Soldering Instructions Version 1

These instructions are for the original Version 1 Green Boards. If you have a Ver. 1.2 Blue Board please use the these Instructions.

Electronic Parts

In the Ultimate Useless Machine Kit you’ll find a motor, battery holder and a bag of parts containing a printed circuit board, toggle switch, microswitch, a resistor, red LED, green LED, hook-up wire, & heat shrink.

Apple Guy was kind enough to make a How-To-Video on soldering the Ultimate Useless Machine.


First cut the heat shrink into 4 pieces, and the wires into pairs of approximately 5 inches and 4 inches. Strip the ends of the wire about 1/8 inch.


Populate toggle & resistor




Now begin to populate the printed circuit board by inserting the resistor and the toggle switch.




Solder resistor and toggle




The leads on the resistor have been bent outwards to help keep it in place before soldering. Solder both the resistor and the pins on the toggle switch.

A PanaVise, or a regular vise make soldering the pcb much easier, but they aren’t necessary.




Clip the excess leads off the resistor.





Solder wires to motor



Solder the longer set of wires to the motor. The polarity of the motor wiring matters, so make sure the red and black wires are as shown in this photo.


Loop the wires through the clear plastic strap on the other side of the motor for strain relief and twist the pairs together.



Solder wires to microswitch



Solder the shorter pair of wires to the microswitch as shown. Polarity doesn’t matter for the microswitch, so red can be soldered to either pin, just make sure you don’t solder anything to the center pin: it’s unused.

An extra set of hands like this alligator-clip contraption is helpful.





solder wire to board

Click to Enlarge



Now insert the leads for the microswitch in the holes beside the toggle switch.

There is printing on the top side of the board labeled S1 and S3 and that’s where the wire go.

There’s no polarity to worry about so either wire can go in either position. Solder the microswitch’s wires to the circuit board.

The motor leads are polarized so make sure the red wire goes in the hole marked Mot+ and the black wire to Mot – .



Solder in battery holder leads

Click to Enlarge





Polarity matters on the battery holder as well. Solder the red and black wires in their respective locations on the board, marked Bat+ for red and Bat- for black, as show in the photo.

Like you did with the resistor’s leads, take your cutters and clip any excess wire poking up from the solder connections.






Click to Enlarge

Now to put batteries in the holder so you can test your work so far. Make sure you use fresh alkaline AA’s. Re-chargeable batteries just don’t supply enough current.

Once the batteries are installed the motor will begin spinning one direction and when you flip the toggle switch it causes the motor to reverse direction.

Here’s a photo of the everything finished and mounted to the bracket. You don’t have to mount anything yet, but this photo shows the direction the motor turns and how it stops when the micro switch is depressed. As well as the LED’s which you will install in a moment.

Activating the micro switch will stop the motor only if the toggle switch is “OFF”. When the toggle is “ON” the micro switch has no effect.


Click to Enlarge


Now we need to find out which LED is red and which is green. You can’t tell apart by looking at them, they appear identical so you will have to test them first.

You’ll notice that one of the leads on each LEDs is shorter than the other. This is to indicate polarity, with the short lead being the negative.

Click on the photo to the right to enlarge. Pay attention to the through-holes where the leads are being held.

Carefully touch the leads of the LED to the through-hole plating as shown in the photo.

Be careful not to touch the leads to any of the other pads or you may short out the LED.

The polarity of the LED matters and it will only light with the correct orientation. It won’t hurt the LED to be reversed, it just won’t light up. In fact, the LED’s will be wired in parallel to each other, but with reversed polarity.

The shorter lead on the LED in this photo is on the left. Also, in this photo the toggle is in the OFF position and even though I’m testing the red LED, the pads I’m contacting will be used for the green LED. Flip the toggle switch and and you can test the other set of through-holes if you like. The short lead will be on the right side for this set of holes.

Now remove the batteries.

Now that you know which LED is red, slip some heatshrink onto the leads and then carefully bend them as shown in the above photo. Note how the lower lead is shorter, it is important you get the polarity right.

Use a small pair of needle-nose pliers if you want to get nice sharp bends.

Do the same thing for the green LED, but make sure the shorter lead is on the top when you start bending.

Placement of green LED




As shown in this photo, the green LED is ready to solder. The shorter pin is on the left. The LED is soldered onto the bottom of the board.








LED Polarity


Here you see the both LEDs soldered in place. Click on the photo to enlarge it. Make sure the positive leads are on the outside, and the negative ones on the inside.

Now carefully solder the leads in place. Cut off the excess leads sticking out of the other side of the board.

You are now done. Proceed to final assembly instructions





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