Cheap And Effective Mosquito Trap Looks Like A Disco

August 3, 2020 by Adil Malik 34 Comments

Words cannot quite articulate the collective loathing humankind has for mosquitoes, and rightfully so! These parasite peddling, blood sucking little critters are responsible for a great deal of human suffering. Mosquito-borne diseases such as malaria still account for a significant proportion of human mortality, especially in under-developed parts of the world . So it’s no wonder that people try to reduce their numbers; see this latest $40 mosquito trap by [jacobsk]. (Video, embedded below.)

The idea is critically simple, opening up the potential for widespread deployment. The base and body of the trap are made out of three five-gallon buckets with a mini desk fan sandwiched in between, providing suction into the main trap bin. An opening is cut in the top bucket as a point of entry, and an old school incandescent blacklight is mounted in the centre, with just enough IR and UV output to entice these little vermin, who will definitely regret mistaking it for a black-light rave.

[jacobsk] also does a very good job of showing every step of its construction in his videos. Whilst this solution is purposefully low tech, check out this admittedly overcooked way of killing mosquitoes, with a laser turret.

Continue reading “Cheap And Effective Mosquito Trap Looks Like A Disco” →

Digi-Key Hacks UV Into Conveyor Line To Protect Warehouse Staff

July 4, 2020 by Orlando Hoilett 21 Comments

No doubt that every hacker has already heard of Digi-Key, the electronic component distributor that makes it just as possible to order one of something as it is to order a thousand of it. As an essential business, Digi-Key has been open during the duration of the lockdown since they support critical manufacturing services for virtually every industry on the planet including the medical industry.

Ensuring their workforce stays healthy is key to remaining open and as part of their efforts they hacked together a nice addition to their sanitation regime. They use around 8,000 plastic totes to transport components around the distribution center and devised a way to sanitize tote coming in from the receiving area using a UV light tunnel. From their sanitation plan we can see this is in addition to the fogging system (likely a vaporized hydrogen peroxide system) used to regularly sanitize the totes passing throughout the warehouse.

They developed a UV light tunnel that wraps around the conveyor rollers. The design includes a sensor and a timer to control when and how long the UV lights are on. The totes are a frequent touch point for employees, and running incoming shipments through the UV light tunnel helps decrease the chance of exposure.

Thinking of using UV as a sanitation tool? Make sure you do your research on the wavelengths you need and vet the source of critical components. [Voja] ran into UV lamps that were anything but germicidal.

3D Printering: Sticky Resin Prints And How To Fix Them

June 4, 2020 by Donald Papp 39 Comments

After going through all the trouble of printing a part in resin, discovering it feels sticky or tacky to the touch is pretty unwelcome. Giving the model some extra ultraviolet (UV) curing seems like it should fix the problem, but it probably does not. So, what can be done?

The best thing to do with a sticky print is to immediately re-wash it in clean isopropyl alcohol (IPA) before the UV present in ambient light cures stray resin. If the part remains sticky after it is dry, more aggressive steps can be taken.

We’ll get into those more extreme procedures shortly, but first let’s understand a bit more about how resin works, then look at how that applies to preventing and removing tacky surfaces on finished prints. Continue reading “3D Printering: Sticky Resin Prints And How To Fix Them” →

Can You Print With Highlighter Ink?

March 29, 2020 by Lewin Day 30 Comments

With huge swathes of people either out of work or working from home, many are now attempting all manner of exciting or silly projects in their downtime. [Emily Velasco] is no exception. She decided to explore the feasability of printing with highlighter ink.

The hack starts with a rather ancient inkjet printer, so old that it works with tractor feed paper. [Emily] set about gutting several highlighter pens and squeezed out the ink reservoirs into a ladle. The printer’s ink cartridge was then filled with the fluid, and a test print was fired off. Upon initial extraction, it appears blank. However, with the aid of a UV light, the printed pattern is revealed. It appears that the inkjet is printing a very faint image, such that the system almost works as an “invisible ink”.

It’s a fun little hack with an old printer, made easier as it lacks the DRM of newer models. It’d probably be quite achievable with a dot-matrix, too. If you’re similarly tinkering in the innards of your peripherals, be sure to let us know. Video after the break.

