This project is an ignition system for estes model rockets. It is powered by a 9V battery, so the rocket engine has a 99% probability of igniting correctly. It has a safety switch, an armed LED, and a launch button. It closely matches the safety specifications of the commercially available ignition system. this project is relatively easy, takes about 1 day, requires drilling, and soldering is optional.

disclaimer: I will not be responsible for any damage, personal injury, or death resulting from the use of this ignition system. always use the correct rocket, engine, launchpad, and recovery system. never allow anyone within 15 feet of the rocket when the ignition system is armed.

Step 1: Get the supplies

IMG_2478.JPG
Here is the list of supplies. They are all available at radioshack.
momentary-on pushbutton switch (launch button) Catalog #: 275-644 2.69
red LED assembly catalog # 276-270 $1.99
SPST lighted safety toggle switch Catalog #: 275-601 $4.99
9V battery clip (only 1 needed-pack of 5) Catalog #: 270-325 $1.99
9V battery Catalog #: 23-875 $3.99
5"x2"x2.5" project enclosure Catalog #: 270-1803 $3.69
4:40 round head machine screws (2 of the 1" length needed-pack of 42 assorted lengths) Catalog #: 64-3011 $1.99
4:40 hex nuts (6 needed-pack of 30) Catalog #: 64-3018 $1.99
#4 flat washers (4 needed-pack of 100) Catalog #: 64-3022 $1.99
#6 spade tounge connectors(2 needed-pack of 10 #6 and #8 connectors) Catalog #: 64-3044 $1.99
45 feet of 18AWG solid wire Catalog #: 278-1223 $5.99
Mini 1-1/4" Alligator Clips (2 needed-pack of 12) Catalog #: 270-380 $2.79
total cost: $36.08
wire stripper
electrical tape
drill with 1/4" and 1/2" bits(

Step 2: Prepare the project enclosure

drill two 1/16" holes through the front of the project enclosure as shown in the second picture for the ignition terminals.
drill a 1/4" hole in the middle of the top of the project enclosure and two 1/2" holes halfway between the middle hole and the ends of the project enclosure as shown in the third picture.

Step 4: Wire the components

schematic.jpg
wire the components as shown in the seventh picture. twist the wires that go to the rocket around the screws between the two nuts on the inside of the project enclosure. use the component leads and only as much of the wire as necessary. save the extra wire. connect the battery clip to the battery and secure the battery inside the project enclosure with electrical tape.

Step 5: Check the wiring

turn on the safety switch ensure that the wiring is correct. if the wiring is correct, the LED on the safety switch and the armed LED will turn on. turn off the safety switch and close the project enclosure. secure the project enclosure closed with the screws.

Step 6: Make the launching wires

make 2 long wires of identical length using all the remaining wire. they must be at least 15 feet long. crimp the spade tounge connectors onto one end of the wires and the alligator clips onto the other end.
construction is completed

Step 7: Launching the rocket

read the manual of your rocket. clip the alligator clips to the leads of the igniter in the prepared rocket on the launchpad. fully extend the wires and make sure that all people (including you), animals, and flammable objects are at least 15 feet away from the rocket. connect the spade tounge connectors to the screw terminals. turn on the safety switch to arm the rocket. press the launch button to launch the rocket.
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vignesh1230 says: Jan 22, 2010. 5:25 PM
I cleaned up the messy schematic (it works perfectly) and made a one that looks easy to understand.
Schenatic.JPG
greenie7888 in reply to vignesh1230Feb 22, 2010. 9:45 AM
What program did you use to make that? Please e-mail me a link, sam.greenwald@ymail.com
EET1982 says: Aug 4, 2012. 6:23 PM
Hi how are you? Love the instructable. I am building it tomorrow. Do you know how much current is needed to ignite the engine? I'm just curious is all. I see that if you buy the ignitor from Estes it needs 6v and your version has 9v. Which is fine. It's the needed current i'm confused about. Thank you in advanced for reading this confusing comment.
eatpie365 (author) in reply to EET1982Aug 16, 2012. 8:21 PM
I haven't specifically measured the current involved, but my understanding is that my version uses a 9v battery to apply more energy (higher voltage) to the ignitor than the standard version and reduce the probability that it fails to get hot enough to ignite the rocket engine.
One 9v battery is also easier to mount and connect to the circuit than 4 AA or similar batteries.
EET1982 in reply to eatpie365Aug 17, 2012. 6:34 AM
Cool. Sounds good to me. Thank you for your reply :).
RocketMan1957 says: Jan 10, 2012. 1:45 AM
Does the LED show Continuity for igniter or just power on? I know the cheap Estes controller has light that comes on for testing. I am trying to find plans/ideas for a 12V controller with battery near launch pad and relay control (so can use "speaker wire" in hand for mid power launches. Continuity could be tested at pad before moving back to safe distance for launch. Any thoughts?
eatpie365 (author) in reply to RocketMan1957Jan 10, 2012. 7:13 AM
On this project, the LED only indicates power. Continuity testing was not a primary consideration in its design.
The regular controller presumably does continuity testing by passing a small amount of current through the igniter. I don't know how small that would need to be to not actually ignite the rocket engine.
zanki_kitsune says: Aug 21, 2011. 10:03 PM
i think it is funny, they say never allow anyone withing fifteen feet of the rocket, but they give you about 9 feet of cord on the ignition.
rurun says: Jul 28, 2011. 4:18 AM
what can i use to ignitiate the explosive
eatpie365 (author) in reply to rurunAug 5, 2011. 12:02 PM
The model rockets are ignited by specialized igniters that are available nearby model rockets in stores. Each igniter contains some conductive material with very high resistance. When current is passed through an igniter, it heats up enough to ignite the propellant.
PyroWork says: Jan 21, 2011. 2:14 AM
what does a spade tounge connectors look like?and how does it work??
eatpie365 (author) in reply to PyroWorkJan 21, 2011. 7:00 AM
A picture of one is here: http://www.alliedelec.com/Images/Products/Small/512-4268.jpg

