Oil Screen Hook

TL;DR: I designed and printed a custom hook to store our oil screen on the back of our cabinet door to save some space.  

Inspired by similar projects seen in various places online, I spent about an hour’s time measuring, designing, and printing a small custom hook to hang an oil screen on the back of a cabinet door.

Due to the simplicity of the part and the application, I decided to spend some time making deliberate choices to optimize performance. First was the design of the part itself. While I could have used a generic 3M command hook to achieve a similar effect, the tight custom fit of this hook prevents excessive movement and noise. Second, I decided to use PETG instead of PLA, a no-brainer for when strength is required. My last optimization was in the chosen print orientation. Despite requiring more support material, the orientation I used is actually ideal for the loading expected in this application. FDM printed parts are weakest parallel to the layer lines—that is, they are susceptible to delamination when loads pull the layers apart.

Quick project to save space in our pan cabinet.

That’s pretty much all I’ve got–here’s to a year full of fun projects in 2021!

Bailey Slow Feeder

TL;DR: I printed a slow feeder bowl for Bailey out of food safe filament and coated it with an FDA-compliant food safe resin. It works, but I think she hates it and me for making it.

I’ve wanted to experiment with 3D prints out of PETG for a while, and finally found some time to do so during this long Thanksgiving weekend. PETG (polyethylene terephthalate glycol-modified) is a 3D-printable plastic with numerous advantageous properties:

  • High strength
  • High density
  • High temperature
  • UV resistant
  • Food safe

The drawback is that it is a bit trickier than PLA (the most typical home 3D printed filament) to print. I invested an hour’s worth of time to adjust settings and complete two quick test prints before deciding I dialed my printer in enough to start a real project.

Our dog Bailey is a voraciously fast eater and I recently learned that various slow feeder bowls existed. However, most of the products on the market seem designed for larger dogs, and I wanted to make something that would fit in our existing holder. Spoiler image below:

Bailey’s custom slow feeder bowl fit perfectly!

The design of the bowl was straightforward. I measured the dimensions of our existing metal bowl, added another mm of thickness of the bowl for strength, added an extruded “B” in the middle to act as an obstacle, and finally made some cuts in the B to allow Bailey to access all the nooks and crannies. I took care to fillet any sharp edges away to ensure safety:

Left: Top view, Right: Iso view. I cut the “B” into an arch so Bailey could reach all the food and made sure to fillet all sharp edges.

The quality of my first real PETG print exceeded my expectations… Based on troubles I’ve read about people having, I expected some blobs/zits or stringing issues, but surprisingly, I didn’t have any real problems at all. The ease of support material separation was shocking too–99.8+% of my support came off in a single piece, and the remaining two pieces were easily removed with pliers:

Top: 3D print in various stages of completion. Bottom: Removal of support material. I was surprised at the great quality, high strength, and ease of support material for my first PETG print.

After the print was complete, I coated the bowl with this neat FDA 21 CFR 175.300 compliant resin I bought a while ago but hadn’t tried out before. The biggest pain point with the coating process was the 48-hour cure time.  Luckily this was a long weekend, haha.

Right: Top view of bowl post resin. Left-Top: Showing off shininess of the bowl. Left-Bottom: Water beading up on the print after washing. Not pictured: 48 hours of waiting, and the popsicle stick, old tofu container, and paintbrush all sacrificed to make this happen.

After washing the bowl with soap and water, I tested it out with Bailey by putting in a few training treats. She did not look very happy…

She eventually came around to eating, but clearly wasn’t happy:

I hope she doesn’t hate me forever because of this…

Does she look most annoyed, confused, angry, or disappointed?

Baymax Cord Lock

TL;DR: A cord lock for Tiff’s hat broke… so I made a replacement shaped like Baymax since I had white material installed in my printer and I was too lazy to change it, haha.

Tiff got a great sun hat from a friend’s beach birthday party last year. I use it almost every day when walking Bailey. I noticed that the cord lock was starting to break, so I decided to make something useful while scratching my maker itch now that the need for PPE has declined.

Since I currently have black TPU (an elastic material not really suited for this application) installed in one printer, white PLA installed in my other, and a severe lazy streak, I needed to design something white and ovoid.

White? Check. Ovoid? Check. Fun? Check Check Check.