Continue reading “Can You Print With Highlighter Ink?” →

“Glixie” Puts A New Spin On Glow-In-The-Dark Displays

March 20, 2020 by Dan Maloney 4 Comments

For as many projects as we see using Nixie tubes in new and unusual ways, there’s a smaller but often very interesting cohort of displays that fit into the “Nixie-like” category. These are projects where something other than the discharge of noble gasses is being used to form characters. This scrolling phosphorescent single-character display is one such project, and we think it looks fabulous.

Following the *ixie naming convention characteristic of these builds, [StephenDeVos] dubbed this the “Glixie.” This is on par with the size of a [Dalibor Farny] handmade Nixie, but not so big to be unwieldy. The display modality is glow-in-the-dark film that rotates past a vertical string of UV LEDs, which light up in turn as the cylinder rotates, building up the dot-matrix character column by column. There’s some fading of the first column by the time the whole character is built up, but not enough to be objectionable. We like the whole build, with laser-cut wood and the brass and steel hardware. Check it out in the video below.

If this phosphorescent display strategy seems familiar, it’s because we’ve seen it before. Remember this persistence of phosphorescence display? Or perhaps this time-writing robot clock? It’s not a new idea, but [Stephen]’s execution can’t be beat.

Continue reading ““Glixie” Puts A New Spin On Glow-In-The-Dark Displays” →

Improving Exposure On A Masked SLA Printer

November 12, 2019 by Tom Nardi 6 Comments

It’s taken longer than some might have thought, but we’re finally at the point where you can pick up an SLA 3D printer for a few hundred bucks. These machines, which use light to cure a resin, are capable of far higher resolution than their more common FDM counterparts, though they do bring along their own unique issues and annoyances. Especially on the lower end of the price spectrum.

[FlorianH] recently picked up the $380 SparkMaker FHD, and while he’s happy with the printer overall, he’s identified a rather annoying design flaw. It seems that the upgraded UV backlight in the FHD version of the SparkMaker produces somewhat irregular light, which in turn manifests itself as artifacts on the final print. Due to hot spots on the panel, large objects printed on the SparkMaker show fairly obvious scarring.

Now you might expect the fix for this problem to be in the hardware, but he’s taken it in a different direction. These printers use an LCD panel to block off areas of the UV backlight, thereby controlling how much of the resin is exposed. This is technique is officially known as “masked SLA”, and is the technology used in most of these new entry level resin printers.

As luck would have it, the SparkMaker FHD allows showing various levels of grayscale on the LCD rather than a simple binary value for each pixel. At least in theory, this allows [FlorianH] to compensate for the irregular backlight by adjusting how much the UV is attenuated by the LCD panel. He’s focusing on the printer he personally owns, but the idea should work on any masked SLA printer that accepts grayscale values.

The first step was to map the backlight, which [FlorianH] did by soaking thin pieces of paper in a UV reactant chemical, and draping them over the backlight. He then photographed the illumination pattern, and came up with some OpenCV code that takes this images and uses the light intensity data to compensate for the local UV brightness underneath the sliced model.

So far, this method has allowed [FlorianH] to noticeably reduce the scarring, but he thinks it’s still possible to do better. He’s released the code for this backlight compensation script, and welcomes anyone who might wish to take a look at see how it could be improved.

An uneven backlight is just one of the potential new headaches these low-cost “masked” SLA printers give you. While they’re certainly very compelling, you should understand what you’re getting into before you pull the trigger on one.

When Does Moving To Resin 3D Printing Make Sense?

October 2, 2019 by Donald Papp 50 Comments

An Elegoo Mars resin 3D printer, straight to my doorstep for a few hundred bucks. What a time to be alive.

Resin-based 3D printers using digital light processing (DLP) and especially stereolithography (SLA) are getting more common and much more affordable. Prosumer-level options like Formlabs and the Prusa SL1 exist, but more economical printers like the Elegoo Mars, Anycubic Photon, and more can be had for a few hundred bucks. Many printers and resin types can even be ordered directly from Amazon, right at this moment.

Resin prints can look fantastic, so when does it make sense to move to one of these cheap resin printers? To know that, consider the following things:

The printing process and output of resin printers is not the same as for filament-based printers. Design considerations, pre-processing, and post-processing are very different.
Resin printing has a different workflow, with consumables and hidden costs beyond the price of resin refills.

Things may not be quite where fused deposition modeling (FDM) printers were just a few short years ago when we were extremely impressed with the quality of printer one could get for about $200, but it is undoubtedly far more accessible than ever before. Let’s look at how to inform a decision about whether to take the plunge. Continue reading “When Does Moving To Resin 3D Printing Make Sense?” →