Help me design my hoverboard.

[RChovercraft]

Hi everyone,

I am working on making a hoverboard with 360 degree movement handlebar controls and four side fans with 150 degree variable positioning for increased control.

My latest design uses four 4" fans in two carbon fiber ducting to pull air in the front and down to the 16" fans at the bottom for the main lift force.
(the picture below shows the carbon fiber housing and the tubes out the back).

Next four groups of 12 fans will be placed two groups of three on the left and two groups of three of the right side (similar to the placement of tires on a car). In each group one fan will intake air, one fan will push air down and one fan will use one of the four 4-1/2 "carbon fiber tubes to push air out the sides in a variable 150 degrees radius.

For controls I have been thinking of using something similar to scooter controls, but the variable turn controls should provide a completely different and improved ability to move around and in completely new ways.

The controls will have the standard left and right turns found in cars. If you turn left, than the right front and the left back fan would push the air out the sides to turn left, to turn right the front left and back right fan would turn on.

The difference is that the variable 150 degree movement of the side could be controlled by moving the control stick in any 360 degree direction to get a very controlled movement in that direction. You could even move the fans to angle towards the front to act as an air brake. This would be a completely new way of moving from all cars and hoverboards out today.

Here is a quick beginning drawing of my concept.
http://farm4.static.flickr.com/3176/2884632811_07b921bf08_o.jpghttp://farm4.static.flickr.com/3210/2884893667_6ca72b7224_o.jpg

I am going to use materials from a ducted fan attachment I made for my bike shown below. Four 4" ducted fans have been mounted in carbon fiber ducting will be used to intake air for the main 16" lifting fans, while the 4-1/2" tubes will be used on the side fans.
http://farm4.static.flickr.com/3212/2439210277_ce1a0a4ceb.jpg

I would like to use 2 16" Nascar 2700 CFM fans that I have picked up for the main levitation thrust (similar to the diagram of the 16" fan below), I am planning on making a bag & fingered skirt to hold in the air and increase the levitation height (kite material is the best material that I have found thus far).
http://www.okoffroad.com/gifs/stuff/fan-2.jpg



I still have a way to go, but I would appreciate any comments or suggestions you may have.

[metroidrc]

wow..
i have an idea for you
one 120mm fan in the middle of a disk, running on 6s lipo. how much do you weigh? this would determine if it would be able to hover/glide over the surface.

I think maybe overcomplicating it would hurt you. a single fan(maybe two) would be enough to do the job. its going to need to have a skirt I think, or some type of skirt anyway...

[challenger_i]

Surface area is important, too.

[RChovercraft]

wow..
i have an idea for you
one 120mm fan in the middle of a disk, running on 6s lipo. how much do you weigh? this would determine if it would be able to hover/glide over the surface.

I think maybe overcomplicating it would hurt you. a single fan(maybe two) would be enough to do the job. its going to need to have a skirt I think, or some type of skirt anyway...

Hey Metroid,

Thanks for the response! I just don't think that one 120mm fan would do the trick.

I know that more fans will add more weight, but nearly all of these extra fans will add to the lifting force.

I have four 4 " fans in the carbon fiber ducting shown in the picture on the table above that will draw air down to the 16" fans below. These 4" fans are made for boats or very large car intake systems. They are made out of ABS plastic, but they have been sanded down to reduce weight. I have used these fans before as an attachment on my carbon fiber road bike to gain speed, and they worked! I would get a boost of speed that would help most on straight ways and small hills.

The 16" fans are rated at about 2500 CFM, and I have also planned on having four smaller ducted fans on each corner of the board where the side fans would be located pushing air down.

This would mean I would have 8 intake fans, 2 large 16" fans, and 4 smaller fans adding to the lifting height.I will also be making a bag and fingered skirt once I figure out the material that I want to use.


I have been thinking of adding a customized motor that would use less energy, and even recapture energy while the motor is moving. I would use this motor on the 2 large 16" fans and the four smaller fans that would be pushing air down to gain lifting height.

http://farm4.static.flickr.com/3165/2889661791_3b88bf4c48_o.jpg

[metroidrc]

the reason I think a 120mm fan would do the trick - is that I have a leaf blower powered hovercraft that can lift my own weight, and doesn't provide even 1/4 of the thrust that a 120mm fan with a brushless motor would. You might want to look into it - at least as an option. Having so many fans could generate problems... I try to keep it as simple as possible. I am very anxious to see what you come up with though! Thanks for posting this.

