Sewing Machine at CRASHspace Wearables Wednesdays

I brought a “naked” sewing machine to the February 2020 edition of Wearables Wednesdays. Wearables Wednesdays is a regularly occurring monthly meetup at CRASHspace LA, a makerspace in Culver City whose membership includes a lot of people I love to chat and hack with. But Culver City is a nontrivial drive from my usual range. So as much as I would love to frequently drop by and hang out, in reality I only visit at most once a month.

The sewing machine belongs to Emily who received it as a gift from its previous owner. That owner retired the machine due to malfunction and didn’t care to have it repaired. At our most recent Disassembly Academy, one of the teams worked through the puzzle of nondestructively removing its outer plastic enclosure. There were several very deviously hidden fasteners holding large plastic pieces in place.

Puzzling through all the interlocked mechanisms consumed most of the evening. Towards the end, Emily soldered a power cable (liberated from another appliance present at the event) to run its motor, which was the state I brought in to Wearables Wednesdays.

This event was focused on wearables, so everyone has some level of experience with a sewing machine. And it is also an audience who have experience and interest in mechanical design, so it was a perfect crowd for poking around a sewing machine’s guts.

When the outer enclosure was removed, a broken-off partial gear fell out. The rest of the gear was found to be part of the mechanism for selecting a sewing pattern. At the end of Disassembly Academy, our hypothesis for machine retirement was because of its inability to change patterns due to this broken gear.

Further exploration at CRASHspace has updated the hypothesis: there is indeed a problem in pattern selection, but probably not because of this broken gear. We can see the large mechanical cam mechanism that serves as read-only memory for patterns, and we can see the follower mechanism that can read one of several patterns encoded on that cam. However, pushing on the internal parts of the mechanism, we couldn’t get the follower to move to a different track.

New hypothesis: There is a problem in the pattern mechanism but it’s not the gear. The pattern selection knob was turned forcefully to try to push past the problem, but that force broke the little gear. It was a victim and not the root cause.

Exploratory adventures of this sewing machine will continue at some future point. In the meantime, we have a comparison reference from a friend who owns a sewing machine that predated fancy pattern features.

MatterHackers 3D Printing And Space Event

Even though Santa Monica is technically in the same greater LA metropolitan area as my usual cruising range, the infamous LA traffic requires a pretty significant effort for me to attend events in that area. One such event worth the effort was the “3D Printing and Space” event hosted by MatterHackers, Ultimaker, and Spaceport LA.

Like the previous MatterHackers event I attended, there is a nominal main event that is only part of the picture. Just as interesting and valuable is the time to mingle and chat with people and learn about their novel applications of 3D printing. Sometimes there is a show-and-tell area for people to bring in their projects, but it wasn’t clear from event publicity materials if there would be one at this event. I decided to traveled to Santa Monica via public transit, which meant Sawppy couldn’t come with me, which was just as well since the exhibit area was minimal and mostly occupied by items brought by members of the speaking panel.

I started off on the wrong foot by mistaking Matthew Napoli of Made in Space for someone else. Thankfully he was gracious and I learned his company built and operates the 3D printer on board the international space station. It was tremendously novel news a few years ago, and the company has continued to evolve technology and widen applications. Just for novelty’s sake I tried printing that wrench on my Monoprice Mini some time ago, with very poor results. Fortunately the Made in Space printer on board ISS is a significantly more precise printer, and Matthew Napolo brought a ground-printed counterpart for us to play with. It was, indeed, far superior to what I had printed at home. A question he had to answer several times throughout the night is whether FDM 3D printing in space still require support materials, which we use to hold melted filament up against gravity. The answer is that (1) their testing found that even though there’s no gravity, extruded filament nozzle has momentum that needs to be accounted for, and (2) Made in Space design their “production” parts to not require support material when printed either on earth or in space.

On an adjacent table were several 3D printed mounting brackets brought by Christine Gebara. Each of them had identical mounting points, but they had drastically different structural members connecting them. Their shape appeared to have been dictated by numerical evolution algorithms becoming available under several names. Autodesk calls theirs “generative design“. Learning how to best take advantage of such structures is something Christine Gebara confirmed was under active development at JPL.

Kevin Zagorski of Virgin Orbit brought something I didn’t recognize beyond the fact it had bolt patterns and fittings to connect to other things. During the discussion he explained it was part of a test rocket engine. While the auxiliary connecting pieces are either commodity parts or conventionally machined, the center somewhat tubular structure was 3D printed by a metal sintering(?) printer. 3D printing allowed them to fabricate a precise interior profile for the structure, and the carbon deposits inside a testament to the fact this piece was test-fired. He also described a development I was previously unaware of: they are using machines that has both additive and subtractive tooling. This meant they can build parts of a metal structure, move in with cutters or grinders to obtain a desired surface finish on the interior of that structure, before proceeding to build remaining parts. This allows them to get the best of both worlds: geometries that would be difficult to make by machining alone, but with interior surface finishes that would be difficult to make with 3D printing alone. Sadly he believes these machines satisfy a very narrow and demanding niche, so this capability is unlikely to propagate to consumer machines.

