As demonstrated in D1 of this series, LEDs and solid-state technology are changing more than general illumination. Other instances of applying near UV LEDs with emission to cure light-cure resin composites. We have applied this to replace Metal Halide light sources that require 20 minutes to start-up, and are skin frying monsters. LED cure lights are also more predictable and focus-able than natural light, and can be applied indoors, and less bulky and more powerful than fragile fluorescent cure systems. LED sourced cure lights are now used in printing, dentistry, and commercial production of resin-based composites. We are also applying this on small and large scale applications from the very small (like D1 SLA curing) to larger scale units for curing large objects, like fiberglass repair of boat hulls, custom automotive body panels, and low odor repair of fiberglass bathtubs and shower floors. The use of LEDs produces instant-on high intense light, with much less power, significantly less heat in the lighted pattern, less exposure to hot surfaces, and contain none of the damaging ultraviolet light that does nothing to enhance curing, but is harmful for operators. The use of UV initiated resins offer the advantage of extended shelf life as there is no catalyzed resin to harden in the container and less odor for use indoors. An update with new images and details will be posted here when available.
I found this little light on ebay at a lunch money price, so couldn’t resist. It started life as a Hamilton Industries (Chicago) lamp model 60, made in Japan in the early 1960’s. It used a 12V magnetic transformer and a resister to provide a dual level light control of its 20W signal lamp. The amount of light it put out was barely visible in the presence of any ambient light. Meanwhile, I had a cute little key-chain wireless remote controller for less than $14 from LED Supply that delivers PWM dimming and on-off control of 12VDC LED loads. I stripped the guts out of their kit and put them inside the base of the fixture. The little lighting head was about the right size for a 12V MR16 lamp, so rather than re-invent that wheel, I just retrofitted the head to take a bi-pin socket and planned to use a retrofit MR16 lamp to deliver the light I wanted. That ended up more of an issue than I expected. First, after testing of all the LED MR’s I had around, only one brand would operate and dim effectively when run on DC power. The rest were poor dimming on AC power, but on DC they were miserable. On the LED Supply remote dimming module, they were useless. The lamp I ended up with was a Philips Enduraled product, and it will dim down to around 10%.
The remote control is a bit of fun, as it has an antenna that works well with the antenna arm on the fixture, so they seemed a great match. I printed a holder for the face of the power supply (now control) enclosure at the base of the fixture to hold the remote, which makes it a simple panel controller when the remote feature is not needed. When the light is used to wash a wall or light art or some other function besides a desk lamp, the remote can be removed and control the fixture from across the room. The power supply is a simple 12VDC wall wart, while the base houses only the remote control electronics now.
The base looked in need of a bit of dressing up, so I printed a retro-turbo trim ring to surround the remote control mount on the SLA printer and painted it with VHT fake chrome to give it a sand-cast aluminum look. I also printed the same part on the FDM printer for comparison. I’m throwing in two images of the raw prints to show the difference in surface quality one gets between these machines. Obviously, for parts that include details that will be hard to sand and fill, the SLA process is superior. For parts that need to be strong and can be easily finished, the FDM is the go-to tool.
So, this little weak black egg ebay find has been transformed from a barely functional desk lamp novelty, to a bright, useful, remote controllable, dimmable, black egg turbo trimmed LED light novelty. I’m a fan of the 50’s and 60’s design aesthetic, so this one felt right and was fun to put together.
I am a task lighting fanatic. I use them everywhere, so am always looking for something new to add to my collection. In this installment, I am addressing the need for a light that is compact, delivers intense light (1,200+ Fc) with no glare or brightness, and high color accuracy. The application is pretty straightforward, from soldering station use where a magnifying glass is used, to fine detail work inside or on the outside of models. For good measure, I also wanted it to aim at the wall as a photo fill light, or straight up as am ambient fill light, and have a dimmer to allow me to set whatever level I want for the application in hand at the moment.
With all the practical specifications set out, I decided to let this design be expressive of the gadgetry involved. Let it all hang out. I also decided to incorporate the new Bridgelux Vero LED with its integrated Molex connector, and a Nuventix cooler, just to amp up the tech factor. This is where things got interesting. The Bridgelux array operates at 33.7V (500mA). The Nuventix cooler at 12V. I am powering the whole thing with a 24VDC wall wart power supply. That meant I needed to employ a boost driver for the LED and a buck (24VDC to 12VDC) power converter for the Nuventix cooler. I used Recom components to attain this, and used a cut up experimenters printed circuit board to connect these two to the power supply, the cooler, the LED and the dimmer control. That’s a lot of wires to find a path for, so I decided to leave them to roam free, let everyone see the components as well.