[RChovercraft]

the reason I think a 120mm fan would do the trick - is that I have a leaf blower powered hovercraft that can lift my own weight, and doesn't provide even 1/4 of the thrust that a 120mm fan with a brushless motor would.

My design would use four 120mm fans just for the corner downward fans.

I wanted to stay away from leaf blowers because of the noise involved. I am going to be using dynamat car sound dampening material and another light sound dampening material that I picked up, but I still expect noise to be a major problem.

You might want to look into it - at least as an option. Having so many fans could generate problems... I try to keep it as simple as possible. I am very anxious to see what you come up with though! Thanks for posting this.

You are absolutely right that it will be very hard to power and manage all of these fans, but I think they will be very essential in adding maneuvering capability and lift height.

[metroidrc]

even four 120mm fan units wouldn't lift a person up, but one would have enough for it to be hovercraft style up. with one 120mm fan you could get say 10 - 15 lbs of thrust. Add 150 - 250 lb person and some batteries, theres no way thats gonna make you get off the ground.... is this gona be more hovercraft style or levitating?

[RChovercraft]

Surface area is important, too.

It is, I expect my design to measure approximately 2 1/2 feet by an approximately 4 1/2 feet.

I want to stay away from the circular concepts because it has a larger profile and my concept should be MUCH easier to control.

[RChovercraft]

even four 120mm fan units wouldn't lift a person up, but one would have enough for it to be hovercraft style up. with one 120mm fan you could get say 10 - 15 lbs of thrust. Add 150 - 250 lb person and some batteries, theres no way thats gonna make you get off the ground.... is this gona be more hovercraft style or levitating?

Levitating? No, I am making a small personal hovercraft with side fans for increased maneuvering.

Four small 120mm fans, and two 16" fans with 8 fans intaking air for them HOPEFULLY should be enough to get a few inches off the ground.

[RChovercraft]

A few things I still have not figured out.

1) I do not know what I should use as my main propulsion on the back. I have been thinking of two very large ducted fans, but I have not figured out what size.

2) I will need to program in controls for the scooter control stick that will move the side fans as the scooter control stick is moved in any 360 degree direction. I am hopefully going to get some electronic and programming help for this.

3) I do not know what skirt material to use. I want it to be durable but light.

[metroidrc]

Its not going to get a few inches off the ground. You would need a small nuclear engine to pull that off, or a big prop at the top like a helicopter. most it will get is maybe half an inch with someone standing on it. I dunno if it could even get that high. Prove me wrong though! :)

[RChovercraft]

Its not going to get a few inches off the ground. You would need a small nuclear engine to pull that off, or a big prop at the top like a helicopter. most it will get is maybe half an inch with someone standing on it. I dunno if it could even get that high. Prove me wrong though! :)

A small nuclear engine!!! A leaf blower or two could easily get this off the ground, and that's much less than a nuclear engine!

It is hard to measure the benefit from the intake fans until I try it. If it works than I will move on from there. If it needs more power than I will add more.

I have about 3 weeks until I start to get the rest of my materials. Until than I will work on my design, draw the concept up in AutoCAD, do the mathematic calculations, and figure out what exactly I will need to buy.

I will also work on talking to my friends about getting their help programming the scooter controls which will be one of the hardest tasks of the project.

[RChovercraft]

I will also be working on the regenerative motor that I have drawn below. These will also work as a suspension system and any movement will also generate energy and act similarly to a kinetic energy watch that generates energy from the movement of the watch.


http://farm4.static.flickr.com/3165/2889661791_3b88bf4c48_o.jpg

[metroidrc]

A small nuclear engine!!! A leaf blower or two could easily get this off the ground, and that's much less than a nuclear engine!

It is hard to measure the benefit from the intake fans until I try it. If it works than I will move on from there. If it needs more power than I will add more.

I have about 3 weeks until I start to get the rest of my materials. Until than I will work on my design, draw the concept up in AutoCAD, do the mathematic calculations, and figure out what exactly I will need to buy.