I didn’t know about Spaceport L.A. until this event, but I had been dimly aware of a cluster of “New Space” companies in the area. Southern California has been a hotbed of aerospace engineering for as long as that has been a field of engineering, though there have been some painful periods of transition such as severe industry downsizing at the end of the Cold War following collapse of the Soviet Union. But with SpaceX serving as the poster child for a new generation of space companies, a new community is forming and Spaceport L.A. wants to be the community hub for everyone in the area.

But even though some portray “Old Space” companies as dinosaurs doomed to extinction, in reality they are full of smart engineers who have no intention of being left behind. Representative of that was Andrew Kwas from Northrup Grumman and the entourage he brought with him. He said several times that the young Northrup Grumman engineers in his group will take the company into the future. It was fun to speak with a few of them as they had set up shop at one of the tables presenting pieces from their 3D printing test and research. One of them (I wish I remembered her name) gave me my first insight into support materials for laser sintering metal 3D printing. I thought that, since these parts were formed out of a bed of metal powder, it would not need support materials. It turns out I was wrong, and support materials are still required for mechanical hold and also for thermal dissipation. I don’t know if I’ll ever have the chance to design for laser sintering printing, but that was a valuable first lesson.

And last but not least, I got to talk to Kitty Yeung about her projects that express love of space through 3D printing. It’s a little different from the other speakers present as she’s not dealing with space flight hardware, but they are an important part of the greater community for space enthusiasm. In between esoteric space hardware, it’s great to see projects that are immediately relatable to hobbyists present.

I look forward to the next MatterHackers public event.

Sparklecon 2020 Day 2: Arduino VGAX

Unlike the first day of Sparklecon 2020, I had no obligations on the second day so I was a lot more relaxed and took advantage of the opportunity to chat and socialize with others. I brought Sawppy back for day two and the cute little rover made more friends. I hope that even if they don’t decide to build their own rover, Sawppy’s new friends might pass along information to someone who would.

I also brought some stuff to tinker at the facilities made available by NUCC. Give me a table, a power strip, and WiFi and I can get a lot of work done. And having projects in progress is always a great icebreaker for fellow hardware hackers to come up and ask what I’m doing.

Last night I was surprised to learn that one of the lighting panels at NUCC is actually the backlight of an old computer LCD monitor. The LCD is gone, leaving the brilliant white background illuminating part of the room. That motivated me to dust off the giant 30-inch monitor I had with a bizarre failure mode making it useless as a computer monitor. I wasn’t quite willing to modify it destructively just yet, but I did want to explore the idea of using the monitor as a lighting panel. Preserving the LCD layer, I can illuminate things selectively without overly worrying about the pixel accuracy problems that made it useless as a monitor.

The next decision was the hardest: what hardware platform to use? I brought two flavors of Arduino Nano, two flavors of Teensy, and a Raspberry Pi. There were solutions for ESP32 as well, but I didn’t bring my dev board. I decided to start at the bottom of the ladder and started searching for Arduino libraries that generate VGA signals.

I found VGAX, which can pump out a very low resolution VGA signal of 160 x 80 pixels. The color capability is also constrained, limited to a few solid colors that reminded me of old PC CGA graphics. Perhaps they share similar root causes!

To connect my Arduino Nano to my monitor, I needed to sacrifice a VGA cable and cut it in half to expose its wires. Fortunately NUCC had a literal bucketful of them and I put one to use on this project. An electrical testing meter helped me find the right wires to use, and we were in business.

Arduino VGAX breadboard

The results were impressive in that a humble 8-bit microcontroller could produce color VGA signals. But they were not very useful in the fact that this particular library is not capable of generating full screen video, only part of the screen was filled. I thought I might have done something wrong, but the FAQ covered “How do I center the picture” so this was completely expected.

I would prefer to use the whole screen in my project, so my search for signal generation must continue elsewhere. But seeing VGAX up and running started gears turning in Emily’s brain. She had a few project ideas that might involved VGA. Today’s work gave a few more data points on technical feasibility, so some of those ideas might get dusted off in the near future. Stay tuned. In the meantime, I’ll continue my VGA exploration with a Teensy microcontroller.

Sparklecon 2020: Sawppy’s First Day

I brought Sawppy to Sparklecon VII because I’m telling the story of Sawppy’s life so far. It’s also an environment where a lot of people would appreciate the little miniature Mars rover running amongst them.

Sparklecon 2020 2 Sawppy near battlebot arena

Part of it was because a battlebot competition was held at Sparklecon, with many teams participating. I’m not entirely sure what the age range of participants were, because some of the youngest may just be siblings dragged along for the ride and the adults may be supervising parents. While Sawppy is not built for combat, some of the participants still have enough of a general interest of robotics to took a closer look at Sawppy.