With proper source material in place, knocking out the design was straightforward for me. I decided to use the sculpting tools in Fusion 360. Sculpting is great for quickly making organic shapes that don’t require a lot of exact dimensions. Fusion makes it super easy to combine sculpted forms with parametrically defined features as well. I split Baymax’s body into two parts, one main body and a removable front plate to install the spring and legs.

Sculpt and boolean tools in Fusion 360 made designing and cutting the parts up for 3d printing a breeze!

Since the part was very small, I initially had some troubles with Cura deciding some areas (primarily the cut out for feet to retract into the body for cord installation) were so thin that I must not have wanted material there. I solved this problem by reshaping the Baymax body a bit and scaling the parts up by roughly 15%.

Functional? Check.

Overall, I’m pretty happy with the results… despite it looking slightly terrifying, IMO… like Baymax lost a fight. Maybe I should have gone with some sort of squid ¯\_(ツ)_/¯.

As always, hope everybody is staying safe and healthy!

UPDATE: 7/25/2020:

Looking at the Baymax cord lock I made last week depressed me because it looks like his body is getting pierced by some sort of tentacled foe. I decided to replace it by designing a Blooper (the squid thing from Mario games), since it is also white, but looks natural with long arms:

I think Blooper looks better than Baymax cause the strings are tentacles XD

I used all the same tools I used for Baymax to make Blooper, but it was much faster the second time around. While I like this cord lock looks better, but Tiff doesn’t like it because of all the legs, hahaha ¯\_(ツ)_/¯.

Window Sill Shelf

TL;DR: It gets hot in SoCal so I overengineered a shelf to hold a fan to blow cool air into our bedroom at night.

Just a quick post this time—I decided to put my printer to work making another functional print! SoCal is a desert, so it gets very hot during the day, but cooler at night. A few days this past week were especially brutal. To help circulate the air at night, we use a little Vornado fan, but its effectiveness wanes when it doesn’t have access to cooler air.

A simple, but effective design. I originally intended to print the shelf itself too, but I found a piece of wood that I’ll cut later to eliminate the use of this piece of cardboard, haha.

I designed a very simple shelf comprised of brackets, a brace, and the shelf itself. I sized the brackets specifically for our bedroom windowsill. There is a very satisfying click during installation, but the shelf is very easily removable in case we need to close the window.

I didn’t end up printing the shelf part because I found a piece of spare wood which will work perfectly, and I installed a piece of cardboard until I find time to cut it. Although this specific design isn’t super generalizable, I decided to upload it to thingiverse anyway in case anybody is inspired to made minor modifications to fit their needs:


Stay safe and healthy!

#BlackLivesMatter Gear

TL;DR: I believe #BlackLivesMatter. I still can’t say anything more eloquently than what has been said by others elsewhere, so I’m going to chip into the cause in my own way. If you’ve donated to a reputable social justice charity, I’m more than happy to send you some 3D Printed #earsavers or touch-free door openers.

Despite law enforcement agencies across the country telegraphing they don’t believe so, black lives do matter. To help the cause in a small way, I designed a new earsaver and a touch-free door opener/keypad stylus.

The earsaver is a modified version of the NIH-approved design found here: https://3dprint.nih.gov/discover/3dpx-013615. No critical outside dimensions were altered, and the part remains very flexible. Earsavers are very useful for anybody who needs to wear a mask (aka EVERYBODY WHO LEAVES THEIR HOME). You put this on the back of your head and hook your mask straps around it instead of around your ears. This takes the pressure off your ears and makes wearing the mask much more tolerable.

I modified an NIH-approved design to allow wearers to show solidarity with the movement.

Creating the door opener/stylus was a bit more involved; I created the design from scratch, using a few existing designs as inspiration. The hook is useful for opening door handles without touching the surfaces. A strip of copper tape wrapped around the fist allows the stylus to function on capacitive touch screens, as long as you touch the bottom of the strip with your thumb. This is useful for pressing buttons at the self-checkout line in grocery stores.

This touch-free door opener doubles as a stylus useful for hitting capacitive-touch buttons at self-checkouts. The strip of copper tape is the secret-sauce which allows this functionality.

