Balanced Lighting

Table lamps come in all shapes sizes and styles to suit a variety of purposes.

So in deciding to make one a conscious effort was made to explore a different style whilst adjustability was still a requirement.

The head of the lamp would be in the form of an adjustable flower with a glow disc and adjustable shield.

Taking inspiration from the human body and more specifically the hip joint for the main articulating element.

However, the realisation would be a little different.

This would take the form of a monostatic object in this case a sphere were one hemishpere is weighted.

At first glance this gives uncontrolled positioning with the light at the end of a long arm light that defeats the desired adjustability however, if we mount the ball in a raised hollow cylinder (akin to a truncated socket); coupled with a surface that is not too smooth. The ball can be repositioned and retain its position.

Therefore major manipulation can be carried out by repositioning the ball with smaller adjustments made at the head.

Whilst the weighted ball counterbalances the head containing the light source it also contains the control element in the form of a Plasma 2040.

Neopixels RGBW - Qty 12

Plasma 2040

Rotary Encoder EC11

Enamelled Copper Wire (ECW) - 0.4mm dia. (26 AWG)

Enamelled Copper Wire (ECW) - 0.75mm dia. (21 AWG)

Clear Acrylic Disc 120 mm x 1 mm

Self tapping screws M2 x 12mm - Qty 12

Self tapping screws M2 x 8mm - Qty 7

Self tapping screws M2 x 6mm - Qty 12

Bolt M4 x 20 mm

Bolts M4 x 10 mm - Qty 2

Bolts M3 x 6mm - Qty 4

Hex pillar M3 x 10 mm

Hex pillar M3 X 5mm - Qty 2

Filament PLA - White

Filament PLA - Orange/Yellow

Filament PLA - Grey

Stainless Steel hollow tube 34cm x 6mm dia.

Standoff M3 x 10mm(L) x 5mm(dia) [chrome plated] - Qty 2

Multicore flexible wire - 3 x ~50cm lengths

Heat shrink sleeving

Right Angle Panel mounted USB Extension cable (25cm)

Right angle pin headers SIL (18 (13 + 5) pins)

Capacitor 1000uF/6v3

Resistor 470R

Jumpers F/F - Qty 5

Ready Mix Concrete ~550g

May prove more cost effective to buy a range of values rather than individual values unless you already have them available. Some components may also have a MOL greater than the quantity specified in the component list.

Tools

2mm drill bit

3mm drill bit

6mm drill bit

Drill

Saw

Pliers

Wire cutters

Soldering Iron

Solder

Sanding paper

Screwdrivers

Needle files

Know your tools and follow the recommended operational procedures and be sure to wear the appropriate PPE.

No affiliation to any of the suppliers used in this project, feel free to use your preferred suppliers and substitute the elements were appropriate to your own preference or subject to supply.

Links valid at the time of publication.

All the 3D printed parts were designed in BlocksCAD

These consist of the following elements.

1: Rear petals.

2: Front petals with integral shield and control knob.

3: Middle petals with LED's and head adjuster. (2 x parts)

4: Support Grid

5: Hollow ball. (2 x hemispheres)

6: Base.

7: Stalk support (3 x parts)

A hemishpere with only the stalk hole is also included to enable the repositioning or accomodation of a different encoder subject to personal preference or the inability to source the encoder specified.

All elements were printer with the following settings.

1: Layer Height - 0.15mm

2: Infill - 100%

3: Base Adhesion - Skirt.

Some post processing in the form of filing and sanding may be required subject to print quality to remove strings or blobs that may be obscuring holes or result in uneven surfaces.

The circuit consists of 12 Neopixel (SK6812), LED's wired in a ring configuration which is connected to the Plasma 2040 at the screw terminals. 5V to 5V, 0V to -Ve, DA to Din.

The EC11 rotary encoder is connect to the Plasma 2040, VCC to 5V, GND to GND, A to A0, B to A1, C to A2.

Right angle pin headers are used on the EC11 and the Plasma. These are mounted at the back parallel to the back.

All the connections from the EC11 and the Plasma are made using push fit jumpers.

The code is written in Micropython v1.19

There is only one external control element connected to the microcontroller, this being the rotary encoder.

The rotary encoder operates both the colours and the intensity of the selected colour.

