how we designed

bulkey code wallet?

Reading time: 17 minutes.

If you’ve landed on this article, you probably want to learn more about BulKey Code Wallet™. Here we have tried to tell you the path we went through to create this amazing product

Read More: How it started? The BulKey Code Wallet idea

After discovering that there was no similar product on the market to solve our theft problem, we decided to create the solution.

The first step was to define its idea and goals. At first, they seemed simple:

  • To Have a 4-digit code
  • The code to be sufficiently secure.
  • To not be able to randomly self-change the code
  • For it to be Pocket Sized
  • To have room for over 80 banknotes
  • To have a place for keys
  • To Have built-in Bluetooth tracking and RFID protection.
  • To be attachable to different places
  • To have an affordable price.

Once we established these requirements, the design phase began and lasted overa year.

1. The design of the locking mechanism.

1.1. Electronic lock with batteries

Since our company ( has many years of experience in electronics and locking systems, our first idea was to create a wallet with an electric lock. But that meant we had to fit both the battery and the locking electronics in the wallet.

After analyzing the options, we have, we came to the conclusion that all of this cannot fit into the dimensions of a regular pocket-sized wallet with enough space for bills and cards.Another aspect with an electronic locking system is that the wallet would become very expensive, and our goal is to make it affordable so that everyone can protect themselves from pickpockets.

An additional problem in this initial idea is also the battery. It would be an additional part that you should keep an eye on. And if you don’t check it, there is a danger that the battery will die and your money will be locked in. We don’t want to create an unpleasant situation where you can’t unlock your wallet when you need to.

1.2. Mechanical lock

Thus, after dropping this initial idea, it became clear that the lock would be entirely mechanical, not electronic.We started to think about the goals we set for ourselves at the beginning.

  • The first goal is that it should be a 4-digit code.

The extra 1 digit over all other 3-digit locks on the market gives 10 times more security. In this case, the possible combinations are not only 1000, but 10,000. This makes your choice of code much wider, at the expense of only 4 digits. And they are as easy to remember as the pin code of your bank card.

  • The second goal is that the code mechanism is sufficiently stable.

What do we mean? Even before we started designing, we looked at the feedback of people who used other code wallets. The most common complaints were that the code on their wallets would self-change under heavy mechanical shock. Imagine the awkward situation where you accidentally drop your wallet on the ground, then you enter the correct code, but it turns out that it no longer opens the wallet!

We eliminated this danger by completely changing the BulKey Code Wallet™ mechanism.

Read More: How reliable is the locking mechanism?

We have done the construction of the locking mechanism axial. Unlike other code mechanisms on the market where the code is changed by pressing a button on each wheel individually to change the digit code, with the axial variant we use, only one button that needs to be pressed to set the new code. Thus, the whole mechanism is under the pressure of a strong spring, which does not allow unwanted movement of the code change selectors, even under high dynamic impact.

Also, setting the new code with just one button makes it really easy for the owner of BulKey Code Wallet™ to change the code anytime.

Read More: How to change my code?

Thanks to this axial construction, the locking mechanism has a very compact size, which subsequently helped us to keep the pocket size of BulKey Code Wallet™ and make it more ergonomic and comfortable to use.

  • Our third goal is that the code mechanism is sufficiently secure.

What is the problem on the market? It is related to the aforementioned case of self-change of the code. To avoid customer dissatisfaction with self-changing code, the designers decided to leave visible marks of the correct code. Yes exactly. So that if your code changes itself, you can “see” the new code even with a locked wallet. They’ve even tried to turn the defect into an effect, presenting it as a “secret method to see your code if you’ve forgotten it.” But think about it… If you can recognize what the correct code is, so can thieves. This backdoor is available in many other products on the market. Also, if the code lock is not made precisely, when pressing and turning the code, a slight click is felt and the correct combination can easily be understood.

This is an extremely big security breach that we have not allowed in BulKey Code Wallet™ thanks to the axial mechanism. Our 4-digit code is designed so that it cannot be seen by any means or felt with pressure. If you forget your code, the only way to open the wallet is to destroy it or try 10,000 combinations.

To make sure there are no back doors for opening the wallet, the open button (it also operates the mechanism) is pinned permanently during manufacture and is non-removable. There is no way to get it out without destroying the wallet.

Also, with the help of a channel on the opposite side of the button, we fight against possible forceful attacks on the wallet as the entire force is redistributed through the shells. Thanks to this channel, the cover and the structure retain their integrity even under serious pressure.

