Introduction: Radio Controlled Match Igniter
A while ago I decided to try making a Rube Goldberg machine. (If you don't know, a Rube Goldberg machine is an over complicated machine that does a simple task. They are run by a chain reaction, sort of like a domino chain.) I thought it would be really cool to find some way to include fire. I came up with two possible ignition sources: a match or a lighter. I decided that a lighter would be to hard to get to light as part of a chain reaction, so I started working with matches. I tried several ideas for getting something to strike a match, with no success.
Once I came up with a device that would light a match by dropping a weight, I couldn't just stop there. I wanted to make it better. I decided that making the weight drop by remote control would be cooler than just dropping the weight myself.
At this point, I'm probably not going to use this in a Rube Goldberg machine, mostly because now that I have fire, I don't know what to do with it. But oh well... it looks really cool!
Answers to questions for Make to Learn Youth contest
What did I make?
I made a device that will light a match when I flip a switch on my remote control. The radio receiver turns on a motor that pulls a small weight over the edge of my workbench, which in turn pulls off a larger weight. This weight pulls a match along a striker, igniting it.
How did I make it?
I was originally trying to make it for a Rube Goldberg machine, so it needed to be easily started. A falling weight works well for this. I originally ran into problems with the match not staying in contact with the striker, but I solve that by using rubber bands and a ball chain. The rubber bands keep pressure on the match head, and the chain allows the pivot to move.
Where did I make it?
I made it in my Dad's workroom. I have been borrowing his tools and make random stuff for as long as I can remember. Sometimes doing this is useful, especially for science classes. I helps me understand how things work.
What did I learn?
I realized how complex a simple task can be. I don't think anything of lighting a match... hold the box in one hand, strike the match against it with the other. Trying to get a machine to do the same thing was very challenging. It really helps me appreciate how amazing the human body is, that we can do such complex things without much work.
Step 1: Materials
I found everything I needed to make the igniter just laying around my house. Here's the list of items:
A piece of scrap 2x4
A small plywood scrap
An old matchbox with a striker in good condition
Metal coat hanger (or other metal rod)
Small weight (you could use string, but it breaks every time you drop the weight, and is a pain to retie)
Small ball chain
If you want to make it radio controlled like I did, you'll need a few more things, which I'll list later.
Step 2: The Base
I'll try to explain how I made this as best as possible, but looking at the pictures will be the easiest way to figure out what I did.
How the igniter works is it pulls a match along a striker when a weight is dropped. Things get tricky when one end of the match is held stationary, because then the matchtip will follow a curved path and not stay in contact with the striker. Using the ball chain and rubber bands allows the match to remain in contact with the striker.
The piece of 2x4 is what everything is attached to. The first thing that needs to be attached is the striker. Cut the striker off an old matchbox, and tape it to a scrap of plywood. Then nail the plywood to the 2x4, near the end, with the striker facing away from the edge (Look at the picture).
Step 3: The Match Holder
Now the device needs something to attach the match to. I used a piece of metal coat hanger for this. I cut a piece a few inches long and bent a loop in the end to put the rubber bands and ball chain through. When guessing how long to make the piece, guess on the long side and cut it to size later. Again, the pictures make this much clearer.
Step 4: Putting It Together
Hook the rubber bands around the plywood. A match will be taped alongside the the coat hanger to use the igniter, so make sure when you put the tip of the coat hanger on the striker, there is some pressure. If there is too much pressure, then cut the hanger shorter. If there isn't enough pressure to light a match, then either get a longer piece of hanger of find smaller or stronger rubber bands.
Make a loop with the ball chain and attach in to the hanger. Put a nail in the 2x4 to hook the chain on, so that the hanger is just touching the striker at its furthest point (an edge).
Step 5: Using the Igniter
This is the fun step. Tape a match to the coat hanger. Have stick out 1/8 to 1/4 inch from the end of the coat hanger, or however far is necessary to get the right pressure. Tie a piece of string to the match, and tie a weight to the other end. Clamp the 2x4 down so it won't get pulled over the edge by the weight.
Before dropping the weight, check to make sure it's safe. If the tape doesn't hold, the match might will start swinging around on the string. So make sure nothing in the area will catch on fire if a match goes by. Also, be careful where you put your feet. It would really hurt to drop a weight on them.
Now that you've checked for safety, go ahead and drop the weight.
Step 6: Remote Control
Making the match light by remote control is even more fun. To do it, you need to get the weight to drop. I did this by hanging the weight over the edge of my workbench, then tying a smaller weight to the big one. I tied the small weight to a little motor and hung that over the edge. By using a chain reaction, I was able to drop a several pound weight with only a small motor. To do this you need:
A small weight (I used a eye bolt)
A small motor
Another piece of 2x4
A radio control remote and receiver. I scavenged mine a while ago from an old RC truck. If you have on lying around, save yourself the trouble and just tie the weight to the truck.
Step 7: Adding the Motor
Experiment with tying the weights together and balancing them, until the small weight requires little force to pull off and tip the big one. Instead of tying the string directly to the motor, I threaded it through a staple in a board on the ground first. This is so when the weight drops, it doesn't drag the motor and receiver to the ground. I hot glued the string to the motor shaft. Now set up the match like normal, grab your remote, and amaze your friends!