Colours: None, Red, Orange, Yellow, Green, Blue, Indigo, Violet, White

Intensity: Off, 12.5, 25, 37.5, 50, 62.5, 75, 87.5, 100 %

The selection is accomplished with the rotary encoder & integrated button using GPIO IRQ Handlers.

Sit the hemisphere on the base for stability.

The pole support is made up of three 3d printed elements which are stacked on each other. These can be glued or slid over a straw to keep them in place. The rings help to anchor the supports in place when surrounded by cement.

Stick or stand the support in the bottom centre of the hemisphere.

The cement ballast requires ~550g of cement this can be acheived by weighing or simply a generous (some overfill), scooping the cement into the hemisphere.

The hemisphere is filled with the cement, the consistency of which should be damp such that you can squeeze it in your hand and that it holds its shape when released. The removes the need to seal the hemisphere to prevent leakage.

Put the mix into the hemisphere and pack down firmly.

Ensure the pole support is centred and the top ring is just above the surface ~1mm and smooth the cement level with the top of the hemisphere.

Now set aside in a warm location to dry (as the cement can only dry from the top), it may take a little longer to dry and in doing so, salts may develop on the surface. Remove this with a dry stiff brush. The process of drying and brushing may need repeating a number of times until the salts no longer appear. This may take a few days in a warm room, longer in a cooler environment.

Press each of the Neopixels into the round cavities in the petals.

Due to variations in the PCB edge finish it may be required to file the edges of the LED's to get them to fit flush in the cavity.

The LED's are orientated DIn towards the centre and Dout towards the outer edge, 5V on the left and GND on the right.

Using the 21 AWG ECW create two separate rings using the grooves to contour the wire, one ring in the inner groove and one in the outer groove.

Trim the ends of each ring such that they butt together and remove the enamel, solder the ends together,

These rings will be used to provide power, one for +5V and the other for 0V and removing any cumulative volt drops as the LED's are no longer serially powered. The only serial connections are Din to Dout from each LED.

On each of the two rings opposite an LED, remove a small section of enamel and tin with solder, connect wires from these points to the LED's ensuring to connect the wires to the correct supply line.

Using 26 AWG ECW connect Dout to Din on each LED, to connect all 12 serially using the inner two grooves.

Three flexible wires ~80mm in length are now required to connect the supply and the Din line.

Using flexible multistrand wire connect a wire to the first designated LED in the chain at Din.

Using the same flexible wire connect one to a point on the 0V ring and another wire on the 5V ring.

Solder or crimp a 3 pin connector on the end on these wires, ensure the correct types are fitted to match with corresponding connectors on both the flower and the long wires.

Test the LED's to ensure there are no issues prior to full assembly.

Drill 12 x 2mm holes around a 45mm radius into the Acrylic clear disc which align with the outer holes of the petal element containing the LED's

The petal elements can be used as templates for hole alignment and held in place whilst the hole positions are marked prior to drilling.

The flower is constructed as a stack held together by a set of 12 screws which are all inserted from the front and through to the back. The shield also pivots on these screws to allow the light to be shielded to create a mood light.

Position the back petal element with the standoffs facing upward.

Align the middle petal element with the LED front facing upward and the outer holes aligned with the back petal element.

Place the glow disc over the middle petal and align the holes on the disc with the outer holes on the middle petal element.

Align the front petal element over the glow disc and align the slots with the hole.

Fit the 12 x M2 x 12mm self tapping screws through the slot and into the aligned holes and tighted until the screw head only lightly touches the front petal element. There should be some play between the front petal element and the screw head this will allow the front petal element to rotate freely from left to right, revealing or obscuring the LED's.

The stalk is made up of a hollow stainless steel tube 34cm (L) x 6mm dia.

It's not recommended to increase the length beyond this as it will compremise the stability of the structure.

Prepare a chrome plated M3 x 10mm hollow standoff by filing the edges on one end to create a shallow taper.

(The chrome plated M3 standoffs were a little wider for a snug fit compared to the non plated brass standoff, this may simply be down to supplier variations).

The taper is to allow the standoff to just fit into the inner edge of the steel tube without falling out.

Into the other end of the steel tube insert a bolt or nail with a flat head that overlaps the tube circumference.