This is a style of design I personally enjoy, and have been doing since the 1980’s, where we made little 12V lamps with fiber optics, MR16s, halogen burners, or automotive headlamps, often suspended from structures made of building wire. In this case, the stand I found at a Goodwill. It was a table lamp, whose shade was gone, and socket was cracked. I liked the cast iron base and single post stand, so nabbed it for a dollar and tossed it in the pile with my other finds, waiting this moment to be put to service.
If you look at the head, the switch is a sliding action, on the left side of the head. Pull it forward to turn it on, push it back to shut it off. A hole in the side of the housing allows you to see the action inside. No, there is no reason for this, other than it seemed more appropriate than an off-shelf toggle or twist switch.
The light on the task surface is at 1,425 Fc, the LED is 3000K, 97CRI.
This weeks project is a concept model exploring an organic form of twisted and tapering ellipses. The height is 24″, and it measures roughly 3 1/2″ x 2 3/4″ at its base. The design is intentionally simple, utilizing a single LED strip concealed behind a valence to one edge. Total power at full brightness is 5 watts, and output is roughly 400 lumens total. The interior is covered with White Optic material to create a diffuse soft edged luminance from within. There is a simple stem dimmer control at the base circuited in series to the light strip, and a two position switch to the side providing full-on / off / dim settings. This model is powered by a wall-wart 24VDC power supply.
This was printed on a 3D printer, sanded smooth and painted matte white. In a production version casting the body in ceramic with a matte glaze would render a more finished end product. Low power LEDs don’t require much thermal management, can be circuited with on-board micro IC current control driver, creating a very simple to assemble and economic end product. Even in this plastic concept model form, the costs of the entire assembly were under $200, with the power supply.
While not particularly visible to everyone in the SSL universe, over the past few years one area of interest in LED product development for me has been in use of 405nm LED light sources to cure various plastics materials. The advantages are lower power requirements and reduced overall heat in the cure zone over conventional fluorescent or HID light sources. This has been of particular interest in curing fiberglass resins manufactured by Sunrez. The typical demand is for between 200 and 1,000 µW/CM² at 400-405nm wavelength. The use of LEDs allows us to generate exactly that without the waste of visible light, and longer wavelength power the resins are not reacting to. In one project, we were able to replace a 1,500W HID light source with a 120W LED light system that produced faster cure times with less than 10% of the total power, and virtually no heat added to the heat generated by the resin’s exothermic reaction to the curing initiator. Since then, we’ve built 405nm light cure fixtures ranging from 1,200W to 25W.
In this case, I needed to cure 3D prints we generate on a Form Labs 1+ 3D SLA printer, and do so in an office environment without exposing other materials and occupants to UVA light output. The material used in the print process is acrylic based, with chemistry that is photo-reactive to 405nm. The actual prints are made using a UV laser source. When the part is removed from the printer it is washed in alcohol (91% IPA), rested for a few hours to dry the alcohol off, then placed in this cure cube for an hour or more, depending on the thickness of the final component. The end result is a hard first surface for finish sanding or painting, if necessary, and a more rigid part as a whole (less flexible).
The cube utilizes a simple aluminum housing, with FDM 3D printed top and bottom covers. The top cover houses a single Recom 500mA driver, slide switch and wiring terminal block on a Tasca LED driver circuit board.
5mm 450nm LEDs with a FWHM distribution of 60º, 25 per side and top (125 total), operating at 20mA each, mounted to custom circuit boards sourced at Express PCB. Each board connects the LEDs in parallel, while the boards are connected in series, resulting in a 500mA, 15.4V circuit, totaling 7.7W. The boards and internal exposed surfaces inside the box were then covered with White Optics 98 matte material to increase total light energy and diffuse The light energy at 405nm is roughly 600 µW/CM².
The bottom surface includes a glass plate where the product sits in order to make any possible stickiness of a part from adhering to the White Optic material below.
The housing was powder coated matte black polyester to make clean up easy and the box look nice. The overall interior dimensions of the box are 1″ larger than the total build volume capacity of the printer itself (5 x 5 x 6.5), as any over-sizing is unnecessary. This produces an optimal match between the location of the LED sources and any part the printer can produce.
