Companion Robots and Maker Faire Season!

Posted on September 23, 2023 by Maker Block

I’m super excited for Maker Faire Bay Area / Mare Island and ~~Mini~~ Maker Faire Rocklin.1 I’m not just excited to see everything, but to show all the things I’ve been working on for a while now. It’s also time to pick up all the little dev boards I’ve somehow accumulated and see if I can make anything with them to show off.

Project Boards
1. Wemos D1 Mini. A small insanely cheap (~$3?!) WiFi enabled dev board2 , which has 4MB onboard and can run Arduino. I think it can also run MicroPython, but I haven’t tested this yet.
2. Wemos 600 Pico. An even smaller, even cheaper (~$2 when ordered from China) WiFi enabled dev board that runs… MicroPython? I think?? I’m saying “I think” because I haven’t been able to get it to do anything yet.
  1. Since starting this blog post, I found a guide on installing MicroPython on Wemos boards that seems promising.
    1. Flashing MicroPython on an ESP8266
    2. https://github.com/espressif/esptool/tree/master
    3. Arguing with Python to let me use “esptool.py”
      1. esptool -p COM13 -c esp8266 flash_id
  2. As promising as that series of blog posts looked, I eventually scrapped the Wemos because it was just too much of a pain to get going with MicroPython. I think I could have made it work, but for $7 I could also just use the Adafruit QtPy I already have. The advantages of simply uploading code over a USB cable into a virtual drive just can’t be overstated.
3. Other Boards
  1. I have a bad habit of picking up dev boards. I’ve got several Adafruit QtPy’s, several Adafruit Trinkets, an Adafruit FX Sound Board, Raspberry Pi Pico (non-WiFi), various Digispark boards, a small handful of ATTiny85’s, and an even weirder assortment of VERY small programmable circuit boards (ISD1806B-COB) designed to go in greeting cards (just 6 seconds), etc.
Companion Robot
1. Background.
  1. I started this post at least a month ago when I only had a vague idea of what I wanted to make and even fewer skills. After seeing my kid’s companion robot take shape, I wanted to get in on the action and make my own. I decided to make a really small companion robot with just some LED’s, piezo, and small microcontroller unit. I’d taken a stab at making a companion robot a few years ago, but set it aside for a variety of reasons and never went back.
  2. The idea for this new robot would be something a little less ambitious, make more use of NeoPixels than in prior projects3, with a little more interactivity, trying out some CircuitPython, and… let’s be real… more pizzazz!
2. Idea: Friendly Cloud/Vapor/Flame
  1. I still really like the copper-toned PLA I’ve been using since it has something of a steampunk flair to it. I settled on repurposing a small plastic enclosure with a clear dome as the “body” for the robot. I wanted it to look something like a small entrapped / captive / domesticated4 sentient cloud of vapor or perhaps flame held within a steampunk enclosure.
  2. As a very small, inexpensive board that could run either Arduino or Circuit Python, I decided on the Adafruit QtPy M0. It could run NeoPixels, there were lots of cool guides on it, plenty of pinouts, and could definitely fit within the confines of my enclosure.
3. Enclosure:
  1. I started the enclosure by trying to design and 3D print a part to mate with the clear plastic dome. It took a few tries.
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  2. Once I had that, I extended the base so it could hold more electronics. I could definitely have shoehorned everything into the dome, especially if I took up some of the space inside the dome, but even with an “elevated base” it was still plenty small and could use a battery pack rather than a rechargeable lipo.
  3. Once I had a good design for the enclosure, I tried to make it work with an existing 3xAAA battery pack. In the process I yanked off the connector and ended up soldering the battery pack leads directly into the circuits.
4. Internal Electronics
  1. I’m just not a great electrical engineer and am still copy/pasting from various guides, tinkering, changing bits of code, swapping out parts, and using “close enough” resistors. Wiring up some LEDs or a piezo to a project isn’t very difficult – it’s some of the more fiddly bits.
  2. Piezo Element Speaker
    1. I wanted to use a piezo buzzer/speaker because they’re large and incredibly thin. They’re not without their downsides. The crystal wafer is also thin and a little fragile. The piezo buzzer without additional electronics has the potential to act as a knock sensor and can generate a high voltage spike which can fry a board. And, without additional electronics, the piezo just isn’t very loud. There are some libraries for the Arduino that basically double the volume of a piezo by connecting it to two pins and then running each opposite of the other, doubling the voltage difference, but they only work for Arduino chips.5
