The finished launcher, the electric tape rolls are just to show your the size of the launcher.
Archive for August, 2009
The fulcrum for the launch lever is a piece of scrap wood about 20 millimeter square and 100 millimeter long, it should stick out from the base, which is 80 millimeters wide. Note that we have sanded or filed one edge so that the lever slants down towards the long arm... This is important for the good working of the launcher!
The lever, a paint stirr stick or piece of sawn wood about 35 centimeter long, (the same as the base board of the launcher), is glued to the fulcrum, and secured with two small nails or a small screw. Use the yellow carpenters' glue from a hardware store. That is acually a good all purpose glue!
Launcher base and lever. The base at the left can be any piece of plywood or particle board, in this case it is a piece of laminated scrap particle board, about 30 centimeters long and 8 centimeters wide; note the two notches sawn or carved-in at each side, note also the location, try to make the notches as in the example. The lever was cut from a plank, but a paint stirr stick will perfectly do the job. You can ask the paint shop to donate a few to you for this project, or you offer to pay, they cost only maybe 25 cents.
A medicine cup is glued with an electric hot glue gun to the lever and then secured with a screw, this makes it extra strong. The screw should be short and not stick out from the bottom of the lever. You can get these medicine cups at any pharmacy, ask and explain why you need it and they will be willing to give you two or three, one you use the others are back-ups!
The launcher is assembled, now you need to add some colour. If you are eager to launch the first object go ahead, watch your eyes, safety glasses should be worn! Make also sure no other persons are close and only launch light objects such as the cork, a marshmellow or bouncy ball.
Done...this is the assembled and decorated launcher. The decorations are done with coloured electrical tape it always add much needed colour to a project.
Lets make a real, good sounding drum. All you need is a discarded plastic pail, some awning fabric, rope, a few wooden sticks and some tools you can find around the house or you might approach a trades person or a friend or family member who has a workshop. Feel free to visit a local shop, the trades people or store owners will try to help you when you show what you are planning to make. Most materials in this project are scrap pieces in any workshop! And most adults will try to help you. Besides, you will build contacts and you will get a better feel for practical work in technology.
The drum made from a plastic pail, a polyester awning material, some polyester rope, wood sticks and some youthful ingenuity. Give it a try, but get some help and supervision of an adult!
I our latest version we omit the wood sticks and weave the rope directly through the holes in the side of the bucket, you can drill all the twelve holes at the same distance from the top, just experiment a little and you will find the right set-up for your own project. Afterall, these projects are meant to tickle your imagination and make variations on these projects. Good luck! The ten boys and girls at the Boys and Girls Club in Kingston, Ontario, were enthusiastically playing their drums at the end of the projecthour, the whole building resounded with the drum beats, WOW…
You need about two meters of polyester rope, about 5-6 millimeters thick. Polyester rope does not stretch when under tension, so the drum skin remains tight after you tighten it as bests as you can. Note the bowline know and the taped ends, this prevents unraveling of the rope. You can also melt the ends with a hot soldering iron or a candle flame, or barbeque lighter, but you need to do this with adult supervision, for sure!
The rope has a bowline knot at the end, if you don't know this common know ask a sailor friend, a girl or boy scout, an handy person, or check it out on the internet, it is a very useful knot to know. It is easily undone when needed and it holds very well under tension.
Four sticks square or dowel wood about 20 millimeter in diameter. Dowel wood is expensive, we cut these from some scrap pine or spruce, ask a friendly carpenter or hobby person to make these for you! They should be long enough to stick out on both sides of the pail, about 25 millimeter, see later stages below.
A plastic pail with the bottom sawn out with a sabre saw or any other too; be careful, adult supervision needed! Eight holes are drilled in the side, two opposing each other and each pair spaced below the other at least one hole diameter, and also each pair 90 degrees rotated with the previous pair. Wow that requires some layout with a marker! Use a hole saw or drill about 20 millimeter in diameter. You can also drill a smaller hole and file it out to about 20 millimeter diameter.
Drum body is a plastic pail with holes drilled in the side which the sticks used for anchoring the rope to tighten the skin.
Drum skin made from a awning fabric that is a polyester or similar material coated with a plastic layer. The holes are burned into the fabric using a hot soldering iron or other hot metal rod. Be careful, adult guidance is needed!
The drum body upside down on the skin, note the pattern of the rope woven through the eight holes in the skin. The rope is hooked around the sticks, and then pulled tight going around and around to tighten it evenly.
Let’s make a kaleidoscope and impress your friends, or better: built one together so you both can have fun using it.
Example of a colour image through the kaleidoscope.
Three acrylic mirror strips from the plate glass store. Tell the manager you need three strips about 20 millimeter wide and about 230 millimeter long. Maybe you get it for free!
The mould or pattern board is just any piece of wood with eight small nails to keep the mirror strips apart at the right distance, about 4 millimeter. Any other method of spacing is also OK, for example use match sticks
The mirror strips are off the mould and have the right clearance between them. Note the reflection of the photographer.
The wire has been bent so that it cradles the marble. The wire looks like a hair pin with the curved end bend upwards like the tip of a ski. Just keep fiddling with the wire till the marble is held snug by the wire while it can easily be rotated.
This is the proper position of the marble at one end of the kaleidoscope, it has to cover the end for the best effect
The finished kaleidoscope, amaze your frieds with the most bizarre colourful patterns through this optical insstrument