If you’d like some of these doodads, I’m happy to send them to you free of charge. Since I literally finalized the design at lunch today, I don’t have a huge stockpile right now. For now, I’m going to prioritize those who have donated to reputable social justice related charities, but I aim to eventually provide these for anybody who wants them, so feel free to reach out!

COVID: Endgame

TL;DR: Since the acute need for PPE has diminished, I am no longer producing parts on regular basis. However, I do have a reserve of face shields and earsavers remaining, and am more than happy to ramp up production if you or anybody you know need equipment.

Over the past 8 weeks, I personally manufactured about 1000 face shields and 1000 ear savers on my two 3D printers, delivering a quantity of about 880 of each to healthcare friends and friends of friends in places all over the country including: LA, SF, OC, Oakland, Tennessee, Oregon, South Carolina, Georgia, and New York. Furthermore, two local groups I work with have distributed over 75,000 and 22,000 face shields and other units of PPE, respectively.

However, it appears that more and more hospitals are getting their supply chains back in order, and the shortfalls do not seem as desperate as they were a few weeks ago.

This is what ~50 lbs of empty filament spools looks like

I feel this was a huge accomplishment, and I could not have done it without the support of everybody who chipped in for expenses—it was incredibly generous of you. I plan to donate the remaining funds to the charity Good360 in a few weeks if the need remains low and seems unlikely to ramp up in the short-to-medium term.

I hope everybody has a wonderful Memorial Day Weekend, and stays as happy and healthy as possible. I sincerely hope enough of us remain vigilant and change our habits enough to ensure the gains and sacrifices we’ve made the past few weeks are not wasted. I pray that the worst of this situation is truly over for us. However, if there’s one silver lining to this, I know that if the need for more PPE arises again, we’ll be able to ramp back up much faster next time.

Quick update — now with earsavers!

TL;DR: In addition to face shields, I’m now producing NIH-approved earsavers. Let me know if you need some!

About two weeks ago, I upgraded my old cloggy 0.4mm nozzle to a great 0.8mm nozzle courtesy of Micro Swiss (https://store.micro-swiss.com/). Making this switch greatly increased my printing capacity—when you go from a smaller nozzle to a larger one, the volume of material you can deposit increases by r^2–you reduce both the travel count within each layer, and increase the layer height at which you can print at. This leads to a huge boost in printing speed, with the drawback of losing details. However, for what I’m mass-producing right now, loss in detail is a very minor concern, so cutting my print time nearly in half on one printer is well worth the trade off.

While I continue manufacturing and delivering NIH-approved face shields on one printer, I’ve dedicated my other to the production of NIH-approved earsavers (https://3dprint.nih.gov/discover/3dpx-013759) for the next week or two. These popular devices are great for relieving pressure off the ears of healthcare workers who need to wear surgical masks for hours on end during their shifts. By the end of this week, I will have delivered over 350 of them (including shipments to South Carolina, Tennessee, Oregon, and NorCal!)

Here’s a snapshot of my life for the past few weeks:

Left: 75x frames and 260x earsavers ready to be delivered this weekend
Right-Top: I’ve chewed through quite a bit of material… each spool is 2 kg >.<
Right-Bottom: 100x frames and 400x shields delivered last week

Let me know if you or any of your healthcare worker friends need any face shields or earsavers! I’m happy to ship them out.

Again, hope everybody stays safe and healthy out there!

Ironman Figurine

TL;DR: I uploaded my first Thingiverse share! I improved the design of an existing Ironman model by adding pegs to allow for articulation and adhesive-less assembly.

I went on a work trip to Phoenix in early November. Fortuitously, my best friend growing up lives there and loves Ironman like I do. I decided to squeeze in a quick design and print project to gift him.

I found a decent looking Ironman figurine on Thingiverse here. This model is actually a remix of another project—the remixer made the part easier to print by separating the limbs. While this was a good step forward for printability, I further improved the design by adding pegs between the extremities and the main body:

The pegs I added are in red. They allow easy assembly plus articulation.