Read More: Let’s be realistic…

2. Security steel cord.

The security steel cord is one of the most important innovations in BulKey Code Wallet™. With this cord the wallet can be attached to you (to your bag, to your backpack, to your pants loop, etc.) to prevent pickpockets from stealing your BulKey Code Wallet™ entirely.

We attached the cord directly to the axis of the locking mechanism. Thus, only a person who knows the correct code will be able to detach or attach it. The slit for placing the anchor is made and sized in such a way that the wallet can be unlocked and used without detaching the cord.

We made the “loop” of the cord through which the anchor is threaded, small enough that the owner can thread it even through a zipper.

The cord itself is made of multi-strand stainless steel cable. Covered with PVC coating so that there is no unpleasant touch and it does not scratch clothes and bags. The anchor isn’t just a T-shape, it’s smooth-edged to make it easy to insert into the slit and again feel good to the touch.

At the same time, after long analysis, we have determined the length (38cm/15 inch) so that it is not too long to bother, but at the same time allows the easy handling of BulKey Code Wallet™ even when it is attached to it.

Read More: When and how to use the secuity steel cord?

3. First prototypes and construction

Now that we had the locking mechanism and cord figured out, we needed to make a working prototype to test them with. The first prototypes was quite jagged and non-ergonomic, but it served its purpose to test the functionality of the wallet.

The next step was to clean up individual design elements and assemble them into a final product form that looks great and feels very comfortable in the hand.

The first thing we improved was the hinge. On the first prototype it protrudes from the wallet’s body.

Therefore, the idea of ​​the new hinge was to be completely hidden in the case, but still allow 180-degree opening of the lid. Thus, placing and searching for valuables ​​will be much easier. Also, the wallet will be able to stay open on a flat surface without tipping over.

From a constructive point of view, the hinges are made in such a way that once they assembled during production, it is impossible to pull them out. The end result, as you can see, is an extremely elegant and minimalistic design that covers all our goals.

Our next task was to sculpt the case of the wallet to be comfortable without reducing the internal volume. At this stage we used our 3D printers to try out all the options we had made and choose the one that was most comfortable to use.

See also: What can i store in BulKey Code Wallet?

This was a very important part, because in design systems there is no way to feel the final product and make it with the exact ergonomics that we want. This is how the small bevel before the opening button was designed, which greatly contributes to the pleasant feeling when you open your purse.

Since the wallet is practically a personal safe, we decided to add a design with an embossed safe on the lid, and even the hinges of the design match the actual hinges.

During these tests, we added pins in the housing and an additional third locking tooth to strengthen the construction and eliminate bending as much as possible.

4. Polycarbonate

Now that we had a fully working prototype, it was time to find the material that would make the final products.

Already with the first prototypes, we tested how they themselves behaved when made of different polymers. We focused on these materials because they allow optimal design freedom and easy production, resulting in an affordable price for our end customers.

Thus, from all the we tests made, polycarbonate turned out to be the most optimal solution for our needs, because it is sufficiently strong, tough and elastic. If it was too strong, it would break when hit with a hammer, and if it was too flexible when dropped, the wallet would open too easily.

Read More: How impact resistant is BulKey Code Wallet?

Although significantly more expensive than other polymers, polycarbonate meets our requirements perfectly. It is also non-flammable and very difficult to melt.All these features make it an ideal choice for everyday use.

The axis on which the locking mechanism and teeth are located as well as the plate in which the teeth themselves are locking, are produced from glass-filled polycarbonate. Therefore, they are a very strong and rigid component and create great resistance to a potential forceful attack.

5. Tracking, RFID protection and aluminum case

As already mentioned, from the beginning we wanted the wallet to have an electronic lock and built-in Bluetooth tracking. But after analysis, we realized that this would take away from the wallet space. In addition, tracking will not be necessary for everyone, and it would make the product more expensive. 

There are more and more Bluetooth tracking devices on the market with more and more features, so the task remained for us to make the wallet compatible with these trackers and for each user to decide for himself which tracking device to use. Unfortunately for us, this task is in direct conflict with another goal of ours: to make the wallet RFID-protected and the contactless bank cards in it secure. 

We looked at an option to cover the wallet in aluminum like other products on the market. This would solve the RFID protection issue, but destroy compatibility with tracking devices. We had to make a serious comparison of the two tasks and see which one will be more useful.