It connects a wire to something else, in this case a screw.
PyroWork in reply to eatpie365Jan 21, 2011. 10:43 PM
ohw..i get it..cn u make a vid in testing this??email me for some instructions..hehehe..adammoscosa@yahoo.com..NICE WORK BY THE WAY!!
eatpie365 (author) in reply to PyroWorkJan 22, 2011. 9:07 AM
Unfortunately, the device has been disassembled for a while so I can't make a video of it.
PyroWork in reply to eatpie365Jan 26, 2011. 3:29 AM
ohw..ok..
PyroWork says: Jan 21, 2011. 1:59 AM
Cn i use this to ignite fireworks??(^_^)
i really wanna try this!!!THIS IS SOOO COOL!!!!!!!!!!!!Best instructions ever..this is the only instructions that i understood..NICE ONE!!
rocket master says: Nov 30, 2010. 7:02 PM
would it be possible to replace the led with a buzzer that goes off when you press the launch button?
rocket master in reply to rocket masterNov 30, 2010. 7:06 PM
If so, could you provide a schematic?
chemist711 says: Jun 18, 2008. 7:59 AM
Ok awesome, so does this mean that I can literally just strip back the insulation on the wires and splice them at one point, or do I need some special adapter that they all are connected with? Thanks
temp in reply to chemist711Jan 7, 2010. 4:18 PM
you can just have a battery and a switch but this idea is saver.
rocket master in reply to tempNov 30, 2010. 6:58 PM
I just used a battery and a 2ft long wire >D
eatpie365 (author) in reply to chemist711Jan 6, 2009. 8:25 PM
Yes, you can do what you described in the comment.
chemist711 in reply to eatpie365Jan 7, 2009. 7:38 AM
Thanks I am gonna try it tomorrow
eatpie365 (author) in reply to chemist711Jan 7, 2009. 7:16 PM
You're welcome.
TSC says: Sep 6, 2010. 5:24 AM
So somebody did make one of this I was going to try make one but now I can try makeing you'res!!!
chemist711 says: Jul 28, 2010. 6:24 PM
Ok. The funnythibg is have followed this and built it and it works. I am still trying to understand how the current is flowing through this circuit. Could someone explain to me where the current is entering the circuit, where all it goes in what order once inside the circuit, and finally where does it exit the circuit and does it exit the circuit At more than one place? Help would be appreciated. Thanks
eatpie365 (author) in reply to chemist711Jul 29, 2010. 7:35 AM
The current enters the circuit at the battery. If the safety switch is closed (on), the current follows one of the following paths: 1: through the LED in the safety switch and back to the battery 2: through the other LED and back to the battery 3: If the launch button is closed (pressed), the current goes through the launch button, through the ignitor in the rocket, and back to the battery. All the current leaves and enters at the power source (battery) - that's what makes it a circuit.
chemist711 says: Jul 29, 2010. 6:02 AM
HHHHEEEEEEELLLLLLLPPPPPPP, can anyone answer my post below? thanks.
sd229 says: Jul 27, 2010. 7:55 AM
If I wanted to add a second LED that lights up when the launch switch is pressed where would it go? Thanks, again.
eatpie365 (author) in reply to sd229Jul 27, 2010. 8:25 PM
The LED would go between the launch button and the rocket. Be sure to connect it with the correct polarity. A resistor would probably not be necessary because of the resistance of the ignitor in the rocket.
sd229 says: Jul 26, 2010. 10:55 AM
I've just bought the components from Radio Shack UK and the toggle switch that came only has two connection points and a hole on the bottom. What should I do? Thanks
DSCF7894.jpg
eatpie365 (author) in reply to sd229Jul 26, 2010. 5:23 PM
Connect the wire that would go to the 'power' terminal to one of the connection points on the switch. Connect the wire that would go to the 'acc' terminal to the other connection point.
sd229 in reply to eatpie365Jul 26, 2010. 5:58 PM
Brilliant, thanks for your fast reply!
zoltzerino says: Sep 15, 2009. 10:06 AM
I made this the other night (not from this 'ible though). the rocket is a Cheap Estes thing, I launched it with a C5-3 engine and it went around 300-400ft.
DSC00615.JPGDSC00619.JPG
cdousley says: Aug 8, 2009. 10:53 AM
the ground wire has negative charge from the led wire does it have to be connected to the ground on the switch
eatpie365 (author) in reply to cdousleyAug 8, 2009. 11:30 AM
Yes. The ground wire from the safety switch, the wire from the LED, and the wire from the rocket should all be connected to one terminal of the battery.
cdousley in reply to eatpie365Aug 10, 2009. 5:19 PM
ok
engineer_01 says: Jun 11, 2009. 1:07 PM
ur really good at drawing
eatpie365 (author) in reply to engineer_01Jun 11, 2009. 9:45 PM
Thank you for the compliment.
ArvindTheNinja says: Apr 25, 2009. 1:41 PM
i need help. when i type in the model number for the lighted safety switch, it comes up with a similar switch that isnt lighted. i know it doesnt matter much but i would just prefer a switch like that.
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