    2. After searching for various ways to increase the sound of the piezo elements, I settled on trying to use the Adafruit piezo amp. I bought two – and tried desoldering the terminal blocks. This completely ruined one. The other one worked great, but for the modest volume gain it was just too big in an already cramped enclosure.
    3. After searching around, I found some amplifier circuits using a small number of common parts.6
    4. Then I tried building an amplifier circuit using an NPN transistor. After reviewing the datasheets for my NPN transistors (and PNP transistors), and breadboarding the circuit with resistors, I sketched it a few times, laid it down with copper tape, soldered it in place with SMD resistors, then pulled it off and placed it onto a piece of Kapton tape and put another piece on top – “laminating” it in place.
  3. Capacitive Touch
    1. Buttons are great and all, but with a capacitive touch pad, I could add metallic elements to my robot rather than a much bulkier button. I bought a few brass upholstery tacks because they looked great – but they just would not accept molten solder. I ended up cutting the prongs short with wire cutters, wrapping the stub with copper tape, then soldering the wires to the tape. I’d also added a little piece of heat shrink tubing over the connection to help keep it together. It’s been working well so far.
  4. LED Animations
    1. As we know from Phillip Burgess‘ incredible “power sipping NeoPixel” guide, we can conserve power and increase the impact of the LED’s by reducing the number of LED’s, keeping max brightness ~20% for a disproportionately large impact, running fewer LED’s at a time, and even running fewer colors at a time. Between Phillip’s work, Todbot’s guide, and the specialized QtPy NeoPixel guide by Kattni Rembor, I was able to put together a few neat animations.
  5. Piezo Sounds
    1. I had a heck of time getting the piezo buzzer to do anything interesting. Fortunately, with my kid helped convert the piano music for “Paint It Black” into tones for me. I haven’t gotten all the note timings right, but I’m working on it!
Future Modifications
1. More Accessible Enclosure. Right now the “lid” with a hole for the LED ring just sits on the enclosure with a light friction fit. One idea is a hinged lid, either with a conventional hinge or perhaps a hidden swivel hinge. The problem with that, of course, is it requires even more internal space. Other ideas include a ring on top that screws down, holding the top down and in place. I’m crap at designing screw threads, so I’ve avoided this.
  Hinged lid for enclosure
2. Piezo Knocks. Perhaps the next version will include some kind of tap / double tap / knock sensors using one or more piezo elements.
3. Knobs. There’s not a ton of room inside the enclosure, but by including a gear within a gear, I might be able to rotate part of the case and have it manipulate a potentiometer.
  Offset gear within gear, manipulating an off-center internal potentiometer
4. Motors. A robot that just flashes lights and makes a few beeps can still be pretty interesting. However, I have some neat potential features that could be added with just one or two motors. There are some interesting limitations with the current incarnation of this robot and using a QtPy. I’ve only got 10 pinouts7 , 1 for NeoPixels, 1 for the piezo, 6 in use for the capacitive touch sensors, leaving 2 for other potential tasks.8 However, space is already tight so one or two micro servos would be a big space commitment. I’ve seen some really tiny micro servos that might work, but I have no idea where to source them. One silly idea is a “weapons system” using a spring loaded projectile activated by a very small servo.
  A small spring loaded projectile launcher, actuated by a small servo
5. Creating Tone Library. The basic piezo tones are easy enough to play, but including the entire list of tones and the frequencies associated with them seems eat up the poor little QtPy’s memory. I think compressing them into a library might be the way around this issue.
6. Playing WAV files. WAV files are bulky, but that’s the only sound file format a QtPy M0 can play. However, with the extra 2MB from the SPI chip installed, this shouldn’t be a huge problem. I used Audacity to mix the sound clip down to mono then to 22 KHz sample rate. My preliminary tests worked – but it was incredibly quiet. I haven’t run it through the audio amplifier yet, but I’m planning to.
7. Sleep / Deep Sleep. Ever since I swapped out the tiny LiPo for a 3xAAA battery pack, I’ve had a lot more battery life, so adding sleep / deep sleep functions haven’t been a priority. However, this inclusion just couldn’t hurt.
Other QtPy and CircuitPython Resources
1. Adafruit’s QtPy CircuitPython PWM resource
2. TodBot’s CircuitPython tricks