Sparklecon 2020 3 Barb video hosting survey

First talk I attended was Barb relaying her story of investigating video hosting. Beginning of 2020 ushered in some very disruptive changes in YouTube policies of how they treat “For Kids” video. But as Barb explains, this is less about swear words in videos and more about Google tracking. Many YouTube content authors including Barb were unhappy with the changes, so Barb started looking elsewhere.

Sparklecon 2020 4 Sawppy talk

The next talk I was present for was my own, as I presented Sawppy’s story. Much of the new material in this edition were the addition of pictures and stories of rovers built by other people around the country and around the world. Plus we recorded a cool climbing capability demonstration:

Sparklecon 2020 5 Emily annoying things

Emily gave a version of the talk she gave at Supercon. Even though some of us were at Supercon, not all of us were able to make it to her talk. And she brought different visual aids this time around, so even people who were at the Supercon talk had new things to play with.

Sparklecon 2020 6 8 inch floppy drive

After we gave our talks, the weight was off our shoulders and we started exploring the rest of the con. During some conversation, Dual-D of NUCC dug up an old school eight inch floppy drive. Here I am failing to insert a 3.5″ floppy disk in that gargantuan device.

Sparklecon 2020 7 sand table above

Last year after Supercon I saw photographs of a sand table and was sad that I missed it. This year I made sure to scour all locations to make sure I can find it if it was present. I found it in the display area of the Plasmatorium drawing “SPARKLE CON” in the sand.

Sparklecon 2020 8 sand table below

Here’s the mechanism below – two stepper motors with belts control the works.

Sparklecon 2020 9 tesla coil winding on lathe

There are full sized manual (not CNC) lathe and mill at 23b shop, but I didn’t get to see them run last year. This year we got to see a Tesla coil winding get built on the lathe.

For last year’s Sparklecon Day 2 writeup, I took a picture of a rather disturbing Barbie doll head transplanted on top of a baseball trophy. And I hereby present this year’s disturbing transplant.

Sparklecon 2020 WTF

Sawppy has no idea what to do about this… thing.

Watching Operation Of Electron Microscope Live Was Surprisingly Interesting

It’s always amazing to see what people bring to the Hackaday Superconference. I think the audience would appreciate my project Sawppy, but I didn’t bring my rover to Supercon for two reasons. First, Sawppy is somewhat unwieldy and bulky and second, I expect to be pretty busy as part of event staff helping out on badge logistics.

The second reason held true throughout the weekend, but I was put to shame on the first front because Adam McCombs (Twitter @nanographs) brought a scanning electron microscope. I never thought they were very portable and I was right, but that didn’t stop Adam! It occupied what little open space there was in the DesignLab shop area. I’ve seen SEM imagery and thought it might be fun to take a closer look, but what I didn’t realize was how cool it was to watch one in operation.

I never got time at the operator console, but I watched others turn knobs at their disposal. I had not known how many different parameters were adjustable to highlight different features on the sample. When we see a published picture generated from a SEM, an operator has already adjusted these knobs to the appropriate settings. Seeing less-than practiced operators adjust them live and experiment to see what works was mesmerizing.

I was also surprised at how feedback is visible immediately. It was explained to me the whole machine is a very analog process. The path from the electron beams striking the sample to picture on operator console CRT has no digital frame buffers or processing inserting delay. Every once in a while an image is recorded to the adjacent laptop, and that process consumes several seconds, but the knob-twiddling is effectively instantaneous on CRT as are interactions with the sample. I saw some small specs of dust dance around and initially thought it was due to air movement, but then I learned the sample is held in a vacuum. What is moving the dust? The electron beam!

My mind evaluates this technology from the perspective of an optical camera, and from that perspective the available range of magnification is astounding. Traversing several orders of magnitude of magnification with a single twist of a knob. I saw no indication that a SEM has any equivalent of focus or depth of field limitations: everything in the image is always razor sharp. I was not surprised to see panning across the sample, but I was surprised to see tilt was an option as well to see some items from different perspectives.

Watching a SEM in operation was not something I knew I needed to see until I saw it. The pictures afterwards are a great reminder, but no match for the live experience. The opportunity doesn’t come often, but if one is available I highly recommend it.


Sawppy at DTLA Maker Faire 2019

Sawppy returned to the downtown Los Angeles Mini Maker Faire for 2019 as a roaming exhibit. This is a change from last year where Sawppy was part of a rover themed booth with other JPL Open Source Rovers. Sadly this year we were missing representation from the JPL Open Source Rover project, none of the three rovers from last year were present this year.

Los Angeles Maker Faire has grown even more this year and spilled into the street, specifically 5th Street adjacent to the library which was shut down for the event to make room for an additional row of exhibits. Many of the larger booths were out here, including a robot combat arena and a few car projects like the Eggscape Eggsperience.