I will also work on talking to my friends about getting their help programming the scooter controls which will be one of the hardest tasks of the project.

leaf blowers won't hover it off the ground more than 1/4"...

[RChovercraft]

leaf blowers won't hover it off the ground more than 1/4"...

The most powerfull Leaf blowers have about 300-400 CFM. Just one of the 16 4" fans that I will be using has that much output, and my two 16" fans put out 2500 CFM each before the boost from the intake fans.

I really think that my model has enough force to get at least partially off the ground, and if it needs more than I will add it.


Getting off the ground is not my main concern though. Programming in the scooter controls to control the side fans will be the hardest part of the project. I also need to figure out what I am going to use for my main propulsion system.

[metroidrc]

well I wish you the best of luck with it, and I will be watching closely, thats for sure! :)

[RChovercraft]

well I wish you the best of luck with it, and I will be watching closely, thats for sure! :)
Thanks Metroid, I appreciate your input.

I will post more as I get farther in my design.

Right now the major aspect that I have not figured out is the main propulsion system.

I have thought about using two small pulse jets, two large ducted fans, or an internal maglev propulsion system I recently thought of.

[RChovercraft]

I am working on setting up my electrical system.

I will have two fans drawing 12.5 amps each, twelve fans drawing 2.5 amps each, and four fans that will use my maglev regenerative motor which might produce energy.

I have 12V 75AH of battery power now that I will use for testing the concept, but I might get a 12V Lithium Iron Phoshate battery pack with 110AH of battery life, which would provide about 3.3 hours of use if I use all of my battery packs together.

I think that I will be getting my batteries from a supplier from China to reduce costs.

Here's some information about Lithium Iron Phosphate batteries:

up to 500 degrees CelsiusLife cycle: 2000. Non-toxic, non-contaminating, contains no rare metalWith UL, CE, SGS/RoHS approval. Working temperature range: -20 to +70 degrees CelsiusFlexible form factor: small in size and light in weight, 1/3 weight of lead acid and 65% weight of NiMh battery

[RChovercraft]

Magnetic Suspension can this make lifting a lot easier?

I have been thinking of using permanent magnets to separate the top area of my hoverboard with my batteries from the bottom area with the lifting fans. Would this make lifting easier?

[metroidrc]

why do they need to be seperated?

[RChovercraft]

why do they need to be seperated?

I had this idea a few years ago and have been thinking and working on it ever since, but I still don't know if it will work.

The idea is that a permanent magnet in a half spherical ball could repel a permanent magnet with a larger shell that would repel the two magnets with a much larger force than two flat magnets, and it would also keep the system in place.

http://upload.wikimedia.org/wikipedia/commons/thumb/8/84/Shell-diag-4.png/312px-Shell-diag-4.png
The idea is that a permanent magnet in a half spherical ball could repel a permanent magnet with a larger shell that would repel the two magnets with a much larger force than two flat magnets, and it would also keep the system in place.

If there were dampeners under these magnetic suspension points, than the idea is that it would be easier to push the hovercraft up because the magnets would lift the heavy battery and standing section while the fans would only have to lift the base.

Here is an electromagnetic suspension system for cars from Bose. My system would use permanent magnets that would not require energy to run.

Bose Suspension System (http://www.youtube.com/watch?v=eSi6J-QK1lw)

[metroidrc]

wow thats really interesting! thanks for the video!

[mohillbilly]

I was impressed till the end. Thats fake as hell.

[RChovercraft]

I was impressed till the end. Thats fake as hell.

The whole video is real.

http://www.nytimes.com/2004/10/11/automobiles/11CARS.html?pagewanted=all&position=
A New Suspension's Magnetic Appeal
By TIM MORAN

Published: October 11, 2004


The Bose suspension uses "linear motors" that contain powerful magnets and high-voltage electrical coils.