Companion Robots: Building Robot Friends

I just got a notice they’re no longer a “Mini”! [↩]
pinouts for my future reference [↩]
LED goggles and a Marvel Universe inspired set of “Infinity Knuckles” [↩]
OMG dome-sticated?! [↩]
This is just my very basic understanding of how it works. I’m entirely positive this is far too simplified. [↩]
And one very long article about using a lot of parts [↩]
12 if you want to count the onboard NeoPixel [↩]
Or 4… [↩]

Beep Boop: Emotions for ED-E

Posted on August 14, 2023 by Dexter Zoltron

So I’m trying to program emotions for ED-E.

Better ed-e dialogue at Fallout New Vegas - mods and community

In Fallout New Vegas, ED-E doesn’t use regular dialogue, but communicates through beeps. Basically, he gets <(Emotion) + beeping> as his dialogue. Obviously the only way to research his beeping for this project is to replay Fallout New Vegas and talk to everyone’s favorite eyebot. I came up with a list of some of the emotional beeps he has in the game (and some that I just want) to start programming into him. I have ideas for what I want him to sound like, but I just need to find the right pitches and durations.

By this I mean I am sitting in my room and saying “beep beep” to myself at different pitches in sync with a program I wrote.

Yesterday my dad was checking in on me and how my programming was going and asked how I was doing. I replied, approximately, “bleurrrrghhhhh.”

I was having trouble programming the emotional beeps because I have very specific ideas for what ED-E should sound like and no way to get that into a computer. I’m a huge music nerd, but I unfortunately don’t have perfect pitch or some superhuman ability like that to use to get ED-E to sound exactly like I want him to.1 Dad suggested using a loop with an array going up every time, which made everything so. Much. Easier.

This plays frequencies starting at 100hz and going up by 10hz every time. I started with 100hz but going up by 50hz every time, but I liked the specificity of 10hz. Once I get in the ballpark of where I want to be, I can then just run the program and correct the pitches if need be.

If you read my last post, specifically the spoiler section, you will know why I started with a shy beep. If you didn’t read my last post, go do that! If you didn’t read the spoiler section, that’s fine. What you really need to know is that I want ED-E to make noises.

I’ll admit, this took a while to get right. Not playing the tones or even figuring out what pitches they were or how long they should play for. No, getting the tones to play was easy. Getting them to stop… was much harder.

ED-E was shyly screaming at me on repeat for at least 10 minutes while I was slowly losing my mind and trying to make him shut up.

I turned to ChatGPT to help me fix this, but it was utterly unhelpful and I ended up fixing the problem myself by deleting a bunch of the garbage it generated. Now the problem was that I had to continually upload the code to make the ShyBeep function run again. I was happy that it wasn’t looping anymore, but I wanted to fine tune the beeps and making it upload again and again was a pain. That’s why I decided to make it run when a button is pressed.2

It took a little while to make it run when a button was pressed, but then it would only run once and never again, even if the button was pressed. I finally realized that this was happening because runOnce was set to false, and fixed that.

Now that I have this framework, it has been much easier to program more beeps. Now I have a sad beep, and I’m going to start working on a happy beep because I have had just about enough of ED-E’s negativity.3

ED-E Companion Bot Project

I almost decided to use the definitions of pitch from my Rickroll code so I could just ask the computer to start at middle C and go down or say I want the pitch to be a half note in 3/4 time. I then realized I was making this WAY more complicated than it needed to be and just used seconds and hz like a normal-ish person [↩]
I seriously love Circuit Playgrounds. They have everything. [↩]
Just kidding ED-E, I love you [↩]

ED-E Project: Origins

Posted on August 13, 2023 by Dexter Zoltron

Hi, I’m DexterStarfighter, offspring of MakerBlock.1 I am a maker and artist with possibly too many interests that include drawing, writing, cats, theatre, video games, horror podcasts, folklore, coding, Jenga, history, triangles, succulents, and reading literally anything. I have been going to MakerFaire for basically my entire life and it has always been something I look forward to for the whole year. As soon as Dad told me MakerFaire was coming back, I knew I had to make something super cool for the occasion. This brings me to my latest project, a companion robot.