The boolean tools available in Fusion360 make it incredibly easy to complete simple changes like this. I undersized the peg in the CAD model, but small variations in print settings and nozzle wear and tear make perfect fits a bit tricky. In fact, it took me a few tries to get the pegs working really well, but the prints were short, and the results were worth it:

Assembly in process

Given that this project originated directly on thingiverse, I thought it was only right to give back to the community and share my very first remix here: https://www.thingiverse.com/thing:3998580. The number of views and downloads of this model pleasantly surprised me, given the simple and obvious nature of the change I made. I’ll probably consider sharing more stuff going forward… we’ll see ¯\_(ツ)_/¯.

I think the assembly with articulation turned out pretty well—the yellow looks vaguely gold-ish, so the only thing missing is some red paint:

He just needs a paint job

EL Headbands done!

TL;DR: I finished the EL headbands I’ve been working on :D.

I finished up the electroluminescent headbands I described in my post a few weeks ago here. Since my prototype was close to the final product, completing the production was fast after I received the custom fabric components.

As in the prototype, EL wire was passed through the printed channels and connected to a DC to AC inverter for power. I found nifty coin battery sized inverters, which fit directly on the bands without too much interference. The most time consuming portion of the build was attachment of the plastic to the fabric, since I’m bad at hand sewing.

Here’s the build gallery:

Here’s a bonus gif, with a little preview of a flag project I’ve been working on as well…

Thanks Sara and Vi for demo’ing 😀

Faux-Neon Signage

TL;DR: For my friend Gina’s birthday, I made her a faux-neon sign to decorate her new condo with. I ended up making a few different versions of this sign and through the process, I learned several useful tricks to speed up vector image modifications, which will definitely make it easier for me going forward. 

I continued playing with el wire since I bought so much for my headband project. Since my friend’s birthday was coming up, I figured it was a great opportunity to make something cool with it. I decided to make a faux-neon sign reading “Mama G’s House”.

I started by searching for neon sign fonts on google and downloaded a few to try out including “Warnes”, “La Patio Script”, “I am online with u”, and “Fenotype Neon”. All of them were free to download, but not all of them were free for commercial usage, which is fine for this project as I’m not selling it.

The first prototype I made used Warnes as the base font. I really liked how the letters all connect at the bottom. However, I needed to do a bit of surgery in Inkscape to connect the disparate words after vectorization:

The main modifications I made to this first font were just around connecting the letters and adjusting some of the spacing

I imported the SVG directly into a sketch Fusion 360 and resized it to ensure I had a ~3mm wide channel all over. Next, I modified the sketch to remove areas near the bottom where the lettering overlapped. In a fashion similar to what I did for the EL headbands, I extruded a positive model of the letters. Next, I needed to move the apostrophe body and combine it with the rest of the lettering. Then, I created a sketch, offset the entire object, and cleaned up the line overlapping lines created by the offset tool. After extruding the outlined body, I cut the positive lettering model out:

I reused the technique I discovered while making the EL headbands of cutting the positive channel from the main body

After slicing the STL in Cura, and waiting about 3 hours for production, the print came out pretty well:

However, with the physical model in front of me, I saw the font I used had a few issues. Primarily, although the channels I made fit the el wire, there were too many places where stringing it required a double back, which was not accounted for. Oops. Luckily, I hadn’t spent a lot of time on this, and I figured Gina could still use it as a nice decoration even without lighting effects.

The next font I tried was called “I am online with u” which had the advantage of being a single connected line. Although this font was more ideal out of the box, I still needed to tweak the vector version to make it work properly. Essentially, I just modified the “corners” of the letters to allow for more space wherever they changed direction, I adjusted the spacing between words and letters, and I moved and combined the apostrophe to overlap with the letters.

I modified this font a bit more heavily to ensure a good print. The biggest tweak was widening the letters where they changed direction so the EL wire could bend around.

My workflow in Fusion 360 was essentially identical to the one I used for the previous version of the sign: import svg, scale, and clean up sketch -> extrude a positive channel -> offset the body and extrude the outline -> use the combine tool to cut the positive channel away from the outlined body. Unfortunately, this part was a bit too big to fit on my printer in one piece, so I needed to split it into two. The split created a physical weakness which I shored up by creating a small base to hold it together and help the entire assembly stand upright.

The split was unfortunate but necessary to allow me to actually manufacture the sign. The base I made fit very well and helps keep the assembly standing too.

The print didn’t take very long—maybe about 4 hours in total for all the pieces. I was pretty happy with the results, and I think she was too 🙂