This summer, at its headquarters in Framingham, Mass., Bose showed off its work in progress. Journalists who attended the demonstration said they saw a 1994 Lexus LS 400 sedan equipped with the company's electromagnetic suspension negotiate bumps and potholes with the mastery of a professional skier attacking a run full of moguls, legs flexing at the knee but head remaining level and nearly motionless. They even saw the luxury sedan pop its front wheels into the air at a standstill.


http://www.bose.com/controller?event=VIEW_STATIC_PAGE_EVENT&url=/learning/project_sound/suspension_components.jsp

The Bose® suspension system includes a linear electromagnetic motor and power amplifier at each wheel, and a set of control algorithms. This proprietary combination of suspension hardware and control software makes it possible, for the first time, to combine superior comfort and superior control in the same vehicle.

Linear electromagnetic motor
A linear electromagnetic motor is installed at each wheel of a Bose equipped vehicle. Inside the linear electromagnetic motor are magnets and coils of wire. When electrical power is applied to the coils, the motor retracts and extends, creating motion between the wheel and car body.

One of the key advantages of an electromagnetic approach is speed. The linear electromagnetic motor responds quickly enough to counter the effects of bumps and potholes, maintaining a comfortable ride. Additionally, the motor has been designed for maximum strength in a small package, allowing it to put out enough force to prevent the car from rolling and pitching during aggressive driving maneuvers.

Power amplifier
The power amplifier delivers electrical power to the motor in response to signals from the control algorithms. The amplifiers are based on switching amplification technologies pioneered by Dr. Bose at MIT in the early 1960s — technologies that led to the founding of Bose Corporation in 1964.

The regenerative power amplifiers allow power to flow into the linear electromagnetic motor and also allow power to be returned from the motor. For example, when the Bose suspension encounters a pothole, power is used to extend the motor and isolate the vehicle's occupants from the disturbance. On the far side of the pothole, the motor operates as a generator and returns power back through the amplifier. In so doing, the Bose suspension requires less than a third of the power of a typical vehicle's air conditioner system.

Control algorithms
The Bose suspension system is controlled by a set of mathematical algorithms developed over the 24 years of research. These control algorithms operate by observing sensor measurements taken from around the car and sending commands to the power amplifiers installed in each corner of the vehicle. The goal of the control algorithms is to allow the car to glide smoothly over roads and to eliminate roll and pitch during driving.

http://www.bose.com/images/learning/lc_suspen_motor_lrg.jpg


Bose linear
electromagnetic motor
The Bose linear electromagnetic motor offers easy two-point mounting. The only electrical connections to the motor are for power and control.

http://www.bose.com/images/learning/lc_suspen_system.jpg



A linear electromagnetic motor is installed at each wheel of a Bose equipped vehicle. The control algorithms operate by observing sensor measurements taken from around the car and sending commands to the motors.



http://www.bose.com/images/learning/lc_suspen_frt_mod.jpg

Bose suspension
front corner module
The Bose suspension front corner module features simple strut and link construction.

The linear electromagnetic motor is used as a telescoping suspension strut along with a two-piece lower control arm. A torsion bar spring connected to one end of the lower arm supports the weight of the vehicle. The wheel damper keeps the tire from bouncing and losing contact with the road.

[RChovercraft]

The main problem with the Bose suspension system is that it required energy to operate.

I have been thinking of making a system with permanent magnets that would not require energy to operate. THE KEY about my system is to use an ice cream cone shaped magnet with the top pushing up, and the bottom would be pushing against a cone shaped array of Halbach arrays which focuses magnetic energy to push up and to the side.


Halbach arrays are a placement of magnets in a 90 degree varying arraignment -shown below- which allows magnetic energy to be focused without using electromagnets.
http://upload.wikimedia.org/wikipedia/commons/thumb/a/a7/Halbach_array.png/120px-Halbach_array.png

Because every action has an equal and opposite reaction, the cone area of the ice cream cone shaped magnet would use the half spherical section to push up in a much more powerful and controlled way than the force of two flat magnets repelling each other. The bottom of the cone area of the magnets would push down against a cone shaped magnet with Halbach arrays. This will allow the system to push up at the top, and down and out at the bottom to redirect a significant amount of the energy outwards (this energy can be recaptured and turned into electricity as well).

The question is whether separating the heavy top section of my hovercraft from the bottom section by multiple magnetic suspension points would allow the lift fans to lift the craft easier???

