Soldering Instructions V2

These are Version 2 soldering instructions for our new green circuit boards.
If you have a blue circuit board, please use the instructions located here.

In order to assemble the Ultimate Useless Kit you will need a soldering iron, wire-cutter/strippers and a heatgun or lighter/matches for the heatshrink.

Our kit is very easy to solder together, it only has 11 electronic parts:

Parts list

Battery Pack
Gear Motor
Toggle Switch
Printed Circuit Board
Green & Red 3 mm LEDs
Two 56 Ohm Resistors
Hook-Up Wire
Heat Shrink

Soldering The Machine:

Soldering is so easy there’s a comic book instruction guide called Soldering is Easy that we recommend.  It was created by DIY guru Mitch Altman, Andie Nordgren & Jeff Keyzer.

If you have never soldered before we highly recommend that you read the above and/or get help from someone with experience before you assemble our kit.

Observe All Safety Precautions:  wear eye protection.  Don’t breath the fumes: work in a well ventilated area.  Do not touch the hot end of the soldering iron…

Tip:  Helping Hands  In the above photo you’ll see various ways of holding parts steady in order to solder them.  A PanaVise on the left is a great tool to own if you solder on a regular basis.

Do not go out and buy a PanaVise just for this project. Less expensive alligator-clip contraptions are available or you can macgyver one as shown in the above photo using pliers and a rubber band.

We don’t recommend using your real hand…

PCB Top & Bottom

Most of the components will be mounted on the Top-Side of the printed circuit board, with the exception of the LEDs.  Make sure you read the entire instructions before starting.

Step 1:Seat Toggle

Insert the toggle switch into the top-side of the circuit board as shown in the photo. 

It’s location is marked on the circuit board as “Toggle”.



Soldering Toggle

On the bottom side of the board, solder all 6 pins of the toggle switch.






Step 2:Insert Resistors

Insert the two resistors in locations R1 & R2 as shown in the photo.

Bend the wire leads of the resistors outward to help keep them in place while you solder them to the board.

Solder the Resistors

Solder the resistors to the board.

Clip off the excess leads using a pair of snippers, nippers or even finger-nail clippers.




Step 3:Insert the LEDs

The green and red LEDs (Light Emitting Diodes) look identical so we’ve marked the wire leads of the red LED with a red felt marker in order to differentiate them.

Insert the green LED in the location marked LED1.  The longer lead is the positive (+) one and should be inserted in the hole nearest the + symbol marked on the board.

The red LED goes in the LED2 location and the longer positive lead goes in the hole nearest the + symbol.

LED Detail

The green LED needs to stand off the board 2 millimeters as shown in the photo.

The red LED should be flush with the board.

Bend the wire leads of the LEDs outwards so they stay in place while you solder them from the top side of the board.


Bend Green LED

After soldering, carefully bend the green led as shown in the photo and then clip the excess leads from the LEDs.





Step 4:

Cut the hook-up wire into two pairs about 17 cm (6.5 inch) and 10 cm (4 inch) long.










Step 5:Microswitch

Split one end of shorter, 10cm pair of wires and strip back 1/2cm of insulation.

Cut the heat-shrink in two and slip them over the end of the wires as shown in the photo.  Make sure you keep the shrink away from the ends when are soldering; you don’t want to prematurely shrink them.

Solder the wires to the outside pins on the micro-switch.  The middle pin on the micro-switch is not used.

Now move the heat-shrink tubing over the end of the wires, and carefully apply heat using a heat gun or lighter.

Step 6:Microswitch to PCB

Split/strip the other end of the micro-switch wires and route them through the strain-relief holes. Solder the wires to the pads labeled Micro as shown in the photo.

Polarity does not matter, either wire can go in either pad.

Step 7:Battery Leads

The battery holder comes with its wire leads stripped and tinned.

Route the leads from the battery holder through the strain-relief holes of the board ensuring that the red wire goes to the Bat+ location & the black wire to the Bat- location.

Note: polarity matters, make sure the red and black wires are soldered to the correct pads.


Step 8:  Split/strip the ends of the 17cm hook-up wire pair.

You’ll note that the conductors are copper and silver colored which helps us install the motor wires with the correct polarity.Motor Wiring

As shown in the photo to the right, solder one end of the silver wire to the indicated pin on the motor.

The other end of the silver wire is soldered to pad on the board labeled Mot-.

Solder the copper colored wire to the the other tab on the motor.  It’s other end is soldered to the Mot+ pad on the circuit board.

Note that the wires are routed through the strain-relief holes in the board as well as through the clear plastic strap on the end of the motor.

Test The Circuit:

The above photos show how the circuit operates.

▪ When the toggle switch is flipped ON, the red LED is on and the motor turns counter-clockwise.

▪ When the toggle switch is flipped OFF, the green LED is on and the motor turns clockwise.

▪ Depressing the micro switch shuts power off to the whole circuit only when the toggle switch is in the OFF position.

You are now finished soldering the electronics!
Next step is to build the case & install the electronics assembly using these instructions.

4 thoughts on “Soldering Instructions V2

  1. Mark Burns

    Woooo Hoooo,
    It works, it works!!
    Assembled tonight just in time for anniversary with favorite squeeze.
    I know she’ll get it and love it.
    Just hoping she doesn’t come to the conclusion that I’m as ultimately useless as the great little machine.

  2. Bree Frost

    Wow. Turns out I can follow instructions. May need to practice my soldering though. The only other thing I’ve ever soldered before was a transformer onto and pcb in a sewing machine. That was a doddle in comparison.

  3. Yardboy

    Had a wonderful time building this with my 12-yr-old daughter. She did all the soldering herself and it was a perfect couple of hours of daddy-daughter time right at the end of her Christmas break from school.


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