Hold the tube on end with the standoff facing downwards and place it on the flat top surface of a vice or wooden block. Lightly tap the bolt/nail head with a hammer to drive the standoff into the tube.

The inserted stand off now serves two purposes, to allow the 3 wires to drive the LED's to be passed through and to enable the screw to be tightend to hold the flower head in place without damaging the tube.

Remove the nut/nail from the other end and insert this end into the pillar support on the hemispherical base.

Make a mark on the tube 10mm above the top of the tube support and at this point drill a 3mm hole and deburr the edges with a round needle file.

Twist the 3 lengths of multistrand wire together and thread down through the hole in the standoff and out through the 3mm hole in the side.

Slide the heat shrink sleeving over both ends of the wire and slide into the standoff and at the other end slide into the 3mm hole which will protect the wire from chafing.

Strip the wires and fit a SIL connector to the bottom end, ensure the correct types are fitted to match with corresponding connectors on both the flower and the microcontroller.

The grid supports the microcontroller and the USB interface cable and is held in place with a M4 x 20mm bolt that also holds the stalk in place.

Without the stalk in place position the centre of the grid over the support pillar and fit the M4 bolt in the hole in the grid that lines up with a hole in the support pillar. Tighten the screw just enough to hold the grid in place.

Attach the microcontroller with 3 x M2 x 8mm screws positioned over to the right on the delta supports. This is to ensure the right angle USB plug does not catch on the upper hemisphere. Similarly with the LED strip terminals.

A straight USB plug could be used if it does not protude out too far, preventing the top hemisphere from closing whilst a less bulky USB plug would allow the microcontroller to be fitted centrally, the delta supports have three pairs of holes to allow repositioning.

The other end of the USB extension is a socket which is mounted internally on a retainer and held in place with 4 x M2 x 8mm screws.

Insert the stalk into the support and connect the wire to the microcontroller.

Carefully tighten the M3 bolt to hold the stalk in place, being careful not to overtighten bolt which in doing so could crush the stalk.

Through the upper hemisphere thread the wires eminating from the top of the stalk and lower it down the stalk part way.

Fit two M3 X 5mm standoffs to the rotary encoder.

Lower the upper hemisphere down to allow the encoder spindle to fit through the centre hole and align the standoff with the two holes. Attach the encoder to the hemisphere with 2 x M3 x 6mm screws and fit the knob on the spindle.

Align the back of the hemisphere with the USB socket and fix in place with 2 x M3 X 6mm screws.

The sphere is held together with 12 x M2 x 6mm self tapping screws around the circumference.

The sphere minus the flower in this state is self righting.

Holding the articulated joint attached to the back of the flower head horizontally, thread the wire through the hole above the wide opening and lower the joint onto the stalk, feed the wire down through the hole in front.

Fit the articulated joint to the stalk with a M4 x 10mm bolt.

Strip the wires and fit a SIL connector to this end, ensure the correct types are fitted to match with corresponding connectors on both the flower and the wire from the microcontroller. Join the connectors on the wire and the flower head.

The bottom hemisphere sits in the base ring and allows you to position the ball in a number of different positions to direct the light as required.

The base itself should sit on a flat non slip surface to prevent movement as the ball is positioned.

The inner rim of the base as printed will likely be a little slippery to support the light at a very acute angle and subject to the surface finish of the filament used.

The join between the two hemispheres in conjunction with the base serves to prevent the angle of the lamp stalk exceeding 55 degrees.

Stick a ring of non slip matting or similar material on the inner support rim of the base.

Sit the base on a non siip mat, if the surface it will sit on is slippery.

Insert the USB lead into the socket at the back and insert into a compatible adapter.

Position the circular base in a suitable location and sit the ball on top.

There is no separate on/off switch everything is controlled by the encoder.

Main adjustment is accomplished by positioning the ball on the base, small adjustments are made by tilting the flower head.

The start up default is all LED's off.

Turn the button left or right to step through the colours, stop turning when the required colour is visible.

The LED's can also be turned off in this mode by rotation of the control.

Press the button to change to intensity mode.

(Default intensity mode is 100%)

Turn the button left or right to adjust the intensity, stop turning when the required intensity is achieved.

Press the button to return to colour setting mode.

The Intensity setting will be applied to all the colours in this mode unless it is subsequently changed.

Until the next time, thanks for reading.