There was forecast for rain, which dampened things literally and otherwise. Fortunately Sawppy is prepared for rain with a rain coat developed for Maker Faire San Mateo earlier in the year, so the light rain was not a problem.

I have fun showing Sawppy to interested attendees, but it is also an opportunity to chat with other like-minded exhibitors. I started trying to strike up conversation with people as soon as I got in line to check in as a maker. It turns out I was behind a member of the Air Quality Management District’s Air Quality Sensor Performance Evaluation Center. They were here at Maker Faire to tell people about the availability of low-cost air quality sensors. Both for AQMD’s own purposes and as something that could be fun for makers to tinker with. They brought a few sensors for show and I asked if Sawppy could act as a mobile air quality sensor for a day… and they said yes!

Even though no JPL OSR builds were present, Sawppy was not the only rover there but most of the others were static 3D-printed models. Probably from here. The one I found actually interesting is a motorized version that was done as an example application of the 3DoT board by Humans for Robots.

It was a fun day of adventure for Sawppy, topped off with a shout-out from Make!

Freebie Supercon SAO from

Digging through some old piles, found this advertisement freebie given out at Supercon 2018. (This was handed out by one of the attendees and not part of the conference goody bag.) The board already has all the surface mount pieces, I just need to solder the two through-hole components: the LED and the SAO header. It should be a short soldering project, might as well give it a shot.


With writing on both sides, I realized it wasn’t obvious which side each component should be soldered to. Well, I wasn’t going to use it as a badge SAO anyway, so it didn’t really matter. I chose arbitrary directions. Supercon 2018 SAO 40 connector

I’m not familiar with this “Qwiic” connector. It looks like something these guys are trying to promote as an interconnect for an ecosystem of components. I guess they saw Seeed Studio’s Grove Connectors and decided they had a better idea? This little giveaway didn’t exactly entice me to dive in to their system, but it did let me know it existed and to look it over. I guess mission accomplished for this little freebie giveaway.


I used my bench power supply to deliver 3.3 volts to the input pins. The LED lit up and that’s when I learned it was a fast color-changing LED. The lens is frosted instead of clear like the ones I’ve been using for fun, but the same basic idea.

It lights, it’s fine.

Sawppy Attends MatterHackers Modern Creators Night

MatterHackers is a local supplier for 3D printing. They also carry other products catering to the same hobbyist-grade audience for small scale fabrication, such as laser cutters and CNC engravers. I’ve bought much of my supplies — including the PETG filament used to print the current iteration of Sawppy — from MatterHackers.

I’ve met some of the people of MatterHackers at Yuri’s Night, and been extended an invitation to visit their headquarters where there’s a showroom area. But I have yet to take them up on that invitations because, while MatterHackers is within driving distance, it is a nontrivial drive accounting for LA traffic. Going to that area is basically a day trip, and it kept not happening.

But when Sawppy was invited to be at their Modern Creators Night event, that was enough motivation for me to pack up and take that trip. At the event, I learned it is a scaled-up version of an occasional meetup MatterHackers used to hold at their main office, but there was no longer enough space there. Their business has grown, as has the size of the crowds. Hence – a new event at a venue with a new format.

Sawppy arrived and started roaming the exhibit area as rovers tend to do. But when it came time for the speakers to present, Sawppy was presented with a table for static exhibit. I made some signage I could tape to the table, to explain Sawppy when I’m not present to tell the story.

Sawppy on small MatterHackers display table

There were a lot of 3D prints on exhibit by other makers, and one of them decided to loan their little printed model of Curiosity to keep Sawppy company during speaker presentations. I was happily surprised when I saw this little guy, and didn’t meet its owner until later. I regret to say I’ve already forgotten her name, but her generous and appropriate loan is very much appreciated!

Sawppys little friend

A Day At CRASH Space LA

Visiting CRASH Space LA has been on my to-do list ever since I was introduced to Barb and Jay at Maker Faire 2018. We’ve seen each other at numerous events since then and it was pretty ridiculous that I see them more often in San Mateo than our home town. The problem is that they are on the far side of the basin. Going to Culver City in the context of infamous LA traffic meant a visit is not “I’ll just stop by.” It is a day trip kind of expedition! Finally Emily and I visited during their “Mega Take Apart & Swap Meet” day this month.

I brought some things but Emily brought more, and they were more interesting. She tore into some sort of retired dental surgery tool with components indicating high voltage operation. We’re not sure why a dentist would need high voltage in our mouths, and we didn’t much care. (Or chose not to think about it.) What’s inside is far more interesting.

I dug into another box Emily had brought. Some sort of power supply that had all appearance of being an one-off homebuilt project.

After the take-apart event Emily went off to visit friends living in that part of town. I stuck around CRASH Space for their Video Dim Sum event where I learned there are a lot of very odd things available on YouTube. I expected this, so it was a 100% success on that front. However my taste rarely aligned with the people who submitted videos so my overall entertainment-to-time ratio was pretty poor. I did learn some interesting things that I would not have otherwise, so it was still a fun thing to try at least once.

