Step 1: Materials List

LED throwies consist of only a few inexpensive parts and can be made for ~$1.00 per Throwie. You can reference the parts list below or download the attached spreadsheet for more info on parts, part's numbers, vendors and application notes.

Part: 10mm Diffused LED
Vendor: HB Electronic Components
Average cost: $0.20 avg per LED
Notes: Cost reductions for larger quantities. Comes in red, blue, amber, white in both diffused and clear. Diffused works better than water clear for the Throwie application. HB has even created a Throwies packs page with deals on 10mm LEDs and lithium batteries!

Part: CR2032 3V Lithium Batteries
Cost: $0.25 per battery
Notes: Cost reductions for larger quantities. With the 2032 Lithium batter, depending on the weather and the LED color, your Throwie should last around 1 -2 weeks.

Part: 1-inch wide Strapping Tape
Vendor: Your local hardware store
Cost: $2.00 for one roll
Notes: One roll will make many throwies

Part: 1/2" Dia x 1/8" Thick NdFeB Disc Magnet, Ni-Cu-Ni plated
Vendor:Amazing Magnets
Cost: $13.00 per 25 magnets
Notes: Cost reductions for larger quantities

Part: Conductive Epoxy
Vendor: Newark In One
Cost: $32.00
Notes: The epoxy is optional.

Step 2: Test the LED

Test your LED to determine color, brightness and functionality. Pinch the LED legs, or leads, to the battery terminals. The longer LED lead, called the anode, should be touching the positive terminal (+) of the battery and the shorter LED lead, called the cathode, should be touching the negative terminal (-) of the battery.

Note that the positive terminal on the battery has a larger contact surface than the negative terminal. The positive terminal extends around the sides of the battery. Don't let the cathode lead of the LED accidentally touch the positive terminal of the battery. This will create a short and cause the LED to function improperly.

For more information on LEDs click here.
For more information on batteries click here.

Step 4: Tape the magnet to the battery

Now, place the magnet on the positive terminal of the battery and continue to tightly wrap the tape. The magnet should be held firmly to the battery.

If the magnet is stuck to a ferromagnetic surface, dont pull on the LED throwie. Apply a lateral force to the magnet and slide it off the surface while lifting it with a fingernail or tool.

Remember to keep the magnet away from conventional hardrives, credit cards and other data storage devices.

Step 5: Toss your Throwie

The LED throwie is ready to be tossed onto a ferromagnetic surface. Practice tossing your throwies. Work on your accuracy and your own personal technique. Every throwie wont stick every time, but if you toss them gently, they will stick eventually. Get them up high and in large quantities for greatest enjoyment.

Step 6: Plan a campaign

Now, find a building or structure that will attract the magnets, form a crew, wait until night, and get some throwies up. If you do it around a crowd of people, they will probably try to get into the act. It can quickly dissend into chaotic fun. Give a hand-full of throwies to a stranger and let them get up too. Remember, Throwies are only a temporary alteration of your local environment. Depending on the color, Throwies can last upto two weeks, but you arent going to cause any permanent damage, so most property owners wont mind. And The NYPD loves throwies!

Click on this link to see the LED Throwies in action!

Step 7: Other applications and upgrades

Other applications:

Other than tossing it, you can also use your LED throwie to write in the air with light while taking a long exposure flick. You can put them on your bike as an additional reflector. You can put the on surveillance cameras to make them more visible at night. You can use them to play a version of bocci ball on a magnetic surface in the dark.


You can make a better LED throwie by using shrink tubing on each lead to make sure they don't short to each other or the battery. This upgrade will allow you to bend the LED so it faces in the direction you choose. You can also dip the throwie in epoxy, silicon or potting compound to make an all-weather LED Throwie. A resistor in series would allow you to increase the throwie shelf-life. Bigger batteries = longer life. Stronger magnets = increased stick probability. You could add a solar panel, photocell, etc...Have fun.

User Upgrades:

Flickr instructional set for thowie on/off switch mod -- by A. Joyce, aka. EverythingDigital
Kirbsome!4 years ago

Throwies on steroids -

7 LEDs arranged in a ring
LED Ultrie.jpg
I have great news, you are today's winner of the "I Made It" Challenge for the month of june. Thank you so much for being a part of the instructables community and encouraging authors to post more projects!

For winning you are receiving a 3 month pro-membership.
fun with LED throwies
I have posted a how-to on making throwies with removable tabs where you can pull it out to turn the LED on and slide it back in to turn it bad off. It's not very hard to implement, and is quite useful for conserving battery power.

Here's the link:

I'm also working on throwies that automatically turn on upon sticking to something and off when they are removed (as suggested above), and I have a few prototypes working but there are still some bugs to work out.
Q-Branch (author)  everythingdigital8 years ago
I have included your how-to on the G.R.L. Throwies site and in the upgrade section of the throwies instructables post. Thanks so much for the mods and looking forward to the next rev!
clapfilk8 days ago


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Cronos511011 month ago

When I started reading this, I thought, $1? That's okay, but how long do they last? It's a really cool idea to cheer up an area, but not so much if you only get a few hours. Then I saw you get 1-2 weeks. Simply brilliant!

fadecomic2 months ago

I'm going to take a handful of these in blue to a con dressed as Goku. KAMEHAMEHA!

generalsocial2 months ago

I just took a throwie, added a snowflake as a diffuser. It's now a "Snowie!".

gazumpglue2 months ago

These are really neat. It's a shame Christmas just passes. The kids would of had a lot of fun with these. There is always next year!

harinderiniz5 months ago
Gonna Try it

Same here

ChippMarshal3 months ago

These are really neat. It's a shame Christmas just passes. The kids would of had a lot of fun with these. There is always next year!

tbuchanan24 months ago
Where do you get the leds
flyingpuppy5 months ago
Where is the epoxy used?
Mariska Botha7 months ago
Awesomeness! Very cool
BunnyRoger7 months ago
AAAAhhhhhh I love this...
I can see myself having a LOT of fun with this. Thank you for sharing.
MAApleton7 months ago
Are these the same type of led lights they used in the step up movie? I think it was the last movie. Thanks
mf7387 months ago
Hi,anyboday like buckyballs and buckybars,they also very vest diy toys,you can find them here: 
mf7387 months ago
Hi,anyboday like buckyballs and buckybars,they also very vest diy toys,you can find them here:
Very detailed Information I think they use this in move. I think step up.
Try to experiment this thank you for the Materials List and tutorial.
physicx9 months ago
can ihave one of your experiment
technicgeek109 months ago
I'v made one of these before It, but mine was more like a piece of c*** compared to yours! good job!
Kelly0210 months ago
nice idea!
Thanks for adding to the legitimacy of this practice. I've been doing this for years. It's amazing the valuable things people throw out
frankygtd1 year ago
here you can find magnets on
frankygtd1 year ago
I think these ideas are interesting and this site is very good.
JensonBut1 year ago
your doing it right.
Thank's also for PDF file for downloading!
Thanks for youre awesome guide!. Great job on the code aswel.

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