Saturday, May 24, 2008

How To Make a Pocket Stove from a Soda Can

Introduction: So I'm sure that all of you have seen some of the articles out there about making camping/hiking stoves out of a soda can. I look at them all the time, but they have one big flaw. Most of them don't have enough pictures, don't explain how the stove works, and have very vague directions. I am going to try to write an article that contains all of these things, and is easy to understand. The stove that I am going to show you to make can be used for camping, hiking, sitting around, making light, or just watching stuff burn.

Instructions:

  1. Get two cans. Make sure that they are empty and dry on the inside.


  2. Cut the bottom off of one of the cans. Make a smooth cut (I used a razor blade). The cut should be a little further up the can than an inch.


  3. Do the same with the other can.


  4. On one of the cans, you should crimp the top. Do this by gripping the can with a pair of pliers every half inch and twisting.


  5. Put the two bottoms of the cans together. The crimped can goes on top and inside of the uncrimped can. Press tightly to make sure that there is a good seal.


  6. Use a thumbtack to place a small hole in the lip of the upper can. The metal is fairly thick at this point, so it might take a little bit of force.

  7. Repeat this every 1/2 to 3/4 of an inch all the way around the can.


  8. Place a small group of holes (I used seven) in the center of the can that you just poked the holes around.


  9. Done
How it works:
  • The small group of holes that we cut on the top will be used for filling the stove. You have a few choices of fluid, but you can use any alcohol over 70%, or 140 proof. You can use denatured alcohol, HEET, or even vodka. Whatever works is fine, just don't use anything explosive like gasoline. I am going to use plain rubbing alcohol.


  • Once the can is filled, we are going to cover the group of holes with a penny and fill the "well" that the can makes with our fluid. The penny is used to make sure that the fluid stays in the "well" and does not go into the stove.

  • Carefully light the fluid that is filling the "well".


  • The burning fluid on top of the stove causes the metal that the stove is made of to heat up, which boils the fluid inside. When the fluid starts to boil, it turns into a flammable gas that starts to escape from the group of holes that we punched around the top. The flaming fluid on the top ignites this gas.


  • Once the fluid on top is used up, you end up with just the gas being burned that is coming out of the row of holes. This will continue to burn until the fluid inside runs out, or you cover with something and deprive it of oxygen.

  • Here are some pictures of the stove working: (sorry for the bad picture quality)



Monday, May 12, 2008

How to Blind a Camera Using a Laser

In this article I am going to explain to you a simple mechanism that you can use to blind a security camera, webcam, tv camera, camcorder, and most other optical recording devices. The idea is very simple, when a powerful laser is pointed directly at the lens of a camera, the lens is overwhelmed and cannot see. However, it is very difficult to precisely aim and keep a laser still from any practical distance. Here, I will show you an easy remedy for this problem.

    Materials


  • A powerful laser, can be any color that you choose. Your range will depend on the power of your laser. (I suggest the C.O.R.E. by Wicked Lasers)
  • A gun scope, binoculars, golf range finder, or other magnifying eyepiece. In this article I will use a gun scope.
  • A small tripod.


    Construction


  1. Start by attaching the laser to the gun scope in a fashion shown below. You can use any means of attachment that you want. Duct-tape, super glue, rubber bands, or string work well. Just make sure that the laser is on snugly and can be adjusted easily.


  2. Attach this unit to your tripod. Make sure that the whole unit is steady and well attached. If you plan on using this unit outdoors, it might be helpful to cover any critical components with a plastic shopping bag.




    Use


  • Before any use, the scope and laser must be properly aligned. To do this you should position the unit at the approximate distance from the camera that you will be using. Looking through the scope, move the laser into the center of the crosshairs, and lock the laser into place.
  • Move to the location that you are going to use, it is best to have a straight shot at the camera.
  • Look through the crosshairs and aim the unit at the target camera.
  • Turn your laser on and fine-tune the positioning of the dot onto the camera. You should know that the laser is aligned properly because the laser will cause a glare when it reflects off of the lens of the camera.
  • Lock the laser into the "on" position. This can be done simply by taping the button on most lasers down with a piece of strong piece of tape or tightly tying a piece of string around the laser over the button.

    Effect


    The following are demonstrations of the effect in action. Note the improved effect as the range is decreased. Also, using a green laser like the one mentioned above from Wicked Lasers will result in MUCH better result.







    In my experiments using the C.O.R.E., the results were much better. The camera was completely disabled and all that resulted was a white screen. This was from a 15m range using a Microsoft WebCam. I would highly suggest using at least a 5mW green laser over the 1mW red lasers that are shown in the above picture. For an ever better result, you could use a combination of red/green lasers, which would making filtering the image nearly impossible.

    The images used in the article are used with permission by Michael Naimark, from this website, where there is a lot more information about this topic.