The Cube is powered by a remote plug mounted 24VDC power converter.
The operation of the box is simple enough. The box is lifted up, the part is set on the base, the box is set over the part, and the light is turned on by sliding the switch to the on position.
Simple and compact is the order of desktop manufacturing, and this fits that model perfectly.
Testing so far has shown the cube can cure raw resin from liquid to fully hardened in less than an hour, and strengthens prints in that time or less. The heat generated from this arrangement is so small, there is no chance of any part being warped or affected by the process, other than the desired results of becoming stronger.
For parts to be left unfinished, that are desired to be used over extended periods, we coat the finished parts in either acrylic or polyurethane UV inhibiting clear coat, gloss or matte. This stops ambient room light or daylight exposure from making the parts brittle over time. I am building a second copy of this cube for completing extended testing of samples of the materials we are using to verify clear coat effectiveness, behavior of the print material over long exposure periods, and the behavior of these low cost LEDs over time. A commercial version of this cube could be made using more robust LEDs, but the costs would be significantly higher as well. In the current configuration, the LEDs only cost $0.60 each, so should they last a couple of years in use, replacement of the populated boards is a simple task, while the cost of higher power LEDs would have increased the cost of the entire end-product by as much as three times.
There is also an additional version of this same approach in using Red/Blue light sources for use in plant seedling starts. We’ve found tests with common rye and barley grasses, the time from germination to hearty growth ready for planting is accelerated significantly. Using an enclosure like this allows the plants to be exposed to intense light for extended periods of time (18 hours or more) without polluting the surrounding environment with the ugly light, just as the enclosed cube protects room occupants from exposure the the UVA light. In either case, the cube can be used in any room environment comfortably and safely.
So this gets us off the ground and is D1 of 52 in the series. As I’ve noted at the start, this is an exercise in making progress, and putting SSL to work. This is not a particularly exciting product in and of itself, but it is one that will be used regularly, which more than makes up for its lack of marketing sizzle for the masses – at least in my book.
The concept of pursuing another round of 52 designs in 52 weeks was the original intent for this series. However, the time involved was not available, nor were we able to rationalize the costs involved. The work of the 52/52 2010 was a significant effort, that never truly delivered an ROI, either directly or indirectly. It was a lot of fun and reflected my exploration of SSL technology on a fast track. I’d hoped to attract others in playing along this time around. This never materialized. Faced with going it solo again, I came to the realization I just couldn’t get it done, so abandoned the project. It is a serious disapointment, but did free me the time to refocus on our business and move us into a larger and more productive state and facility, so not all was lost. The original 52/52 designation for the projects has been re-titled YOL, for the Year of Light. Yes, it is a bit of revisionist history, but its my blog and I have that right.. literally and figuratively.
With that in mind, I am still sharing projects being worked on within Lumenique that are exploratory, experimental, or customer project related (when we are allowed).
I combine work with solid-state light sources with another emerging and revolutionary technology we started working with in 2010 – 3D printing technologies. I now have (3) such printers on hand, including a commercial FDM printer, a desktop FFM printer, and a desktop SLA printer. With these, we can now make translucent and transparent prints, including simple optics, flexible parts, and smaller, highly detailed components and mold patterns for casting in metal and urethane. I’m anxious to put these to work in creating interesting final forms. I’ll also be firing up the glass kiln a few times, and hammering out a few pieces in the blacksmith shop to keep things interesting.
In the next few days, I will be posting my first entry to start the ball rolling with something for my shop, that others in the 3D print business may find useful.
That all said, I hope that 2015 has been a great year for everyone!
I thought a lot about what to focus on in 2012 for this series, and decided that I had plenty to share from regular activities of Lumenique, LLC and Tasca. So, the plan is to select something completed in each of the 12 months of 2012 and feature them here. This will generally be products or projects completed for customers, but may also include a report on research work in process, when it adds value.
January Feature – TASCA Renovar Floor Lamp
This is a refitting of a Dazor table lamp, applying the TASCA lighting head, and adding an extension stand to convert a desk lamp to a floor lamp. The product was commissioned by a customer who provided the table lamp, purchased used. From the GSA and other government markings present on the original, it was obviously from a government facility. The table lamp made by Dazor has been around since the late 1930’s, where the fluorescent lamp version graced the GE display at the Worlds Fair.