Out of all the videos that were shown, just one of them were memorable and compelling enough for me to go find and rewatch. Here it is, my personal winner of Video Dim Sum:

Padadena Chalk Festival 2019

This past weekend was spent looking over artists working intently at Paseo Colorado for Pasadena Chalk Festival 2019. I feel it is to chalk artists what badge hacking at Supercon are for electronics people. Since I never graduated beyond the kindergarten stage of chalk art, I learned about surprising variety of tools and techniques for applying chalk to concrete. As someone who loves to learn about behind-the-scenes of every creation, it’s fun to revisit certain favorite pieces to see them progress through the weekend.

There were many original works, but most of my attention were focused on recreations of animated characters and scenes I’ve already seen. A notable departure from this pattern was a large mural depicting space exploration including my favorite Mars rover Curiosity:

Monsters, Inc. characters by Jazlyn Jacobo:

Kiki’s Delivery Service:

Aladdin’s Genie and Carpet play a game of chess. Drawn by Jen:

A scene from Toy Story 4 teaser, drawn in front of the theater which will be playing the movie next weekend. Drawn by Gus Moran:

Lion Kings Simba and Mufasa by Kathleen Sanders. This was quite fitting since it was also Father’s day:

Grandfather and grandson from Coco feature in this highly detailed composition by Patty Gonzalez:

Other works I liked:

This artist, who is drawing a chalk portrait of Luke Skywalker as X-Wing pilot, brought along a 3D prop in the form of a full-sized R2-D2.

Chalk festival R2D2

The most novel piece was by C.Nick in the Animation Alley. Here I expected to find artists working with animated characters… I was delighted to find an actual animated chalk drawing.

Chalk festival C Nick tinkerbell



Flagship Maker Faires May Be Over But Making Will Not Stop

When call for makers opened up for Maker Faire Bay Area 2019, I had not planned to apply because any trip to the San Francisco Bay Area is an expensive proposition. But with encouragement from friends, I applied Sawppy and was accepted. I had a great time at the original and still flagship Maker Faire! The fantastic experience in San Mateo certainly made the dent in my personal finances easier to bear. But today we received sad news, something we heard whispers about before the event turned out to be true: Maker Media, the company behind Maker Faire, is in a state of insolvency.

While the company still technically exists and restructuring, the general trends that led to this point are undeniable: dropping attendance and sponsorship meant revenue is down, while expenses of operating in the Bay Area have continued to grow. There’s no corporate restructuring that will change any of those inconvenient trends. Maker Faire Bay Area 2020 (and beyond) are unlikely to happen.

People are understandably sad, and I share the feeling. But there are also people who declare this the end of the maker movement and I vehemently disagree. What we’ll lose is a commercial entity that sought to make a business out of organizing and channeling maker energy. It is an important and useful part, but not nearly the whole, of the maker community. Sure, it was great to have a concentrated focus of this energy in San Mateo for a single weekend, but that energy still exists and will find other channels of expression. Maker Media had already successfully franchised the concept out to many non-Flagship Maker Faires around the world, something they hoped could continue. But even if that could no longer be organized under a centralized Make banner, makers will continue to gather under various different names.

Creative resourceful problem-solving ingenuity is the mark of a true maker. The loss of a corporate entity will not change that. We lost a fantastic place to congregate but that is all. We are not going anywhere.

First CTF At LayerOne 2019

The term “Capture the Flag” can mean a lot of very different things depending on context. In the context of a competition held at a computer security conference like LayerOne 2019 this past weekend, I found a technically oriented online digital scavenger hunt. There is a list of challenges, each of which starts with a clue that will lead the intrepid hunter towards an answer (“flag”) that can be submitted to increase their score.

What does it take to solve a challenge? Well, that’s entirely up to the organizers who can devise problems as simple and as difficult as they wished. I attended LayerOne last year though I did not participate in last year’s CTF. What I found everywhere else at LayerOne was a fun mix of activities that start with very beginner-friendly introductions that then climb steeply to still offer a challenge to longtime veterans.

It turns out their CTF is no different. There was one very beginner-friendly challenge — it was literally a reward for reading the hint and following instructions, no technical knowledge required. [Emily] was initially intimidated but quickly contributed by employing investigation skills from her journalism background. Thanks to her skills, our CTF team did not finish dead last.

To keep things on a friendly basis of competition, the targets of investigation are explicitly listed. A security challenge of “there’s a vulnerable computer somewhere nearby, find it.” might be interesting, but a bad idea to encourage probing every computer online. It would harm other conference attendees not participating in the CTF, it would be bad for hotel infrastructure and even other guests at the hotel.

While it is possible to just have a list of computer skill challenges in a CTF, organizers usually put in a little more effort to build around a theme. This year’s LayerOne CTF was about Star Trek. From the narratives presented as clues in many challenges, down to the LCARS style user interface of the main site. While we didn’t get very far in our CTF attempt, I appreciate the effort of organizers to engage beginners. Perhaps we’ll be better equipped the next time we come across one.