First, some background. My favorite game is part of the Fallout series (New Vegas, if you were wondering). I started the Fallout series because my dad played them when the first Fallout came out and I wanted to be able to share a cool game with him. I started Fallout 1 and loved it, then played Fallout 2 and 3. Over the summer, Epic Games released Fallout New Vegas with all DLCs for free and of course, I played the crap out of that.2 3

In Fallout New Vegas, there are various companions you can take with you on your journey through the Wasteland. There are human companions of course (and ghoul and nightkin), but you can also take with you one nonhuman companion. At first I was super disappointed that I couldn’t find Dogmeat. I don’t actually like being around dogs in real life, but I got Dogmeat in Fallout 1 and somehow I have become very attached. (I do not even want to think about how many times I have reloaded a save to keep that little jerk alive.) I quickly got over my disappointment though, because there is a statue of a dinosaur and now I’m disappointed that you can’t have a dinosaur robot companion. Anyway, in my travels through the Mojave, I found two interesting nonhuman companions. The first one I found was this little eye bot named ED-E. I play as a charismatic nerd (high INT and CHA with good repair, speech, barter and science) so I was able to fix him up. ED-E was still only able to beep in ways I couldn’t understand and when I brought him to where I was supposed to for his quest, there was some sort of glitch and I couldn’t interact with the lady for the quest. ED-E seemed kind of lame to me then, so I took him back to the place I found him and left. I later ran into a dog named Rex who I had to take care of for an Elvis impersonator (no, really) and found he was a pretty good companion.

Flash forward to the endgame. I had met a cowboy robot, climbed a dinosaur statue, resurrected a B-29, fought a soldier for a dog’s brain, charmed a scientist, accidentally sided with the mafia, cleaned out an entire casino, assassinated a 261-year-old man, had my vital organs removed, stolen 27 bars of gold, befriended a man wrapped in toilet paper, and was well on my way to conquering New Vegas for myself. I had only one more thing to check off my list: walking the Courier’s Mile. Don’t worry, I won’t spoil the Lonesome Road quest for you- I’ll just tell you that I met ED-E again. Somehow, within the first few minutes of interacting with him, I had become so completely charmed by this little robot that I would do literally anything to protect him. I’m not sure what about ED-E made him so endearing to me, but he became my best friend.

GameBanshee

In 2019, I met Odd_Jayy at MakerFaire. I remember seeing his spider bot and thinking how cool it was. I’ve always liked the idea of a companion bot, but I’ve never actually had a specific idea of what I want out of one. When dad told me that we would be going to MakerFaire again, I immediately thought of an ED-E companion bot.4 Dad loved the idea too and gave me lots of good tips on how to get started. I have a tendency to get lost in the details, so he helped me focus on the big picture and the first steps I could take to achieving my goals.

I have a lot of ideas about what I want ED-E to do eventually, but I’m a complete beginner at Arduino programming. Knowing this, Dad suggested starting small. First, turn on one light. Then multiple lights. Then make them flash. Then make them change colors. Then add beeps. Stuff like that. I was like “cool, cool” and immediately programmed ED-E to beep the entirety of Never Gonna Give You Up instead of doing literally anything sensible.

I regret nothing. It was frustrating at first because I was super out of my depth. I used Chlorondria’s arrangement of Never Gonna Give You Up and used ChatGPT to help me learn how the code works. ChatGPT was super helpful because I could get feedback on why my code wasn’t working. The sense of accomplishment when I finally recognized the tune made all the frustration so incredibly worth it.

After my self-indulgent first project for ED-E, I moved on to taking Dad’s suggestions. Sort of. I’m a teenager, and therefore I am legally obliged not to listen to any authority figures, real or perceived. I made ED-E flash some rainbow lights. I started with just red lights and it took a while to make the code work, but once I made it work, I just changed the color brightnesses. Fun fact: my ED-E bot now actually glows two shades of blue in his rainbow light show pattern. For some reason I decided RGB stood for Red Yellow Blue and messed up with the color values when I was trying to make green and accidentally made a light blue. The light blue actually looked pretty cool, so I decided to keep it.

