"You turn it on, it turns itself back off. Truly no point at all."
This Instructable will walk you through how to make your very own Useless Machine!
This particular useless machine was created as a final project for Modeling and Control at Olin College of Engineering by Charlie Mouton and Meg McCauley.
We followed the instructions of Brett Coulthard as a basis for our machine.
Step 1: Aquire Materials.
- Single pull, single throw lever switch
- Double pull, double throw toggle switch
- Solder-less breadboard
- High torque motor
- 6 volt battery pack
The switches can be commonly found at any electronics store. For the lever switch, make sure that you get one that is on when you press it. This is referred to as a normally closed or n.c. switch. For the toggle switch, make sure you get one that stays on when it is switched, as this is an integral part of the machine. This means do not buy a momentary switch, which are typically designated by the symbol ().
Using a solder-less breadboard is a pretty common way to build a prototype of a circuit. These are also readily available online or at any electronics store. The dimensions of the one we used are 6.5 ''x 2.125''.
The motor is the part you have to be the most careful selecting. You need to make sure that it has a high enough torque, an RPM of ~50, and is compatible to run on 6 volts. We used Vigor Precision LTD BO8 motor.
Any combination of batteries that will provide you with 6 volts will do. We used a battery pack that took four AA batteries.
Step 2: Create a Box.
We determined the measurements by looking at the dimensions of our circuit board, which was the biggest part that had to fit inside our box.
Some things to keep in mind when you are building your box:
- You will want to be able to access the circuit and other components when you put it in, so consider only building two of the four sides.
- You will need a hole on the top side of the box for the toggle switch to stick out.
For our second iteration, we plan to cut the pieces out of delrin plastic to make for a classier looking prototype. We will update the Instructable when the second iteration is complete to showcase this.
Step 3: Check the Setup.
Before you continue, you should make sure that your box setup allows enough space for everything to fit inside your box and that the placement of the finger allows the finger to actually hit the switch. Every box's geometry is going to be a little different so it's important that you make sure that you confirm the placement of your materials before you continue.
We used two different methods to confirm that our placement would in fact work.
The first method is that we traced each of the components on paper and made a two-dimensional model. This allowed us to put the finger in the proper location to hit the switch.
The second method is that we used SolidWorks CAD to build a physical three-dimensional representation of our model. This allowed us to be confident that the components would not interfere with each other in any plane.
No we are ready to...
Step 4: Build a Circuit!
Here is our circuit diagram, as built in the National Instruments software MultiSim.
VCC is our power source, in this case, our 6 volt battery pack. The first two switches, S1 and S2, represent the toggle switch. The last switch, S3, represents the lever switch. Disregard the far right grounded wire on this switch. The motor is designated by the circle with the M inside of it, marked K on this diagram.
Make sure the wires are long enough. Remember, your toggle switch has to stick out the top of the box.
Step 5: Putting It All Together.
Using the design of your traced components put it all together!
We ended up having to mount our motor on some pieces of foam to make sure that the finger was high enough in the box.
Congratulations, you have successfully build your very own Useless Machine!!
We'll update this page soon to show you our second iteration!
Check out our working prototype!!