Contactless dynamo powering bike safety lights

Step 2 Hard drive magnets

Now you will need to find some neodymium hard drive magnets. I used 3 of them on my rear wheel, you could use how many you want as long as you are able to firmly attach them.

Comments

[kent1956]

Metal Drilling 101.

-Buy more expensive carbon drill bits.
-Use a cutting oil, and be liberal with it. It will help to cool the bit and keep it from melting and help to clean out the metal bits from the hole.
Cutting oil can be bought in small 8 oz. bottles
-Use a low speed, high speed causes the bit to make small metal bits and can lubricate the drill bit, causing it to ride above the metal you are trying to cut through.
-Drill bits are actually cutting tools, look at one, they normally have two cutting flukes (surfaces). You will know you are using the correct speed when you get a nice ribbon of metal, rather than a lot of small chunks.
-Keep good hard force on the drill, if you don't it will again make small chunks and just float on them above your metal surface.
-For very hard metal, It becomes necessary to start with a smaller pilot hole, and enlarging it drill size by size to your desired hole size.
I don't think these magnets have a very hard metal strap, they are not made for really hard abuse as other metal parts are, so this should not be necessary.

vbnicolau,

I have used the FreeLights and am not impressed with them. They are way too dim. But the idea is good. The paper from the NM students is good information. I like the way you have made use of salvage parts.

I would consider ways to make this all waterproof, as I commute come rain or shine. PVC tubes with caps could be used to house the relays, with a small hole on the bottom side for the wires to come out, sealed with some silicone.

Thanks for sharing this, over all a great idea, and a great presentation here.

[yonutzky]

I have only one screw hole in my magnets. I tried to drill another hole in the panel the magnet sits on, with an ordinary drill, but it only dented the metal. It won't go through. Any suggestions?

Thanks

[bricabracwizard]

Use a proper drill for metal, they are a bit more expensive but they cut through metal like its cheese. Another thing is keep the drill cool while drilling they will stay sharper longer.

[The Insignificant User]

Something I've found that helps is to drill the hole and then use a hammer and a sturdy roofing nail to drive the rest of the way through. However, this works best with smaller diameter holes, so if you intend to use a larger bolt to hold it in place, that might not be the best method.
Best of luck.