The Beamboarder

For hitting the new requirements of the Hackaday price here a new feature for the Beamboarder and for all the other headlights out in this world. 

Running the high Power LED with DC will only be possible when you hit the forward voltage of 9V of the LED Array.  A  11.1 V Li-Po Battery like this one would be perfect from the capacity but the light output and heat would be much to high:

Thats why I want to use a PWM dimm circuit. In this combination the runtime would also be increased to mulitple hours and the output can be controlled by a small microcontroller. The PWM curcuit can also be used for Data Transfer. A fixed frequency modulated with PWM on the light output can be measured by other road user with a little fotodiode. This would be a very simple way for communication between multiple road users with just one message:

I'am also on this road! Please dont hit me!

This technique could also be used for bicycles and other vehicles that are difficult to see at night on the road. The high amount of light created by the Beamboarder should be able to measure from different angles of the Photodiode.

The measurment of the LED Temperature and the creation of the PWM signal can be done by a very small µC like this one:

http://www.cuteminds.com/index.php/en/electronics/picmicro/picprorudiments/115-12f683

Here a paper I found that discibes the light communicaton more in detail:

http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-20-9-10170

For future designs I did some CAD construction that fits to a longboard kingpin. The magnet will be stopped from rotating and hold your optic in the position you want it. You will find lots of round neodym magnets in the internet or in hard disc drives but try to find a thick one that will keep enough force to the kingpin. The surface the lamp sticks to the iron should be as huge as possible. The nut on the backside will keep a lamp at his place and reduce the LED temperature. All joins are done with Arctic Alumina Thermal Adhesiv. The optic is still under construction. By changing the shape of the space blanket the reflection of the light can be controlled in a way, so that other road users will not get blinde. I will show this in detail in some future steps.

Here the CAD Data:

https://grabcad.com/library/beamboarder-v1-1

When I ordered the Cree LED with 9V forward voltage I calculated a runtime of about 4 hours. I couldn’t check the actual voltages of the 9V block lithium ion batteries and ordered multiples with 680 mAh. Actually this kind of batteries will not have the 9 V :/ . Fully charged they have only 8.4 V. This is much too low for this array. The LEDs will only glow a little bit but for a very long time. The NiMH can help with a higher voltage of about 9.6V. The larges battery I could found was with 270 mAh. This gives you 1 hour of high lighting and one hour medium lighting. So what we will need is an LED array with a lower forward voltage. I checked and found this:

http://www.digikey.de/product-detail/de/NT-42D0-0426/521-1039-6-ND/1154195

This type of array fits with 7.6 V forward voltage but the efficiency is much lower than with the Cree. It doubles your capacity and halves the efficiency. Sound wired but that’s what I’m expecting with the the Lamina LED and the 8.4 Li-ion batteries.

http://www.dx.com/p/mp-rechargeable-680mah-9v-6f22-li-ion-battery-for-microphone-remote-control-more-silver-183353

Will this work as Beamboarder?!

With another LED and a 9V 400 mA mains adapter you can build a simple but efficient room light out of the hard disc drive case. The reflection inside the mirror discs creates really amazing shadows from my point of view :) . Check inside the details for how you can build this by yourself.

Now that I realized that the smallest Version of the Beamboarder is ideal for skating around here some more pictures. Use some adhesive between the magnets to increase the heat transfer :

An small package of high power light. In the details you will find more informations about the how to build your own optic.

The material you will need for crafting the battery pack:

You can shrink all together with a lighter:

The voltage will stay at arround 9V and gently drop down. This is the perfect voltage for your LED.

We made several longtime tests  in the last days on the Vennbahn next to Aachen to test the new optic with the space blanket. The results are really amazing. The optic is now ideal for mounting it on the kingpin of your trucks. Much less of the light is swallowed and other road users are not dazzled. On MelloMas’s board we found a way to fixture the battery without an additional plate:

The best experiences we made with the Lichtbohne design. It’s the the savest, lightest und simplest way to get lighting on your board. It was impossible to lose the lamp or the battery without really hard impact. On the kingpin the temperature kept in an acceptable range:

You can also see the slugs we meet on the road still on the board :).

We also tried to film the Beamboarder in action. This was really a challenge in darkness but we found a way to create acceptable footage. The video will follow soon. Try to stay informed.

• Create a night trip video with just the Beamboarder as light source. We will make a little night trip on the vennbahn from the border Germany/Belgien to Aachen

• Better night pictures

• Optimization of the optic.

• Organization of the Night Boarder Event in AC at the end of summer when the nights are longer

• Instructables.com entry

Everybody who likes to join me can do this.

• Do not look directly into the LED from a near distance!
• Do not give the lamp to children!
• Do not turn on the lamp without a proper metal underground for heat transfer. The lamp itself can get to warm driven by a fully charged battery.
• Heating of the battery will decrease efficiency and can damage your battery. Do not mount the warm magnets directly to the battery without isolation.
• With a full battery and a very small plate the LED can get very hot and you will burn your fingers!
• Strong hits or vibrations to your board can cause the battery or the lamp to fall off. Try to increase your magnetic force by direct magnetic contact on a maximum surface area. Place the magnet on the kingpin and use the stumps to avoid rotation. Fixture your battery with one magnet on the battery and on under the longboard. The magnetic setup will properly not hold in all downhill or freestyle actions. You can also tie the battery with an additional binder and mount the LED directly on the trucks. This should survive most actions J.
• The middle of the beam should point in front of you on the ground. Use a proper optic on your lamp to avoid dazzle of other road users.
• Remove the lamp when you are not using it.
• Don’t lose the magnets or the battery on the road.

Possible features in the future

• Dimming of the Kingbeam depending on the temperature
• Switch for turning the LED on and off without removing the clipper
• Strong plug-in cable between battery and the LED
• USB charging of the battery
• Bypass of the battery for direct USB Power Supply with a Step Up Converter
• Use the HDD bearings as optic

Open Questions

• How long will the magnets keep enough force for holding the equipment?
• How does the heating of the lamp influence the magnets on the plate?
• Can the optic for the Beamboarder created out of the HDD?

Known Issues

• The Clipper can get damaged after multiple usages.
• The Beam Boarder battery and lamp will fall off by strong impacts and vibrations caused by the street.
• The optic is not finished completely.

First I want to give credits to the people who helped me on the Beam Boarder until now.

Mello for your battery charger and your camera

Tine for reading my texts and her camera.

Manta for filming with his video camera and making an amazing night trip possible

Johannes for organizing more hard disc drives

Paul for giving lots of feedback and reading my texts

Dommay for crafting the perfect board for the beam boarder