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.

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.


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.

3D Objects, Engineering, Redesigning Something That Exists

Redesigned Conceptual Bookend

Some time ago, I saw a beautiful design of a push-pull bookend. It was only a concept. The original concept had a good design, however it was lacking many ergonomic qualities.

The original design had about 8 indentations for pens/pencils; a small drawer, probably to store one eraser; a much deeper depression in the central box (objects would have “drowned” inside it); no way of grasping it so that it can be moved etc.

My new design has tackled some of these issues. Now there are many more indentations for pens: these are both on the front as well as back (you must realize that the sides don’t make sense for keeping pens). The box in the middle is not very deep (now the objects do not have a chance to hide). The drawer is at the back and much larger. Many more things can now be kept in it. But the best of all, when there it needs to be stored away, the book case can now be held firmly with two hands.

I have the videos of the designs for the old model and my redesigned model (the good anti-aliasing in Rhino, can  make a piece of rubber look like glass!) Below are the two models compared with and without the stationeries (this is the correct spelling). The old concept is on the left and my concept is on the right. The last image is the back view of the new design.

bookend new


3D Objects, Engineering, Redesigning Something That Exists

Redesigning something that exists – 1B (Multi-tool)

Continuing with the 7-in-1 multi-tool, the New Design has a lot less parts: 23 only! This includes the screws, now reduced just to 3. As with the previous model of the clock, I have a video for this model as well (mentioned again at the end). The new design is much more efficient to assemble. Take a look at the part count in the image below.


For DFMA, the new assembly efficiency has increased to 43% and design efficiency to 36%. For AEM, the assembly efficiency is now 67% and design efficiency is 56%. But the Part count design efficiency has increased to a whopping 83%. The assembly time has reduced to 160 seconds.

Check out the perspective view of the 3D model of the new design, and match the parts with the first image:

exploded view

Of course, the PCB is only a solid object here and unconsidered for the conducting pathways. The project was overall a huge success, because the labour cost was reduced by 5%. This is not a lot for one multi-tool. But if we consider the thousands they make each year, SWISS+TECH can save a lot with this new design.

Here is a video of the redesigned and assembled 3D model in turntable view. I am still working on animating the assembly sequence. It will be available soon.

P.S.: My friend Hsin-No Lin contributed a lot while working on the DFMA and AEM calculations. He and I worked as a team of two during this project.

Engineering, Redesigning Something That Exists

Redesigning something that exists – 1A (Multi-tool)

7-in-1 Multitool by SWISS+TECH

(BodyGard® 7-In-1 Platinum Series Emergency Tool)

This project began as a part of Professor Andrew Gadzic’s class, Design for Manufacturability. The goal was to use Boothroyd and Dewhurst Inc. DFMA (Design for Manufacturing and Assembly) and Hitachi AEM (Assembly Evaluation Method) to determine the approximate assembly time and labour cost associated with the current design.

The current design has a pending patent according to their instruction manual. Take a look at the features from their video. It is quiet fascinating. (Keep the volume of the video high enough and you will also, probably find it funny near the end because of the acting).

SWISS+TECH has made some very useful products which are helpful during emergencies. However, it seems that they have probably had to make a trade off between the design and operability. But fear not, SWISS+TECH, the new design concept, after careful consideration and analysis, not only reduces assembly time and the associated labour costs, but also removes unwanted parts and makes it look as good as the original one.

The current design, when given a closer look, has about 39 parts (the total number of screws used are 9), with a structure sequence as shown in the image below:

part count

Currently, through DFA method, the model has an assembly efficiency of 36% and design efficiency of 17%; through AEM, the model has an assembly efficiency of 65% and design efficiency of 30%. Finally, the model has a part count design efficiency of only about 46%. From our estimation, it takes about 326 seconds to assemble this model one time. That is a lot of time, especially if it is assembled by humans.

The newer design is aesthetically the identical twin (with minor differences, here and there), but economically, a saver and has the assembly time cut by more than half.

Check out the newer modified design here.