Adding a 3.5mm Jack Port to a Bubble Machine

I've added a 3.5mm switch port to a commonly available bubble machine without losing the ability to use normally. This means that the frog can be controlled by a child with complex needs to interact with the environment, see the bubbles through the use of a 3.5mm switch.

This modification still allows the bubble machine to be used without a switch as the soldered connection doesn't disable the original switch. It does require basic soldering skills.

I've assumed that anyone checking my projects out may want to get more actively involved so I'll include basic options for tools and supplies plus a more advanced option. See how you feel.

Children's bubble machine like this here or here

Good soldering iron starter kit - available here

or a more advanced soldering station with holder that I'm using here

Lead free solder (smaller packs are available) here

3.5mm mono jack socket available here

Drill - here

6mm drill bit - here

Signal wire - two lengths as you see fit (I used about 10cm for each here but it could have been longer to make it easier) I've used white here but feel free to use whatever colour you prefer - here

Wire strippers (I use these as they take the work out of wire sizing) - here

Wire cutters - here

#1 Philips head bladed screw driver - here or hardware shop of choice

AA batteries - this is a 20 pack which has balanced price and performance

These links are only suggestions for these supplies mind. I have included a few affiliate links for some supplies but only because they are cheap and effective supplies.

To open the bubble machine look for the Philips head screws and unscrew them all. Once you have opened the bubble machine case you can see the internals.

Gently pull the fan & motor surround to release it from the case taking care not to put too much pressure on the wires.

Using the screwdriver, unscrew the screws to release the motor surround from the red piece, and then unscrew the screws connecting the sides of the motor surround. Note the cut out at the bottom where the wires pass through. - we will be passing an extra wire through this area.

We will be making a jack switch to solder between the red battery point and the red motor connection to allow use of the bubble machine without an external switch.

Note: the motor has an orientation with mounts and support padding.

For this I've soldered a length of signal wire to the normally open contacts of the 3.5mm jack socket. Normally open means that pressing the switch closes the connection to make it - that's what we want.

You can confirm this with the continuity setting on a multi-meter, or if you've bought the mono jacks from the link above - it's these tabs shown.

Mark locate a suitable position for the 3.5mm jack socket. The position needs to be clear of the fan mechanism so take your time to get this correct.

Using the drill and the 6mm drill bit, make the hole for the jack. I propped the casing on a piece of wood to give the drill something to press into. I added a chamfer to the inside of the hole with a countersink bit but a deburr tool or a gentle scrape to remove any burrs.

I added the wired up 3.5mm jack socket to allow me to check the fit of the assembly and make sure it was clear of the where the fan housing would be. It looked good so I fitted the external nut and tightened it to hole the socket in place.

The fun bit.

Take care not to heat the tabs were soldering onto too much as this could damage the motor or battery connection.

I soldered one wire from the 3.5mm jack socket to the red motor tab then soldered the other wire to the red contact on the battery case.

Carefully place the motor surround around the motor, making sure no wires are trapped by the surround and screw together then onto the red piece.

Align and slot the fan and motor assembly into the case, check to ensure the tabs are positioned correctly. The completed assembly should look as shown.

When you're happy with how everything fits into the case - add the side and screw into position.

Add 4x AA batteries to test using the normal switch. If it works - great, if not - check the wire and solder connections at the battery and motor tabs.

Then use a 3.5mm jack button (see my other Instructables for how to build one of these if you don't have one to hand, it's here) - if it works, celebrate with a victory lap and a nice cup of tea.

If it doesn't work now - definitely check those solder connections.