Neopixel Candelabra
Introduction: Neopixel Candelabra
The project came about as a means of making use of something that was only partly used and making it more user friendly.
The Candelabra was mainly used as a feature candle holder as the candles were very rarely lit being both a consumable and a pollutant.
As a result of this it occurred to me that it could still function as a usable Candelabra but instead of wax candles I could use light rods.
The light rods would make use of total internal reflection in the same way that fibre optic cables use light to transfer data.
The light source would be provided by Neopixel RGB Mini LED's the light rods would be made of clear resin and the control for the LED's would be provided by a MicroBit microcontroller.
Supplies
Software
BlocksCAD
Cura
Makecode
Hardware
3D Printer
Micro:bit
USB cable
USB power adapter
Materials
2 part Epoxy Resin
22mm diameter poly tubing - (4 * 30cm lengths)
Lubricant to aid release of cured resin from moulds.
Epoxy resin polish
NeoPixel RGB Mini Button PCB - qty 4
22 Gauge enamelled copper wire or solid core coloured insulation wire.
26 Gauge Ribbon cable
2.54mm sockets, crimp or solder termination.
Right angle pin header strip
Copper strip board
Tools
Track cutter or 3.5mm drill bit
Soldering iron + Solder
Wire cutters
Long nose pliers
Saw
File or sanding paper
Step 1: Light Rod Adapter Design
In order to enable the Light Rod to be supported in the candle holder and at the same time allow the Neopixel to be mounted at the end of the rod to enable light to be efficiently coupled, an adapter was required.
This could be envisioned in various ways but in my case I decided to 3D print it.
The first step was to measure the candle holder and obtain the required dimensions.
The candle holder is essentially made up of 2 cylinders a 2cm x 1cm candle socket and a wider cylinder 3cm x 1.2cm wax catcher that sits above it.
Using BlocksCad I created these required elements to the measurements previously obtained.
The candle socket element would require a recess for the Neopixel and a way for the wire to be routed.
The wax catcher element would require a hole aligned to the element below it and a recess for the wire, which also serves to make up the slack in the socket for the light rod.
Step 2: Light Rod Adapter 3D Printing
Having created the elements these were then imported into Cura.
At this stage 4 pairs for a total of 8 elements were required and this is achieved with ctrl+M and specifying the number of copies.
The resulting gcode is then loaded in the 3D printer.
As the Candelabra has a golden finish I used Gold Silk PLA filament.
Printer settings for 4 pairs of adapters.
Layer quality - 0.15mm
Wall thickness - 1mm
Infill - Density; 50%,
Pattern; Concentric
Build Adhesion - Brim
No supports.
Weight - 37g
Filament length - 12.4m
Print Time - 4 hour 30 mins
Step 3: Light Rod Adapter Assembly
Having created the Light Rod Adapters these now require assembly including the Neopixel.
Looking at the pad configuration for the Neopixel it was evident that the two 5V pads were connected in series and likewise the two 0V pads too, in order that that these could be connected in a continuous series chain.
However, to simplify the connections in the adapter, I would connect these as a spur off the main trunk.
This would mean that only 4 wires would be required per Neopixel rather than 6 wires.
Be sure to colour code the wires if using enamelled copper with coloured paint or sleeves, alternatively solid core wire with coloured insulation could be used.
With wires attached a 90 degree bend was formed and the wire pushed through the hole to exit the bottom this was then bent back up by 180 degrees inline with the recess.
The wires were then fed through hole in the wax catcher element, bent 90 degrees across the top in the recess and then bent 90 degree down the side..
The 2 elements are now united, a dab of glue will hold the two elements together.
Taking a piece of stripboard measuring 3 holes wide by 7 holes long a length of right angled pin header strip consisting of 3 pins, is inserted and soldered in each end.
At hole co-ordinate 2,6 cut the copper track, either using a track cutter or 3.5mm drill bit. 134