Magic power prop - Version 3

Felt inspired to revisit this prop idea recently to try improving on the previous versions, here are the results!

Version 3 notes:
- I am regarding this as another rough prototype; made do with basic tools I had at home and only briefly wet sanded the edges by hand - heating the plastic helped in smoothing / refining the edges a bit. Haven’t tried cutting PETG with a scroll saw, band saw, router or laser cutter but some/all of these might create more precise, clean cuts.

- This new LED pendant is easily pushed in and pulled out of the spiral form which holds it securely by tension. The pendant can be turned on and off without removing it by pressing the bottom of the pendant through the hole in the spiral. It features 3 programmed modes: always on and two flashing speeds. Various colours available. Bought it on ebay: www.ebay.com.au/itm/HOT-Pet-Do…

Also experimented with a few other LEDs which you may find useful:

www.ebay.com.au/itm/Great-Invi…

www.ebay.com.au/itm/Men-Women-…

www.ebay.com.au/itm/Popular-LE…

www.ebay.com.au/itm/Tea-Light-…

Haven't tried the flickering 'candle light' LED yet but I imagine that could be quite effective when reflected off the PETG!

- I initially tested Worbla’s TranspArt; it is more flexible but this design needed a sturdier plastic; also, this PETG has better clarity / clearer transparency. Also tried dyeing it with Jacquard iDye Poly but later abandoned that approach because I thought the light reflections were more effective on clear plastic - this approach is really dependent on darkness / low light settings, however.

- I was planning (and hoping) to use 1mm PETG for all of it but this thickness didn't seem sturdy enough for the band and spiral; I tried merging two layers but that seemed too messy. (Perhaps I should have altered the design to make it work). I already had some 2mm scraps at home so used those instead. Tried cutting the 2mm with a utility knife but gave up after struggling with it, was taking way too long (fresh blade) and was really hurting my hand so I cut it with tin snips instead - very slowly and only partially squeezing the handle with each snip to avoid cracking the plastic.

- Practising on scraps is absolutely essential to get a feel for shaping PETG and how much heat to apply; my first attempt was a mess; over-heated which caused bubbles to form and unintentionally merged some areas together. Also, keep in mind that the more the plastic is heated and pressure applied with hands the more likely it is that any texture on gloves will be pressed into the plastic.

- Removed a few minor scratches with Novus plastic polish #2 then applied #1 to help protect the PETG.

- SAFETY NOTICE: Wear heat-resistant gloves when heat-forming and work in a well ventilated area.


Photo annotations:

#1: Pattern pieces. Lower piece forms both the hand bracelet + spiral holder. Upper piece forms the warped shape that is connected to the top of the spiral. The warped area can be various shapes. The strip length will vary depending on hand size; a mock up will help in both working out this measurement and also later as a guide when heat-forming. I added a bit extra just in case then trimmed the excess after forming the spiral.

#2: Right: Original condition of the LED pendant. Left: Pendant disassembled and altered - the metal clip is easily removed when opening the plastic shell. To help diffuse the light I sanded both the LED itself and the plastic shell.

#3: Heat-forming process begins with the bracelet section. I bent the strip whilst holding it above my mock up from this angle / view. Test fitted it on my hand once it had cooled down enough to see how it was actually fitting my bare hand then made some further adjustments / refinements. The spiral is formed around the pendant shell then tightened for tension.

#4: Started the warped shape by forming a mini flattened spiral at the narrow end which connects onto the end of the main spiral, tension helping to keep it secure. Waited until this section had cooled down completely before forming the rest.

#5-8: Whilst forming the warped shape I tested it with the pendant underneath to see how the light was reflecting.


There's a few extra photos in my Flickr album: flic.kr/s/aHskw8qYMG

Filmed a brief video showing my hand rotating it around, changing the LED mode and taking the pendant out. Photographing this was an interesting challenge, recording a video was even more difficult and awkward. xD
youtu.be/Ay7otm4wPYY