This is actually dedicated to my girlfriend.
Little Machine that creates soap bubbles, driven by a battery, a motor and a little fan.
It features two different kinds of gear transmissions (total 162:1) which drive a rotor with blow-out holes. The rotor immerses first through a bath with soap on its lower half to build the soap-membrane in its holes. On the upper half of the rotor the fan should blow out the membrane to a bubble.
The aim is actually less functionality than being an DIY-eye-catcher: it was designed for acryl-cut and to be home build with very few different materials.
One word ahead: it does not fully work yet. The gearbox and transmission works, the rotor rotates through the soap-bath and when manually blowing, you can produce bubbles yourself. But i underestimated the airflow of the fan: either it's too weak to extrude the Bubble, or to strong and will destroy the soap membrane.
Bill of material:
- You can either print or get the parts laser cut form the nearby digital workshop. 5mm thickness should be fine.
- Get yourself a little motor (for the gearbox) and a fan, and of course a matching power source.
- We used threaded bars (M3) as axis and countersunk bolts (M4) for the planet wheel attachment.
- Enough matching nut bolts. The design assumes 7mm diameter nuts for the axis/wheel rotation-transmission.
- Unfortunately we didn't have any ball bearings so we used brass pipe pieces where the axis will be placed.
- Some glue that works with your material, e.g. Acryl-glue and Locktight or similar metal-glue
How to build:
- Glue the basin/bath together. Note the little holes, a little nail into them will make sure they fit tight.
- Glue the annulus (ring with inward teeth) to the annulus holder. Take care that the tooth don't get too much glue between them, otherwise the planets won't turn smoothly.
- Glue the first transmission cogwheels together (10 tooth next to 30 tooth)
- Glue the motor driver wheel (10 teeth) on to the motor axis. Hotglue has proven itself to be quite useful for this.
- Drill matching sink holes into the planet wheels (20 teeth) so the countersunk bolts will fit neatly into the cogwheel.
- Attach the two planet holders with nut bolts to the countersunk bolts from the planets.
- Frontaxis: Screw two nuts at the end of this axis, glue them and stick it into the planet- and fan-holder. Screw another screw where the rotor goes but donâ€™t forget to stick the fan holder between.
- Backaxis: also screw two nuts at the end of the axis and glue them. Attach the sun wheel to this end and stick the other end through the annulus holder. On the other side of the annulus holder also screw two nuts almost tight to the holder. Glue these screws and stick the 30-tooth wheel over them.
- Helperaxis: screw and glue one nut with some space to one end of this axis. Make sure the spare space does fit into the annulus holder but does not stick out the other side where the planets will rotate.
- Attach the transition wheels to the back- and helper-axis so the 10tooth will fit into the 30tooth wheels.
- stick the motor-holder to the end and rotate the outermost wheel. The transition should already work up to the sun.
- Glue or somehow else fixate the motor holder and annulus holder into a fixed and working distance.
- Stick the planet wheel/holder assembly into the annulus/sun. Make sure it's tight and will actually turn.
- Stick the fan-holder over the front axis and also somehow fix it.
- Attach the bath and rotor to the front and the fan and motor to their holders.
- Give it a try.
Things to fix:
- Fixating the whole assembly: for now we use simple Acryl-bars and glue the vertical parts to the horizontal bars. Unfortunately once glued it's fixed and you have no chance of doing maintenance to it.
- Motor and fan mount: while cable straps work fine for the fan, the motor must be fixed more tightly and should not move out of position like it does now. The design should provide a possibility to use any size of motor.
- The distance of the fan to the rotor should be adjustable. Again, once the whole thing is glued you can't alter this anymore.
Not even thoughts made about:
- Consistency of the soap-water. For now i just used the fluid from children-bubble-toys and have no recommendation yet for the best bubbling soap mixture.
- Adjustable gear ratio: although it might be possible to just add/remove the back-gears in order to provide different ratio for motors with different RPMs, this has not been tested yet.
- A further axis to mount DIY fan blades to the same gearbox, making the whole thing running from one single motor. Also open how to DIY some ventilator-blades. Rasping and flexing?
Credits go to:
- jonducrou for his Planetary OpenSCAD model (thing 16897).
- yzorg for helping me assemble the first two real units.
- my girlfriend Martina for being my patient and loving darling.
cheers & have fun