How was the Hunter Board designed and built?
Welcome to the "Build Guide" of the Hunter Board. Thank you for being curious about what we've been cooking for some time at Hunter. When you scroll down, you're going to find the answer to hundreds of design/build-related questions, which we hope will answer any doubt you might have about the Hunter Board.
What you'll have discovered at the end of this build guide:
- Our design goals with the Hunter Board;
- The rationale behind every decision we made while designing and building the Hunter Board;
- Why a Suspension System and how we made it.
Any doubt you might have, please let us know.
Top Speed 50 kph (31 mph)
Range 38 km (24 miles)
Agile Turning System
7075-T6 Premium Space-Grade Aluminum
3600 Watt Direct Drive Motor
Weight 9 kg (19 lbs)
- VESC 6.6
Easily Swappable Battery
30% Hill Climbing
Designed and Built in Europe
First of all, why are we telling you our "secrets"?
At Hunter, we believe that to bake the fabulous cake called Trust, we need the key ingredient called Transparency. Transparency can only be achieved by exposing the naked, hard truth.
Why is the Hunter Board made of aluminum? How did we build our Suspension System? There are hundreds of questions that can and have been answered. It took us three years and thousands of hours to ideate, develop, prototype, test, and start producing the Hunter Board. It would be a shame if we didn't have enough confidence in our product to show you everything.
Magic is just Science waiting to be explained.
What were our goals while designing the Hunter Board?
To effectively design a product, we have to define a set of objectives to pursue. Below you can find the main design goals we set out to accomplish and why.
Build a light electric skateboard with an integrated suspension system.
To reduce your risk of falling and keep you going forward, faster, no matter how rough the road ahead is. What's the point of having a powerful vehicle, if we don't feel safe and comfortable riding it? A suspension system's job is to absorb the vibrations from the road. These vibrations can come from holes, debris, potholes, and everything on your way. By integrating a suspension system, specifically built for electric skateboards, into the Hunter Board, we can significantly reduce the amount of vibration and bumps your feet feel. The result is a reduced danger of falling. If you don't fall, you can go further, and faster.
Maybe you're saying to yourself: "A flexible deck also absorbs vibrations". That's true, but on a much smaller scale when compared to a suspension system. With a suspension system on a rigid deck, it also becomes possible to have shock absorption with and the superior handling characteristics of rigid decks.
Make an electric skateboard as light as possible, while not compromising on performance.
The Hunter Board is a commute-ready personal electric vehicle. For an efficient and happy commute, you need a vehicle with range, speed, comfort (suspension system), and light enough to be easy to carry around. The challenge in this lies in the fact that it's extremely tough to build an electric skateboard with a fantastic range, outstanding speed, and lightweight, all at the same time. Extra range and speed mostly come down to more batteries, and this only makes the electric skateboard heavier.
The key to solving this problem was in making the Hunter Board in aluminum. You can learn more about how we did it and why did we choose aluminum over carbon fiber and wood in the "Deck" and "Aluminum" sections below.
Build a versatile e-board, agile at slow speeds, and stable at high velocities.
Versatility matters. Sometimes we might want to carve into the sunset, and for that, we need agility. Other times we want to be a speed demon. For that, we need stability. Unfortunately, regular boards can't be agile and stable at the same time. Choosing one requires sacrificing the other. This means that the perfect board for carving is too unstable for high speeds, and the ideal board to cruise at 30 miles per hour isn't agile enough for a good carving session by the sea.
We felt this was a severe handicap and set out to develop technology that allowed us to build a more versatile board: one where outstanding agility meets unwavering stability.
The user should be able to swap the battery pack easily.
Quickly swappable battery packs come with several advantages:
- If you run out of battery, replace the battery pack, and you're good to go. You can cross an entire continent on your Hunter Board without stopping to charge as long as you carry enough replacement batteries;
- If you're having problems with your battery, no need to send the whole board back to us for repairs, all you have to do is replace the battery pack, and you're good to go;
- If you want to do some airplane traveling and can't take the battery with you, leave it at home, and we'll hook you up with a battery at your destination. This service is called Rent the Power, and we'll release more information about it soon.