ArchLED’11 will be marked as the official coming out for Tasca, my work lighting product offering. We presented examples of the base Uno line, as well as several Renovar and one Accent light. If you are wondering what these are, and are curious to learn more, you can visit the Tasca web site now. The sitre is fully populated with pictures and a specification download at:
While I do not intend to make this blog a commercial site promoting products and pitching our offerings, I do need to make a living, so there will be occasional updates to share where we are and what we are doing in this regard. This is how we pay for the fun side of being in the business, and afford the time to invest and share with others information on solid-state lighting.
A Little More on Tasca
Tasca is primarily focused on the work environment. Whether this is a machine operation, an assembly work station, an inspection station, or administration workplace, my intent is to offer the most effective light for enhancing visual performance with a durable product. I’ve invested decades experimenting with task lighting. My personal approach has been to lower ambient surrounding light levels to the minimum required to support the low acuity activities in the space, supplemented by localized task lighting to enhance visual performance in critical work areas. I have applied this in lighting designs over the last 30 years to reduce energy consumption, and live under it on a daily basis. In other words, I am passionate about this approach and believe it is a superior approach to achieve high visual performance. I strongly believe we are over-lighting our work spaces to some compromised light level, which is too high for ambient requirements and too low for effective task performance.
Over the last few years, the idea of creating a work light for hard service environments, bringing the advantages of SSL technology to work spaces that require high visual performance to support safe, accurate, and efficient work tasks. For over a year now I have been investing considerable time building a product I feel satisfies the demands of work environments, with an efficient product that will survive harsh environments. Tasca is the product of this effort, and just the beginning of a larger effort to produce desirable performance SSL lighting products for niche work space demands. We’ve already provided customized versions of Tasca for UV curing applications, and will be releasing specialty products, such as a 98CRI sourced heads for color critical inspection (like printing presses, millwork, textile and paint inspection), as well as a unique welding light that will bring welders vision of their welding field that has never been possible before.
Tasca is also founded on the concept of sustainability from durable products that are recycled either by dismantling, rebuilding, or re-purposing at the end of service life, not just thrown away. Unlike products that are filled with potting materials and irreversible assembly techniques that make recycling too expensive to be practical, Tasca fixtures are heavy duty assemblies designed to be reworked, rebuilt, or dismantled easily for recycling of materials content, separate of the electronics components that must go through a separate recycling channel. This includes the use of glass for the lens cover, which can survive decades of use, or be recycled easily through existing waste management channels economically. The Renovar and Accent line take all of this one step further by harvesting old task lights for their arms, refinishing the devices, recycling the old lighting heads, and converting them to Tasca lights by adapting our lighting heads, before a complete refinish and refurbishing.We will also refit your existing task lights, bringing old favorites back to life by bringing them up to date, or through Accent, create a custom design to suit your specific taste.
This is just the start of a great deal more to come. Sort of pulling the plug out of a dyke and letting things flow. This is an exciting niche opportunity for me, where I can add value through design integration assistance, and provide customization to suit unique customer needs. Unlike imports which must be marketed in large batches of off-shelf products to move production inventories – Tasca is made here in the USA, to order, to meet individual customer needs – even if that means building something completely new and unique that has a total customer market of one.
Okay, so I couldn’t resist. When I posted designs 49 and 50 last week, I received a note from Kevin Dowling (of CK fame), who also has an old South Bend lathe. He made a comment about a technique called “cloudy day” lighting, where shadows and highlights are removed in a viewing chamber for seeing detail on specular materials. The concept was that this might work as an aide for reading drill bits, which often have very small letters, laser etched on the cylindrical surface. I was intrigued, so created this small gadget.
This is a small chamber with concealed LEDs (Cree XRE’s) at the sides behind shields. The interior is lined with White Optics material to produce indirect light around the subject. It is powered by a 9V battery, with a simple momentary pushbutton switch. It will accept objects up to 3/4″ in diameter. To enhance vision I have added a 1.5X lens at the view window. The combination of bright indirect light and optical enlargement makes reading small drill bits, mill tools, and markings on the side of thin wires significantly easier. I have also found it works very well in viewing the condition of lathe cutting tools, which often look and feel sharp, but aren’t. Looking at them in this viewer reveals flaws impossible to see otherwise. This can also be used to thread needles, read a thermometer of a sick kid, and other surfaces that will fit through the port.
While this is not a perfect cloudy day viewing system, as it does not completely eliminate the dark stripe one sees on cylindrical surfaces due to the opening window, the fault is minor, and does not detract from the significant improvement it offers overall. It also costs a LOT less.