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ArcticMyst Security by Avery

The Ultimate Machine - Probably the stupidest thing I've ever built

Joined
Oct 24, 2008
Messages
1,057
Points
48
Also known as the Leave Me Alone Box or the Useless Machine; it is probably my most useless yet awesome creation ever. The interface is simple. One toggle switch sits on top of a wooden box and when it is flipped an arm springs forth from a hidden hatch and shut the switch off and recedes back into the box.

I showed my completed box to my buddy and he exclaimed "this is the dumbest thing I've ever seen! Why would you make this!?!" Yet he continued to play with it for like 10 minutes! hahaha.

So I'm making this thread to not only show off my Leave Me Alone Box but also to show you all how I made it so you can make one. :D



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At first it seems pretty simple to make but actually it is moderately complicated. You couldn't just wire up the arm motor to the battery via the switch because how would the motor then retreat back into the box???

The idea for this box is not mine. The original schematic utilized PIC micro controllers and complex circuity to control the motor's movements. But I thought this was WAY overkill for such a trivial novelty. Plus even in standby the circuity required current, so the electronics are never truly off (no current is drawn from the battery).

So I designed my own box that uses only 4 parts, 2 switches, a battery, and a standard RC servo. However there is a catch, the forgoing of the complex circuity requires some modding of the RC servo itself. But it's easy to do and I'll post links to the required components.

1. First you'll need a 3PDT (triple pole double throw) on-on toggle switch, it has 9 connections on the bottom.
3PDT ON-ON MINI-TOGGLE SWITCH | AllElectronics.com

2. Then you'll need a standard SPDT momentary micro switch.
S.P.D.T. MINI-SNAP-ACTION SWITCH | AllElectronics.com

3. 4.5v or 6v battery pack

4. A standard RC servo.

5. A wooded jewelry box

6. Aluminum rod

7. Various tools and glue.

Here is how it works. The micro switch is located at the base of the box and that tells the servo when to stop, so it doesn't hit the bottom of the box. When the box is standing by the arm is holding the switch down. When the toggle at the top is flipped it provides power to the servo to move towards the toggle switch and it releases the micro switch at the bottom. The micro switch provides redundant power to the servo. The toggle switch at the top also is wired to reverse the polarity to the servo causing it to move in the opposite direction once flipped. Since the micro switch inside the box is providing redundant power the motor continues to run even though the toggle switch is off. The arm retreats until it hits the micro switch and it cuts power to the motor. Power is only drawn from the battery when the arm is actually moving.

If you understand how it works then it becomes WAY easier to make.

Now, about the RC servo, normally an RC servo has 3 wires, usually yellow, black, and red. The original plan used those connections but for my schematic you'll have to mod the servo a bit, but it's easy. You simply need to remove all the circuitry and solder two wires to the main motor itself. So when 6v is applied to the servo it moves in one direction and when the polarity reverses the servo moves in the opposite direction.

Taking apart the servo is easy. There are usually 4 screws on the bottom, remove them. Holding the servo together, remove the bottom plate and unsolder the main motor from the circuit board. You should notice the two biggest solder connections on the board, that's the motor. Just remove the board and solder two connections to the motor directly, don't worry about polarity. Also there will be a potentiometer in there. If you can remove it, do so, but it may be attached to the gears in the servo. But be careful now because most servos can only move like 220 degrees before they have a mechanical stopper. The motor will be fighting against the gears is you leave the power on for more than a sec.

Use a hacksaw to cut the lid of your box in half and put one of the lids on a hinge. I made my arm out of aluminum rod bent into a U shape and I used two screws and a drill to mount them on the servo horn.

The hard part is aligning everything up so the arm horn hits both switches nicely. I used hot glue to mount everything in the box. Make sure that the servo will move in the right direction when you flip the toggle switch!!!! If it doesn't, revers the polarity on the main battery pack or mount the servo on the other side of the box and flip the arm around. Another tip is to have the axis if rotation of the servo directly below the toggle switch. That ensures that the arm will pop out of the box nicely and hit the switch. Also if the servo moves too fast for your liking try 4.5v instead of 6v. Or you can put a 1W resistor in series with the motor. The resistance will depend on the servo bit try 20-40 ohms, that's just a guess. Also the battery box that I have has a switch built on it that proved to be useful when aligning the servo. Make sure that the micro switch in the bottom is secure. If it gets knocked aside and releases the servo will continue to move down and hit the box.

You have to mess with it alot and move stuff around before everything fits but once it does work it's really cool! Give it a nice stain and varnish, and do a nicer job than I did too.

Here is my crappy handrawn schematic:
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This is an easy project and even a novice and make it. I've dumbed down the schematic as best I could to make it seem like an appropriate project for beginners. I wanna see you guy make it! Or perhaps you've already made one? Post pics! Just post in the thread if you've got any questions.

-Tony
 





Joined
Oct 24, 2008
Messages
1,057
Points
48
Thanks peeps! :D


Yeah I've seen those too. Seeing all those vids inspired me to make my own. But my design is by far the simplest of any I've seen on the net. Some use the PIC microcontroller design. Others I've seen use a 555 timer to generate a signal that the servo can respond to. But in both cases the design is semi complicated and wouldn't be feasible to make for a novice to electronics. I've build more complicated projects in the past with PIC electronics, but for this simple toy I wanted to make it without going to Radio Shack or buying any parts online. It literally cost me nothing to make. All the parts I had lying around already. Plus mine is truly "off" when not in use. :san:

-Tony
 

Raybo

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Joined
Oct 30, 2008
Messages
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I love it! :beer:

+1 for...................?:thinking:

Ray
 
Joined
Oct 24, 2008
Messages
1,057
Points
48
Sorry, but without airflow this thing gonna die quick.

Not a chance. I've had it for months and flipped it hundreds of times. Standard servos don't get hot unless they encounter resistance. Just movement won't harm them at all. That's what they're made for.

-Tony
 




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