The Hunter Board is the result of the pursuit of these goals. Since form follows performance, the Hunter Board's design was conceptualized and brought to life, taking into account the fulfillment of the objectives above and the prospect of superior experience in all fields, from handling to comfort.
Below you can find an extensive description of the rationale behind our decisions when building the Hunter Board. A functioning mechanical product is the result of a delicate balance between the laws of physics and all its parts. After reading everything, you'll be able to understand our decisions and the thinking behind them.
At Hunter, excellent performance isn't enough. For an e-board to be considered vehicle grade, it needs to be comfortable to ride at high and low speeds. It's all about going fast and far, no matter how rough the road is. For this, we need a working suspension system to absorb bumps and vibrations. The less shock you receive, the more stable you are, and the less you fall. The less you fall, the faster and further you go.
Existing e-boards with suspension systems follow the example of cars, where a fixed plane under the deck and parallel to the ground is required to keep it from affecting the turning system. This isn't optimal because of the resulting heavyweight.
To build a light e-board with a suspension system, we had to rethink how skateboards are made, by overcoming two challenges:
- Build a suspension system with no fixed plane under the deck;
- Build a suspension system fully independent from the turning system.
After developing over 75 prototypes and testing several solutions, the key to solving these challenges was in fixing most of the turning and suspension system to the central axis of the Hunter Board's deck. The suspension system springs are customizable and can be adapted to the rider's weight.
We submitted a patent for our suspension system in July 2020. Below you can see some of the drawings we made for the patent submission.
Agile Turning System
As said above, one of our objectives with the Hunter Board was to build a more versatile board with excellent agility at low speeds and outstanding stability at high speeds. The key to doing this was developing a more agile mechanical turning system that could coexist with the Hunter Board's suspension system and the superior stability which comes with it.
There are two rods connected with an offset to the center of the deck. These two rods connect directly to the wheel. When you rotate the deck, these rods push one wheel and pull the opposite wheel. To keep the suspension system separate from the steering system, we connected the suspension system to the pivot point on the deck to turn freely.
To make sure your Hunter Board is agile enough, we built a mechanical turning system with a 25º turning angle. It might not sound like much, but with a 25º turning angle, you can do a full circle in a one-lane road. This means that you're able to have all the agility you need for your carving session.
The coexistence of the mechanical turning system with the suspension system gives the Hunter Board agility when you need to carve and stability when you need to go fast, or the road gets rougher.
To build the Hunter Board's a 1.9 kg 333-Wh lithium-ion battery, we used LG HG2 cells (10s3p configuration). The team chose to use these batteries thanks to its reliability in the long term.
The battery pack is easily swappable, so if you run out of battery and have no place to charge it, replace the battery, and you're ready to go.
The Hunter Board wheels are custom made for Hunter in Portugal by one of our partner companies. Being so close to the production center of such a critical part gives us the ability to customize every detail as we see fit. This reflects in the wheels' horizontal tears. These tears' objective is to increase water runoff and traction on uneven floors.
The wheel comes with aluminum rims to help dissipate the heat produced by the motors. The rims are, like the deck, trucks, and many other parts, made by Hunter in its factory in Portugal.
Below you can see a computer-generated picture of the Hunter Board's wheel.
At Hunter, we use 7075-T6 Aerospace Grade Premium Aluminum to build the Hunter Board. Aluminum is probably the best material available to produce a high performing electric skateboard. It has a level of mechanical strength very close to some of the best steel and titanium alloys despite only having half of the titanium's weight and one-third of the weight of steel.
You might be asking yourself: "Why not make the Hunter Board in carbon fiber or wood?". It happens that aluminum is a metal. Like all metals and glass, aluminum has a distinctive characteristic that blows carbon fiber and wood out of the water: Isotropy - uniformity in all orientations.
What does being isotropic mean for materials? It means that physical properties do not vary in different directions. You know what to expect and where to expect. This property allows us to eliminate material where it's needed and build the lightest and best performing vehicle possible.
To know what to shave and what to leave, we did hundreds of intensive tension tests. The attention to detail can be seen on the fact that some parts of the Hunter Board are only 0.5 mm thick. Isn't that too thin you might be asking? No, it's perfect because that's the exact amount of aluminum needed for top performance.