Sawppy at SCaLE 17x: The Trouble with Rovers

My primary obligation for Southern California Linux Expo (SCaLE 17x) was to co-present The Trouble with Rovers with Lan Dang on Saturday afternoon. Which meant when Sawppy’s coupler broke Friday evening I had to scramble to fix it for Saturday. A rush repair job is always going to leave some details to be desired but it was sufficient to resume operation.

Sawppy will obviously be one of the visual aids present at our talk, but that doesn’t mean it gets to spend the rest of the day just sitting around. No sir, as soon as Sawppy arrived on location, it immediately started working as a roving billboard for both itself and the talk.

Sawppy Scale 17x Sat 1 - Roving billboard

It was not explicitly coordinated beforehand, but the SGVHAK rover was also equipped with advertising for our talk. Both of our rovers were out and about, pulling roving billboard duty, and occasionally our paths crossed in the hallways of SCaLE.

Sawppy Scale 17x Sat 2 - Two roving billboards

I was happy with the turnout for our rover session. While we did lose a few people who left partway through the talk, it was more than made up for by the enthusiastic people who followed along and came up to ask questions after. I had a lot of fun explaining details on what we did for both rovers, minutiae that we trimmed from the talk proper but was still interesting to our smaller and more technical audience afterwards.

Sawppy Scale 17x Sat 3 - Session

Sawppy continued to roam around Pasadena Convention Center, spreading word of my rover project to people who are excited about the possibility of building their own. Some people thought it would be their motivation to finally buy their own 3D printer, others have all the tools on hand and it’s just a matter of prioritization and finding project time. I was most gratified by a group of students from California State University San Bernardino who thinks it would be a great group project. They are exactly the target audience!

And it’s fun as always to see young children’s faces light up when they see Sawppy, some of whom were eager to take control. My favorite was this 6-year old who loved to drive Sawppy over his own toes over and over.

Sawppy Scale 17x Sat 4 - Self foot runover

(Cross-posted to

Sawppy and SGVHAK Rover will be at SCaLE 17x

This year’s Southern California Linux Expo (SCaLE 17x) begins today. Four days of talks across multiple tracks focusing on topics relating to the flagship open source operating system in various ways. From small micro controllers to large cloud infrastructure. Last year’s SCaLE served as deadline and motivation for completing SGVHAK Rover, but it was only for purposes of show and tell. We couldn’t yet do a full presentation as the JPL Open Source Rover project has yet to officially launch until mid year.

But that is no longer a concern, and we even have spinoff projects like my Sawppy rover to add to the mix. Hence Sawppy will be part of our SGVHAK presentation “The Trouble with Rovers“: they’re never really finished, and their numbers keep growing. Rovers are such cool projects to work on there’s always more upgrades and evolution we can perform to make our rovers better. Lan and I practiced this talk at last month’s SGVLUG meetup and hopefully our presentation will be better for it! We’ll be presenting Saturday afternoon 4:30-5:30pm in Ballroom G.

20190214 Rovers at SGVLUG

Sawppy will also be present at the Tindie+Hackaday Bring-a-Hack meetup, under their “Birds of a Feather” event umbrella for groups to get a space and meet. It is a free event (with at least a SCaLE Expo Pass) and Sawppy will be there as representative of one of the projects with a page on This will take place Friday evening 7pm-8pm in Ballroom B.

Beyond those events, Sawppy will be generally hanging out and cruising about the event and the expo floor. There’ll probably be some time spent at the SGVLUG/SGVHAK booth, but no official scheduled events beyond the two above.

(Cross-posted to

W6TRW Amateur Radio Club Swap Meet

This week I revisited 23b shop on a day when they weren’t hosting Sparklecon, during one of their regular Thursday evening meets. I brought my Neato robot vacuum work in progress as my project and it was a good discussion icebreaker with a few of the people present. One of the interesting things I learned was the W6TRW Amateur Radio Club Swap Meet – officially a place for people to meet and trade amateur radio equipment, it has evolved into a place to find generally interesting electronics stuff to hack on. Some people were going to go shopping, and extended an invitation to join them.

W6TRW amateur radio club swap meet

I was not a huge fan of waking up early weekend morning to brave the cold outdoors, but the guys sold me on how cool the place enough to get me out of bed at 6 in the morning. I only had twenty-four dollars of cash in my wallet, and I thought that would make sure I don’t get myself into too much trouble.

Portable Karaoke duet machineFirst of all, the promise of seeing strange things I never even knew existed was fulfilled in spades, products aimed at novel niches that I had been completely clueless about. One example: this is a portable Karaoke machine that can run off batteries and use cassette tape for music, but this is a duet machine with two microphones for you and your singing partner to maintain eye contact while you sing everlasting love to each other. I don’t Karaoke and I was fascinated there was enough demand for this product to exist.