[hew565]

I would so "No".
If one magnet is pushing against another, or a coil of wire, then one has to be on the ground in order to lift a hoverboard. Then you can't move the board or you will leave 1/2 of the device behind, and then... no lift. In the car, one half of the magnetic device is attached to the lower suspension that is always in contact with the ground, and the other takes the place of a spring to keep the body floating on the lower suspension. But the entire weight of the car still rests on the tires. On your hovercraft you would be adding total weight without increasing lift.

On a hovercraft, it is not the total CFM of air that a fan will move, but the pressure that it will build under the platform, that lifts it. The more sqft of platform, the more the lift will be. {Lbs/ft2} Make the Lbs less or the pressure more.

[RChovercraft]

I would so "No".
If one magnet is pushing against another, or a coil of wire, then one has to be on the ground in order to lift a hoverboard. Then you can't move the board or you will leave 1/2 of the device behind, and then... no lift. In the car, one half of the magnetic device is attached to the lower suspension that is always in contact with the ground, and the other takes the place of a spring to keep the body floating on the lower suspension. But the entire weight of the car still rests on the tires. On your hovercraft you would be adding total weight without increasing lift.
My suspension device would be placed on the axial of a car, or in the middle structure of a hovercraft, so the magnets would not need to be connected to the ground. They would separate the heavy top section from the bottom section by a magnetically levitated suspension system.

On a hovercraft, it is not the total CFM of air that a fan will move, but the pressure that it will build under the platform, that lifts it. The more sqft of platform, the more the lift will be. {Lbs/ft2} Make the Lbs less or the pressure more.
Thank you for the response! This is exactly what I am trying to figure out.

The question is if whether {lbs/sq. ft} will still be the same if the bottom section of the hovercraft is seprated from the top part of the hovercraft by a magnetic suspension device. the key to my plan is that the shape of the magnetic suspension device allows energy at the top to push up and keep the unit in place on the sides, while the lower cone section would use Halbach arrays to redirect much of the force outwards.

The bottom cone section could even turn the halbach arrays and generate energy just by the weight pressure of the vehicle.

[jpeca]

RCHovercraft

Not sure if this was covered, but here is how I see it.

If the craft is 2.5 X 4.5 feet, that is 1,620 sq-in's. In order to lift 150 pounds, the fans must be capable of producing 0.0925 psi. In addition to lifting 150 pounds, there must be enough CFM to sustain lift.

[RChovercraft]

RCHovercraft

Not sure if this was covered, but here is how I see it.

If the craft is 2.5 X 4.5 feet, that is 1,620 sq-in's. In order to lift 150 pounds, the fans must be capable of producing 0.0925 psi. In addition to lifting 150 pounds, there must be enough CFM to sustain lift.
How much CFM of fan power would be needed to produce 0.0925 PSI??

[bwalt822]

Your magnet idea to lift up the batteries wont work. Its all an internal force as far as the system is concerned. Magnet which is mounted to the hovercraft will lift the batteries but then what lifts the magnet?

The car video is real. But the wheels lift the magnet which lifts the other half of the magnet which lifts the car. You are replacing the wheels with air pressure. This air pressure is generated by your hovercraft. Magnets are heavy which means more air pressure is needed to lift them.

I also dont see how any kind of "maglev" regeneration would be useful to a hovercraft. Capturing more energy from a motor powered by an internal energy source is a complete waste and is known as a perpetual motion machine. Regeneration is only useful when the kinetic energy of the hovercraft would be regenerated into electricty. The only way to do this is to use the fans to backdrive the motors while coasting. This is very inefficient and wont result in much energy gain. Regeneration is useful on cars because a wheel and transmission is much more effient at transferring energy than what is essentially a wind turbine.

You mention being worried about noise and then mention pulse jets, the loudest form of RC propulsion?

Its great that you are interested in physics but your best bet on getting a hovercraft to work is to search craigslist for old cheap electric leaf blowers. Use two for the lift and then another few for thrust. I doubt that the actual motors in the leaf blowers run off of 120 volt power, they probably are converted down to something that a few 12V batteries could power. I believe leaf blowers use a centrifugal compressor/fan to generate their flow. Centrifugal compressors are much more powerful than conventional fans. Conventional fans are built for high volume and low pressure and hovercrafts need high pressure.

Do a google search for home made hovercrafts too.