tool. Depending upon the kind of application, the type of tool can be different. For example, when milling PCBs, a engraving tool can be substituted for a flat end mill tool for better accuracy when it comes to having very minute spaces between tracks, pads or holes.

It is not just the size of the tool that matters, but also the type of the tool used. In a previous post, I had used an engraving tool. Here is just an example of how different it looks when a different tool is used to engrave on a aluminum surface. I used a ball end mill, which is used to give effects of curving or filleting on the edges of the object. Spoiler alert: it did not turn out as I wanted it to.

Check out the video; the process is short and quick.


Making Printed Circuit Boards the old way

Printed circuit boards (PCB) are used in every electronic device.  The PCBs, before they show the circuit itself on the board, they contain a layer of copper deposited on them. This is later removed – etched, to be exact – in the unwanted areas, and become the “connecting wires” within  the electronic circuit. These days, milling machines are used to remove the copper accurately so that human errors are minimal.

Of course, if the design itself is flawed, no machine can compensate for that kind of human error.

Before milling machines were invented or, before it was affordable to use milling machines for PCB etching, the process was done using chemicals. It is still done in that way, but not extensively, as the process has a tendency to remove all of the copper if not done carefully.

The video below shows the simplest way to etch a PCB using household Muriatic acid, ferric chloride, and a clothes iron.


3D Objects, CNC and Machining, Engineering


Although, it sounds like someone’s name, Delrin is actually the name of a plastic brand. The plastic itself is called polyoxymethylene, which happens to be a thermoplastic. It is relatively soft when you compare with metals and wood, however, tougher than ABS, making it an excellent machining material. Ever seen a  white colored gear? It is made of delrin. The plastic can also be used to make other objects like handles, guitar plectrums, toys, machine parts etc.

I was working on a CNC based project, and has to mill parts for the final product. In this post, there are only two milled caps. I will make another post on the giant flower-shaped hole in the middle, and the completed project in the future. So, for now, there is this video with royalty free YouTube music and some background noise. The video below shows the milling of delrin, using the circular milling method.

Creative, Engineering

Laser cutting and engraving of Lower Manhattan and Downtown Brooklyn

Some time ago, we were testing the biggest laser cutter, the universal, which has a bed size of 2 ft. X 4 ft. We wanted to do an interactive project for little children to play at the New York Makerfaire.

A map of Downtown Brooklyn and Lower Manhattan with some of the most iconic buildings and monuments was decided to be the best choice. The children would press the monuments and a display would show the actual photo and a brief description of it.

But before making the actual prototype, we decided to test it out on a test piece of acrylic. It came out pretty good.

Here is the video of the test:

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.