Having settled on the design for the hardware that would be made available on Ebay (the lamp module), the next task was to design some lamps that would be made available as free .stl file downloads via Thingiverse. The goals here were to provide some functional and (at least reasonably) attractive designs that would not take too long to print. I kept the maximum size of any piece to 6″ and designed around PLA filament printed with no  supports so these would print on the widest variety of printers.

This process started with a design for a ring to mount the LED module to and a corresponding clip that would be part of a lampshade that the ring with mounted LED would clip into. The 3D designs were done in a combination of 123D Design and Tinkercad.

The ring/clip combination took a considerable time to develop, given the heat generating capabilities of the LED module and the low melting point of 3D printed plastic, especially PLA. A number of designs were developed and tested that minimized the contact between the module and the 3D printed ring, provided protection from fingers touching the back of the hot modules, provided ample air flow,  yet minimized size and offered ease of installation.

Once the ring was finalized the basic clip could be created by subtracting a ring from a cylindrical blank in 3D space. However the notion of using tabs that would flex on the clip as the ring was inserted created a lot of difficulty when using brittle filaments like PLA–the tabs tended to break if the fit was too tight. A large number of tiny revisions of the slots for the tabs on the ring were required to achieve the best compromise of good fit with  minimal risk of breakage.

Thanks to my membership in multiple makerspaces I was able to test these designs in both ABS (good) and PLA (acceptable) on a wide variety of 3D printers. The primary work was done on a Stratasys uPrint SE using ABS but that was then tested on consumer-level printers from Makerbot, Makergear, Ultimaker, Deltamaker, and Printbot in PLA since most of us don’t own a $25,000 Stratasys. Ultimately small compromises were necessary throughout the 3D design to achieve acceptable fit on all parts of the lamp assembly across these printers.

I wanted to offer a variety of lamps that the ring with a LED module could clip into. I ultimately chose a desk or reading lamp, a decorative lamp shaped like a rocket, and a general utility lamp that would be the quickest and easiest to print. I am also making the ring and clip available on their own for people who would like to design the clip into their own shade.

The most problematic feature of developing the lamps was again finding the right compromise of fit among parts that would allow a firm fit without easy breakage, especially in the pivot points on the desk lamp and the utility light. Fancy adjustment plans involving sliding clips and ball sockets also had to be abandoned in favor of a simple hole-and-pin connectors .  PLA is just not friendly to parts that have to flex! I hope a less brittle filament eventually becomes the standard for low end printers.

The desk lamp presented additional problems in achieving adequate height with a sufficiently stable base while keeping print time low.

Once the 3D designs were finalized and printed for product pictures, it was on to kitting and putting it out there in the world….

I am developing a project for people with 3D printers who are looking for a functional design they can use around the house. The project is a LED lamp module that uses power from a USB cable. The module and a switched cable will be available on eBay at low cost with mounting screws and a lens. That will be accompanied by a series of free designs for different type of lamps posted to Thingiverse for people to download and print out to go along with the lamp module.

The process of designing an prototyping the lamp module will be the focus of this post.

In developing the lamp module there were at least 11 goals, which is a lot for a simple little light:

1. Small size–a smaller module would mean smaller and thus faster prints for the end user.
2. Low cost–I wanted to make this as accessible as possible, not to mention appealing for purchase.
3. Minimal part count–fewer parts keeps cost down.
4. Design for manufacturing–although I will be hand assembling these, I want to use manufacturable components such as surface mount electronics.
5. High light output–the brighter the light, the more useful it will be.
6. Neutral light color–since this may used as decorative light that shines through a 3D printed part it was important to keep it a neutral color (around 4000k color temperature).
7. Good light dispersion–a nice wide field for decorative use but an even narrow beam for reading or task lamp. An accessory lens provides this flexibility.
8. Appropriate power consumption–I did not want to exceed the 500mA limit for computer sourced usb, although I will not be encouraging people to power this from a computer.
9. Acceptable heat generation–a bright LED in a small package generates heat concentrated enough to melt a 3D print, which is obviously unacceptable.
10. Flexibility for different applications–I wanted to keep the type of lamp the module would be useful in as open as possible.
11. Ease of use–I wanted to come up with a lamp module that could be attached to a wide variety of 3D prints with minimal hassle.

It took a couple of months of tinkering with LED modules, heat sinks, resistor values, circuit board designs, usb jacks,  lenses, and even types of mounting screws to come up with a final design. The big bear was #9, heat generation. It took a combination of juggling all of the above plus the design of the 3D printed mounting ring to arrive at a lamp module that would not melt PLA.

The final design is certainly not perfect but functions well enough that I ordered 50 PCBs and 50 sets of components to make up a batch for testing and test marketing.

On to the lamp designs for 3D printing…………….

As a variation on the Desk Lamp 01 project I added a few features for a lamp I use at my electronics bench, namely a fan to draw away soldering fumes and a USB jack for 5 volt power. Details can be found on the Desk Lamp 02 project page.

This is a simple BB-8 cookie cutter I did in Tinkercad for a family cookie decorating party. It is just an outline so the decorating can get creative. The .stl file is available for printing from Thingiverse.

Here is another little toy for Orlando Makerfaire 2015. It’s more derivative that the things I usually make but still fun. The original is Theo Jansen’s Standbeest sculptures. The more immediate inspiration was a motorized toy one featured in Servo magazine awhile back.

This uses two continuous rotation servos to drive the legs, steered by two Sharp IR sensors and controlled by an Arduino pro mini.

Orlando Makerfaire is a lot of fun. But with approximately 2000 people a day passing by your table, you just can’t interact with everyone. So I wanted to bring a couple toys this year that could pretty much run by themselves. The first is this part machine, part tree, part eyeball thing (described in greater detail on the one-offs page).

The closer you get the more frantic it gets. If you get all the way up to it at present it just gets calm again, but I am planning to add a surprise or two for makerfaire.

As an experiment in extending 3D printing technology out to more traditional production techniques, I developed a composite stone stand for phones and small tablets. The project page includes all the details, including materials, resource files, process, and my failed experiments. I have also included a 30+ minute video of the casting and finishing process.

A limited number of these stands are available on Etsy. Or you can print yourself one in plastic using the 3D file on the project page.

As a first experience in creating a manufactured circuit board I decided to design a small prototyping board optimized for the type of project I typically undertake–one which uses an Arduino Nano along with a motor driver or other ICs and some components for sensors. I put together a page providing details of the board along with my first time experience in designing one and having it manufactured. The page also contains a link to the Fritzing project file for the board. I am putting 75 of these up for sale on Ebay. I will also bring some to Factur and the Orlando Makerfaire, so just ask me for one if you see me at one of those places.

In the meantime I have this neat box of boards sitting on my desk just asking to be put to work in projects……

I have started  a page of links to maker skill tutorials published by others here. It is a highly curated list of tutorials that I feel are accessible to beginners, relevant to the kind of maker projects provided on this site, and from reliable sources. Moreover, the focus will be on basic processes and components of commonly used hardware rather than projects, complex systems, software, or specific brands. At the moment, it contains a good list for electronics. I will be adding other subjects over time.

The primary purpose of the robot50 site is to share full materials lists and build instructions for introductory to intermediate level projects that people can build. However I have built a number of one-off projects, mostly interactive toys for maker fairs, that I thought I would post in summary form. They have their own page and are presented for inspiration and with some cautionary notes on things that didn’t work out the way I planned.