Bowling video game with ball controllerI also stumbled across this product: a bowling video game with a custom controller shaped like a bowling ball. If I understand XaviX’s Wikipedia entry correctly, this was much like Nintendo’s Wii Bowling but came out before the Nintendo Wii did. Sadly first-mover advantage in the motion controller home gaming market did not translate into market success for this company. Or even name recognition – I consider myself decently informed in video gaming trends and I had no idea these guys existed.

Old test equipment in cardboard boxes.jpg

Closer to the original spirit of the event, old electronics equipment abound, showing signs of a full service life that started as expensive specialized equipment and now sitting in cardboard boxes looking for a new home. Since I had just $24, I was not remotely tempted to take any of these big heavy metal boxes home.

I spent my money on more modest items that had immediate use for current projects. To help me see fine details for soldering and (dis)assembly, I bought a magnifier. To help me make finer details in my circuit sculpting, I bought a smaller pair of round-nosed pliers. And finally, in an effort to build my own substitute charging dock for my thrift store Neato robot vacuum, I picked up two 120V AC to 24V DC adapters. That accounted for all $24 dollars of cash I walked in with!

SGVHAK Rover, Sawppy, and Phoebe at SGVLUG February 2019 Meeting

At the February 2019 meet for San Gabriel Valley Linux User’s Group (SGVLUG), Lan and I presented the story of rover building in our hardware hackers spinoff group a.k.a. SGVHAK. This is a practice run for our presentation at Southern California Linux Expo (SCaLE) in March. Naturally, the rovers themselves had to be present as visual aids.

20190214 Rovers at SGVLUG

We started the story in January 2018, when Lan gathered the SGVHAK group to serve as beta testers for Jet Propulsion Laboratory’s Open Source Rover project. Then we went through our construction process, which was greatly motivated by our desire to have SGVHAK rover up and running at least year’s SCaLE. Having a rover at SCaLE was not the end, it was only the beginning. I started building my own rover Sawppy, and SGVHAK rover continued to pick up hardware upgrades along the way.

On the software side, we have ambition to increase sophistication by adapting the open source Robot Operation System (ROS) which led to a small digression to Phoebe, my tool for learning ROS. Getting a rover to work effectively under ROS poses some significant challenges that we have yet to address, but if it was easy it wouldn’t be fun!

Since this was a practice talk, the Q&A session at the end was also a forum for feedback on how we could improve the talk for SCaLE. We had some good suggestions on how we might have a better smoother narrative through the story, and we’ll see what we can figure out by March.

Sawppy at Brawerman East STEAM Makers Fair

Sawppy’s publicity appearance today was at Brawerman East STEAM Makers Fair, a supercharged science fair at a private elementary school. Sawppy earned this invitation by the way of January presentation at Robotics Society of Southern California. The intent is to show students that building things is more than their assignments at their on campus Innovation Lab, there are bigger projects they can strive for beyond the classroom. But the format is, indeed, just like a school science fair, where Sawppy got a display table and a poster board.

Brawerman STEAM Makers Fair - Sawppy on table

But Sawppy is not very interesting sitting on a table, it didn’t take long before the rover started roving amongst other exhibits. The school’s 3D printer is visible on the left – a Zortrax M200.

Brawerman STEAM Makers Fair - Sawppy roaming

Sawppy was not the only project from grown-ups present. I admire the ambition of this laser cutter project undertaken by one of the parents. Look at the size of that thing. It is currently a work in progress, and its incomplete wiring were completely removed for this event so little fingers are not tempted to unplug things and possibly plugging them in a wrong place.

Brawerman STEAM Makers Fair - laser cutter

The center of this tables had some old retired electronics equipment that kids will be able to take apart. This was a huge hit at the event, but by the end of the night this side of the room was a huge mess of tiny plastic pieces scattered all over.

Brawerman STEAM Makers Fair - deconstruction zone

I brought my iPad with the idea I could have Sawppy’s Onshape CAD data visible for browsing, but it turned out the iOS Onshape app required a live internet connection and refused to work from cache. As an alternate activity, I rigged it up to show live video footage from Sawppy’s onboard camera. This was surprisingly popular with the elementary school age crowd, who got a kick out of making faces at the camera and seeing their faces on the iPad. I need to remember to do this for future Sawppy outings.

Brawerman STEAM Makers Fair - Sawppy camera ipad

After Sawppy was already committed to the event, I learned that a Star Wars themed art car was also going to be present. So I mentioned my #rxbb8 project which earned me a prime parking spot on the first floor next to the far more extensively modified “Z-Wing.” Prepare to jump to hyperspace!


(Cross-posted to

Sawppy at Space Carnival Long Beach

Sawppy at Space Carnival Long Beach

Space Carnival, held at the Expo Arts Center in Long Beach, California, welcomed Sawppy as one of several exhibits Monday afternoon. It turned out to be part of a week-long LEGO robotics camp for elementary school students. Most of the events are for campers, but the Monday evening Space Carnival was open to the public.

