Powerful Rocket Igniters

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Posted in TechnologyElectronics

Introduction: Powerful Rocket Igniters

About: HI, I am zander, I'm 16 and love to build things. thingiverse.com/-Zander

Hello, I'm designing a new rocket and I needed to make some igniters so I went into the garage and tested about a dozen different styles and I settled on this simple, and easy design.

Below you will find all the steps in order to reproduce my product.

Step 1: Supplies

Materials

The best option are the ones without insulation however I did not have any.<br>
Cotton balls are just the same as the pads I used. 
I like the clear heat shrink. It allows you to see if you are done packing the cotton.<br>

Tools

  • Wire strippers/cutters
  • Flat Pliers
  • Scissors
  • Pointy Tweezers
  • Lighter/hot air gun (air will work better as to not light the cotton.)

Step 2: Prepare the Paperclip

I started this step by grabbing my pliers, cutters, and paper clip. I used the pliers to straighten the paperclip out, and then I stripped all of the insulation off of the wire.

Step 3: Shape the Prepared Paperclip

With the stripped paper clip, I bent it 180 degrees and got the legs as close as I could before they would twist around each other. Then I bent the legs out about 45 degrees. A half centimeter out, I bent the legs inward to get the straight leads. Lastly, I used my wire cutters to even off the legs.

Step 4: Pack the Shaped Paperclip

This next step will require the heat shrink, cutters, tweezers, cotton, and the bent paperclip. You will want to start off by placing the heat shrink on the tip of the paper clip and clipping the excess off leaving about 3mm above the paper clip. Next, you will want to tear off a piece of cotton and roll it around to get it tighter, then use the tweezers to push the cotton into the heat shrink until you cannot stuff any more into it. you will want to trim off the excess and repeat from the other side.

Step 5: Shrink the Heat Shrink

Lastly, you will want to take your heat gun/lighter around the heat shrink. I like to run the heat around the cotton to get rid of the stringy bits.

Step 6: Finished Product

Congratulations you have a finished product.

I used a 12VDC Lead Acid Battery, if you use the same battery you will need some low gauge wire or some silicone insulated wire to prevent spontaneous wire degradation. If you have a way to check for a flame you can break the circuit to stop overheating.

If you find it is hard to ignite a motor you could try to tear some cotton. Put it in a cup and sprinkle some Potassium nitrate( KNO3 ).

Please leave a like and subscribe to catch my upcoming Instructables.

Step 7: Extras

I've included a beaker full of used experimental igniters.

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    8 Comments

    So how long do you leave the current switched on ? How much current does it take ? Could a reistor be used on the battery side to prevent a dead short condition and still ignite the cotton?

    2 replies

    The battery is only connected for a few seconds. I'm not sure how much current it takes. Also with the added length of wire, you increase resistance so if you are worried then using some long wire and twisting them around each other to increase the length of wire thereby increasing the resistance. The batteries I use are not expensive so I'm not too worried about it.

    Well I made one and put 4 amps on it at 12 Volts and it barely got warm . I think this propasition is a fizzer!

    Wow, that's amazingly simple! I kept waiting for some exotic material to be added. Thanks so much for sharing this!

    4 replies

    The cool thing is if you ever want to put anything else into the heat shrink you can. I was thinking about putting some oxidizer into the cotton to make sure it ignites inside a motor.

    I was wondering if substituting polyester fiberfill for the cotton might ignite easier and/or burn hotter, but that's strictly a guess, since I'm ignorant of chemistry. I guess there'd be a fine line between an efficient ignition and just blowing up your rocket!

    From what I have found on the internet polyester needs higher temps(around 400C compared to cotton around 200C) to burn and it drips burnt polyester. I'm sure you could get it to work but cotton would be a lot cleaner.

    I wonder if soaking up a little denatured alcohol in the cotton just prior to launch might make it combust a little more enthusiastically?

    No need to reply; I'm just sort of thinking out loud. I saw what was most of an old black powder gun at an antique mall recently, with the main missing part being the trigger mechanism. I've been wondering how such a gun might be electrically ignited, so naturally your clever and simple rocket igniter fired my imagination :) Good luck with your experimentation and thanks again for sharing.