You can read more about the analysis here: RFID protection and aluminium case

We decided to make the BulKey Code Wallet™ compatible with Bluetooth trackers because they would be much more applicable when using the wallet. RFID protection is largely a marketing trick and will unnecessarily make the product more expensive. However, if you want RFID protection, for 50 cents you can buy a card sleeve like the one in the picture and your problem will be solved.

In the future, we also plan to produce a series with an aluminum cover for fans of aluminum wallets. Stay tuned!

See more: How can I track my BulKey Code Wallet?

6. Organizer.

The original design of the wallet was to be a box in which to put banknotes and cards. With this design, the wallet could hold up to 80 bills. But in the process of testing, we found that in order to conveniently store and find the banknotes easily, we need to have an organizer.

So, we had to design and cut a special polypropylene organizer to make 6 pockets in which to put your items when opening the wallet. And so, the wallet became with its current volume of 40 bills. And its size remained such that it is still possible to place a car key, money and a cards inside.

7. Environmentally friendly

Since one of our goals is to preserve nature and have a minimal negative impact on it, we have made an effort to make it so.

We have almost no waste in the production process. We made sure that the wallet has no embedded (cast) metal parts, with the only metal components being the two hinge pins, the two springs and six small screws, which before recycling can be removed and even those can be recycled. The rest of the parts are made of polycarbonate, which is a polymer subject to repeated recycling. Thus, BulKey Code Wallet™ is 100% recyclable.

We have also paid close attention to the packaging in which BulKey Code Wallet™ arrives.

Our product box is entirely cardboard and printed with UV inks making it fully recyclable, unlike typical glossy boxes that are covered with a thin film of plastic. This thin film is the obstacle to them being recycled again.

Only the inner packaging turned out to be a problem. The product cannot be placed directly in its sales box due to the risk of scratches during transport before it reaches the customer. Therefore, a plastic bag is typically used, which at the moment of opening the product is simply thrown away. Also, these plastic bags are often too thin and cannot be recycled.

Our solution to this is to provide you with BulKey Code Wallet™ in a stylish black velvet bag which can then be used to store your wallet or other items.

8. Production

So, after finalizing the last detail, we had to organize the production. Of course, thanks to our many years of experience in developing new products, the details of the wallet were considered already in the design to be technologically possible for mass production. Naturally, for such an innovative product on the market, we will have to design and manufacture special machines and robots for the production of certain details from BulKey Code Wallet™. This is the only way we can achieve an affordable final price of the BulKey Code Wallet™, despite the complex construction and many innovative details.

For the polycarbonate details, we have developed specialized molds to cast them using our robotic injection molding machines. Due to the special design of the wheels with the numbers (reliability and security of the code mechanism), we had to make a special automatic machine for printing them. We also designed and built our own machines and robots for the production of the protective steel cord to automate the laborious and slow process of crimping (clamping) the anchor and making the “loop”. Finally, we made robots to help assemble the wallet itself.

Read More: How strong is the security steel cord?

Let's see the requirements again:

  • To have a 4-digit code – done
  • The code is sufficiently protected – done
  • The code cannot be moved by itself – done
  • Pocket size – done
  • To have room for over 80 banknotes- they are reduced to 40 because of the organizer, but if you want that space, you can remove the organizer completely and use the full capacity of the wallet.
  • Have room for keys – yes, even with the BulKey Code Wallet™ organizer there is room for keys.
  • To have built-in Bluetooth tracking – We have left room for the client to decide for himself whether he wants to put a tracker, and if so, to choose the brand and type of tracker himself.
  • To have RFID protection – there is none, but the customer can easily put a protective case.
  • Ability to attach to different places – done
  • To have affordable price – done

9. The testing

Of course, during the designing process we constantly tested the BulKey Code Wallet™. First, we started with the prototypes and their functionalities. We then continued with a crash test where we hit the wallet with a hammer, ran over it with a car, dropped it from the second floor and more.

After it passed the crash test, we tested it for its durability. We gave away a few wallets to other travelers so they could test them out. Even before the sales started, BulKey Code Wallet™ toured the globe. There were wallets sent to East Asia (Cambodia, Laos, Sri Lanka), Africa (Egypt, Zanzibar, Tunisia, Morocco), Europe (Spain, Germany, Romania, Greece, Estonia, France, Czech Republic, Italy, Cyprus and others ) North America (Mexico, USA) South America (Brazil) and in Australia and New Zealand.

All reviews and impressions were great! And that was the last sign we were waiting for!

And here our story about how we designed it, ends…

… and your journey begins!

get your
wallet now!

enjoy the moment without
worrying about pickpockets

Shopping Cart