This is my version of Glinda's Bubble Wand from the Wicked movie series. It's over 90cm (36") tall and includes LED's on the inside of the orb so that the “bubble” tips of the wand can light up. I made it for my wife for Halloween this year, basing the design on stills from the movie, however it's not 100% movie-accurate - mostly to accomodate 3D-printing constraints.
You can leave out the light module very easily and just print the wand. The wand stem screws together for simple assembly/disassembly. If you do print the light module, the orb can be opened with the custom wrench to turn the lights on and off. I printed the transparent parts of the wand using PCTG on a Bambu Galaxy Effect plate, but transparent PETG should work well too.
Please read the attached assembly guide if you intend to print and make one!
Printing & Design Notes
There is a full list of parts required (inluding links) in the assembly guide.
- I have left discussion of the electronics to the Light Module section.
- I like to optimise my parts for strength and to avoid supports where possible, hence why a lot of the parts are split.
- I used the vertices of a truncated icosahedron to position the wand tips on the orb – I wanted to avoid having the tips aligned in noticeable rows.
- I have included a STEP file with all of the printed parts should you wish to alter the design.
- Pink parts were printed in Siddament matte pink PETG, which is somewhat translucent.
- The finial was printed in grey Sunlu PLA+, in lieu of a more silver silk filament.
- The electronics parts were printed in some random transparent PLA I had.
- I printed the transparent parts of the wand using Siddament PCTG (as it’s the only transparent filament I have) on a Bambu Galaxy Effect plate for a smooth finish. Transparent PETG should work well too.
- You can see my settings for the PCTG if you download the standalone transparent parts 3MF. The settings are based on guides for “printing glass” that boil down to:
- 1 wall, 0 top and bottom shells, 100% infill all on the same direction
- Veeeeery slow
- Tuning flow rate. The default 0.95 leaves gaps between each extrusion width. I went as high as 1.10 and saw good clarity, but it led to over extrusion at corners (I didn’t get a chance to tweak pressure advance to compensate). In the project profile the flow rate is 1.00 to avoid issues with over extrusion. I printed most of my transparent parts at 1.06, but this caused quite a few issues with over extrusion leading to nozzle mess leading to other problems (burned blobs, layer shifts, detached parts).
- I was hoping the stem would be a bit more transparent but am OK with how it turned out. Printing the stem segments vertically may have looked better, but I was concerned about strength. I may try this out later.
Light Module Design
I designed the light module around a few constraints:
- Time – this being a Halloween prop, I started about a month ago, so was dependent on parts I could get quickly, or already had on hand. Also, I would love to have spent more time designing this assembly to optimise it for more even light coverage.
- Electronics – I can solder and know which end of a battery is which, but my electronics knowledge ends about there. I wanted the LEDs to “breathe” because I think static LEDs are boring. Luckily, I found a site that could ship a bunch of different parts to me quickly and for a reasonable cost (I’ve included links below). I trialled both integrated breathing LEDs, and the current external circuit (Yusijie 217). I went with the external circuit because it allowed me to use brighter LEDs than the integrated ones.
- Power source – This uses 12 LR44 coin cells in a combination of series and parallel. I had a bunch of LR44 coin cells lying around that I had ordered from eBay for cheap for my daughter’s various toys. It was easier to organise these into a workable package than trying to squeeze in AA or AAA batteries, or source and figure out how to wire and charge a LiPo pack (see: Time). We need three cells to achieve the required voltage to run the circuit and the LEDs. I figure each LR44 cell has about 100mAh capacity - with 4 columns of 3 there should be 400mAh total capacity. The 5 LEDs I am using have a max draw of 60mA, so we should be able to run this for at least an hour, although hopefully a bit longer with the “breathing” effect dimming the LEDs.
- Update - I have had the lights runnings for at least 2 hours and they seem as bright as ever, so this was probably overkill!
- The original plan was to use brass sheet as terminal plates for the batteries, but I ended up running with this solution which seems to work OK-ish.
- Size of the ORB. I would have preferred the orb to be smaller (maybe 60mm diameter instead of the current 80mm) but settled on this size because I wanted to leave myself some space and it was the first part I started with (see: Time point again).
- Needing to position everything fairly centrally in the ORB. Once the components were mapped out, I just designed parts around them to hold them in place and figured I’d work out the wiring once the parts were printed - hence why the wiring is so… freeform. I made some minor tweaks to the parts but I’m sure it would be possible to design a much better module. If you want to have a go yourself, the lower bayonet mounting part is fairly adaptable and would be a great starting point.
kieranrealist