While aluminum is isotropic, wood and carbon fiber are anisotropic. This means the properties of the material are directionally dependent. The strength of wood depends on the orientation of the grain, and the strength of carbon fiber depends on the fiber orientation. We have no way of precisely knowing where to shave material as we do by milling aluminum while knowing how that will affect the overall strength of the object.
But isn't carbon fiber already lighter than aluminum? Yes, it is, but from the moment you can eliminate material in aluminum and not in carbon fiber, you can get a lighter object and more creative freedom to build a better product.
We know that when someone weighing 90 kg (198.4 lbs) is on the Hunter Board, the aluminum deck will flex precisely 4 mm. We would never be able to have this kind of certainty in a wood or carbon fiber deck.
When you look at the Hunter Board, the first thing you notice is the eye-grabbing aerospace-grade premium aluminum from which the deck is made. As explained above in the "Aluminum" section, there are several advantages to use aluminum as a raw material to build an electric skateboard, and this reflects in the deck's weight and format.
Also, from the moment we're able to shave aluminum precisely where we want, we can place all sensible components like batteries and electronics inside the deck where everything's safe and protected. This gives the Hunter Board a super sleek look and makes it a better performing vehicle since there's less air resistance.
In addition to this, you'll notice the deck has a curved shape on the sides. Initially, we designed the Hunter Board to have a flat deck, but we realized it would be more comfortable for the rider to bend the sides upward.
Lightweight + High Performing + Comfortable.
The Hunter Board comes with 3600 Watts of power concentrated in two Direct-Drive/Hub hybrid motors, one in each back wheel. What does this mean? It means that the motors are inside the wheels but never touch it, meaning that they're protected against everything like a hub motor, but have a much bigger heat dissipation area. In the end, we've got a vastly more consistent power delivery and consumption. Get ready for an amazing performance.
When designing the Hunter Board, we were faced with a choice: direct-drive/hub or belt motor. Motors have a direct influence on weight and performance. Since one of the team's goals was to build an electric skateboard as light as possible, while not compromising on performance, we had to carefully analyze how each motor influenced the fulfillment of the objective.
Pros of Direct-Drive/Hub Motors
- More efficient overall - a hub motor can do more miles than a belt motor with the same battery;
- Motors aren't exposed (they're inside the wheel), which leads to less damage;
- No maintenance needed;
- More aesthetically pleasing (team's personal opinion).
Cons of Direct-Drive/Hub Motors
- Less efficient at the initial start;
- The rider feels more the bumps and vibrations of the road since there's less rubber in the wheel than it would be if the motor were located outside the wheel - Hunter's proprietary suspension system solves this problem.You can learn more about this in the Suspension section above;
Pros of Belt Motors
- Less risk of overheating, since the motors are more exposed;
- More efficient at the initial start;
- You can change wheels more easily;
- You can tinker with the transmission.
Cons of Belt Motors
- Superior weight;
- Maintenance needed;
- The need to replace parts as time goes by;
- Motors are more exposed, which leads to more damage;
- Less efficient on the overall - a belt motor does fewer miles than a hub motor with the same battery.
After looking into all these factors, the team decided to go forward with Direct-Drive/Hub motors for their reduced weight and better performance in the long run. We know this decision might be controversial among some ranks of the electric skateboarding community who prefer belt over hub, but we sincerely believe we've made the best choice. If you're still not convinced, the best way to eliminate all doubts is by trying a Hunter Board.
The first thing you'll notice in the Lightsaber Remote is the fact that it looks like, well, a Lightsaber. Entirely made of premium aerospace-grade aluminum (7075-T6), it's cylindrical shape allows us to store bigger capacity batteries inside, giving the remote enough battery for up to 50 full rides.
Why a cylindrical shape? In addition to the additional space for more reliable batteries, the natural ergonomy of cylindrical shape objects guarantees that users won't feel uncomfortable using our remote.
The Lightsaber Remote comes with a small screen where you can see how fast you are going or how much battery you have left. You're also able to change your ride mode or build a custom one. You can create a custom ride mode by customizing your Hunter Board's acceleration and braking curve, max power, braking power, and much more.