Since the focus is on LEGO, there were plenty of plastic bricks in attendance. The middle of the room had a big pile of bricks on a plastic tarp and kids were crawling all over the pile building their creations. Sawppy mostly spent time outside of the tarp, occasionally venturing on to some of the colorful game boards for LEGO robots to line-follow and other tasks.

Sawppy at Space Carnival Long Beach LEGO tarp

As usual, I handed controls over for kids in attendance to play with. Running over feet is still more popular of an event than I can hope to understand but, if it makes them excited, so be it.

Sawppy at Space Carnival Long Beach running over feet

Sawppy was not the only non-LEGO robot in attendance, there were also a selection of Star Wars licensed merchandise including this R2D2. I forgot if this particular unit was made by Sphero or Hasbro.

Sawppy at Space Carnival Long Beach R2D2

This event was not the first time I crossed paths with Barnabas Robotics, but it was the first time I got to speak with them beyond the standard sales pitch type of discussions. Since their business is STEM education for students K-12, they have a good feel of what type of material is appropriate for various age groups. It’s possible Sawppy can find a role in high school curriculum.

At the end of the night, the LEGO tarp cleared out enough for me to drive Sawppy across the field. Unfortunately I saw Emily’s tweet too late to replicate the movie clip she had suggested. Maybe another day!

(Cross-posted to

My Monoprice 3D Printers at February 2019 RSSC Meeting

When I presented the story of my Sawppy rover project last month at the January 2019 meet of Robotics Society of Southern California (RSSC) I made an offhand comment about my 3D printers. Later on, in a discussion on potential speakers, there were people who wanted to know more about 3D printers and I offered to summarize my 3D printer experience in a follow-on talk. Originally scheduled for March, I asked to be rescheduled when I realized the March RSSC meet would take place at the same time as Southern California Linux Expo (SCaLE).

My talk (presentation slide deck) starts with a disclaimer that my experience and knowledge was limited. I started by explaining why I chose Monoprice printers backed by a short history lesson on Monoprice because that sets the proper expectations. Then I ran through my three Monoprice printers: the Select Mini, the Maker Select V2, and the Maker Ultimate. Each of these printers had their strengths and weaknesses.

Monoprice Select Mini

  • Simple low-cost printer that still covers all the basic concepts of FDM printers.
  • Closest we have to a “Fisher Price My First 3D Printer”
  • Recommended for beginners to find out if they’ll like 3D printing.

Monoprice Maker Select

  • Classic Prusa i3 design.
  • Easiest to take apart for modifications and/or repairs.
  • Recommended for people who like to tinker with their equipment.

Monoprice Maker Ultimate

  • Design “inspired by” Ultimaker.
  • Highest precision and most reliable operation.
  • Recommended for people who just want their equipment to work.
  • But price level approaches that of many other good printers, like a genuine Prusa i3.

I brought my printers to the meet so interested people can look them over up close. I did not perform any print demos, because I’ve almost certainly knocked the beds out of level during transit. Plus, I forgot my spools of filament at home. But these are robotics people, they can gain a lot just by looking over the mechanical bits.

SparkleCon Sidetrack: Does It Have A Name?

spool holder with two stage straightener 1600x1200

My simple afternoon hack of a copper wire straightener got more attention – both online and off – than I had expected. One of these came as a fun sidetrack to my Sparklecon talk about my KISS Tindie wire sculptures. As part of the background on my wire form project, I mentioned creating this holder. It kicked off a few questions, which I had answered, but I had the most fun with “Does it have a name?”

I gave the actual answer first, which was that I had only been calling it a very straightforward “wire spool holder with straightener” but I followed it up with an off-the-cuff joke “Or did you mean a name like Felicia?” I think I saw a smile by the person asking the question (hard to tell, he had a beard) and I also got a few laughs out of the audience which is great. I had intended to leave it at that, but as I was returning to my presentation another joke occurred to me: “Felicia will set you straight.”

Since my script was already derailed, I saw no reason to run with it: “Is there a fictional character who is a disciplinarian? That might be fitting.” and opened it up to the audience for suggestions. We got “Mary Poppins” which isn’t bad, but things went downhill from there. The fact is: the disciplinarian in a story is almost always a killjoy obstacle in our hero’s journey. Or worse, one of the villains, as in the suggestion of “Delores Umbridge” given by a woman wearing a Harry Potter shirt. My reaction was immediate: “No.” But two seconds later I remembered to make it a tad more positive: “Thank you, she is indeed a disciplinarian, but no.” Hopefully she doesn’t feel like I bit her head off.

After the talk, there were additional suggestions interpreting my second joke “Felicia will set you straight” in the sense of personal relationship preferences. This went down a path of politically conservative zealots who believe it is their public duty to dictate what people do in private. This direction of thinking never even occurred to me when I threw out the joke on a whim.

I think I’ll leave it at Mary Poppins.