Fun & Games

The latest DIY ideas, techniques and tools for bikes, rockets, R/C vehicles, toys and other diversions.

Weekend Projects – 10-Rail Model Rocket Mega-Launcher

Weekend Projects – 10-Rail Model Rocket Mega-Launcher

Complete instructions for this Weekend Project can be found at http://makeprojects.com/Project/10-Rail-Model-Rocket-Mega-Launcher/243/1

Nothing is more exciting to model rocket enthusiasts than a multi-rail launcher that can blast several rockets off at the same time. For rocket clubs and events, it’s almost essential to keep things moving at an exciting pace with these types of launch systems. This 10-pad mega-launcher was developed for Cub Scout Pack 1346’s rocket derby. And now you can build it too.

This system gives kids (of all ages) the fun of pressing their own launch buttons, and for added drama, sounds a klaxon before each launch. For the finale, a “Mega Launch” switch shoots off all 10 rockets at once.

To minimize the chance of an unfired rocket left on the pad, the launcher also has always-on igniter continuity checks, using LEDs to show which igniters are ready. Blocking diodes allow dual-use of the wire harness โ€” for continuity check and launch voltage โ€” thus halving the number of wires to the launch bar.

To show kids and adults that the launcher isn’t actually as complicated as you might think, the workings of the system can easily be seen behind clear plastic.

Weekend Projects – Game Show Buttons

Weekend Projects – Game Show Buttons

Complete instructions for this Weekend Project can be found at http://makeprojects.com/Project/Game-Show-Buttons/1916.

In this project, taken from Charles Platt’s book Make: Electronics, we’re going to breadboard a fairly complex circuit using 555 timers and an “OR” logic gate.

Using these and some other, common components, we’ll create game show buttons. When one button is pressed, it automatically locks out the other one until the quizmaster flips a reset switch.

An “OR gate” is one of several types of basic logic gates. The logic of ORs are, as the name suggests, if input A or B is true (on), output X is true (on); thus, in this design, if either player presses their button, the circuit will go true (on), locking out the other push button, and can only be reset via the toggle switch. This circuit is ideal for two-person quiz contests!

“I’ll take ‘Cool Projects’ for 100, Alex!”