Today, I worked more on5 ED-E’s… musical function. I’m going to warn you right now: there will be spoilers for MakerFaire below! I intend to take ED-E to MakerFaire with me, and if you meet him, there will be some fun surprises in store for you. Not if you read the spoilers, though. MakerFaire is a big place and I don’t expect everyone who visits this page to run into me at the Faire, so I’ll include some stuff about the surprises below.

***SPOILERS START***

If you’re still here, I assume you want to read this. One of my favorite things about ED-E in Fallout are the little conversations you can have with him. I want to be able to have a few little “conversations” with my companion bot, kind of like in the game. I’m going to have a Pip-Boy with various buttons to run functions for ED-E, but one of the first conversations I thought of had to do with his musical function. This was my idea:

Me: Hey, ED-E. Do you wanna sing them your favorite song?

ED-E: [Shy beeping]

Me: Aw, are you shy?

ED-E: [Shy beeping]

Me: Come on, ED-E. We’d all really like to hear you sing!

ED-E: [Questioning beeping]

Me: Yes, of course! Listen, I’ll ask them. Do you want to hear ED-E sing his favorite song?

Other person: Yes!

Me: See, ED-E?

ED-E: [Pleased beeps, wait, then Rickroll beeps]

Obviously, I’m not going to make ED-E understand my words and respond to them. ED-E will be a shoulder mounted bot, so I want to be able to have conversations that trigger based on movement. I’m using a Circuit Playground, so I intend to take full advantage of all the different sensors it has. I programmed ED-E to run his Rickroll function if he senses a significant change in acceleration. I’ll pop my shoulder like I’m giving him a nudge, triggering the function. He waits for 8 seconds to give me time to talk, then plays the Rickroll beeps.

I have to admit, this took a WHILE to get right. It was still incredibly satisfying to see it all come together and go right. I was so excited when it started working! I did a lot of testing to get the sensitivity right because I don’t want it to trigger if I’m just walking around. I’m still fine tuning that part because I bumped the cord earlier and he started Rickrolling me. Then again, maybe ED-E just has a funny sense of humor.

***SPOILERS END***

So, what’s next for ED-E? I think the next thing I want to work on is getting his beeps right. I can make him beep music, and that’s great, but I also want to have him beep every so often and have “conversations” with him. I’m going to program some little beep clips for different emotions or situations that I can then mix and match into various conversations. I might also actually listen to Dad for once and work on a light show.

Thanks for reading about my ED-E project! I’ve enjoyed working on him and I’m so excited to share him with other makers. I’ll try to post updates regularly (they shouldn’t be as long as this one since you won’t need all the background next time). Thank you to Odd_Jayy for the inspiration, Chlorondria for the musical arrangement, ChatGPT for the troubleshooting help, Adafruit for making awesome boards, whoever made Fallout New Vegas, MakerBlock for being a great dad and helpful sounding board, and to you for reading this post.

ED-E Companion Bot Project

I considered saying progeny and descendant of the House of MakerBlock, but offspring sounded the best. Progeny sounded weird and the descendant thing reminded me of Game of Thrones, which I have not read or watched, but I might someday and I don’t want to invite spoilers. [↩]
I love Epic Games. Free games every week? Yes please! Disclaimer: I am not being sponsored by Epic Games, but if I was, that would be awesome. [↩]
New Vegas is best Fallout, you can fight me on this. [↩]
I also considered a Muggy companion bot. I love Muggy and if ED-E turns out well, Muggy might be my next project. [↩]
Lol, moron [↩]

Building the Monocle Top Hat Cat for #MicrobitVirtualConcert

Posted on May 22, 2021 by Maker Block

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The last few months there have been some pretty amazing little robots posted online for the Tinkering Studio / Exploratorium #MicrobitVirtualConcert. I wanted to make something and participate and my 6 year old was interested in helping out. I don’t have a Micro:Bit, but I’ve got a few other microcontrollers and the Adafruit Circuitplayground Express is perfect for this kind of project.

Here was our basic process:

Brainstorm ideas
I eat a frozen pizza and save the cardboard
Sketch of robot – and what it should do
Taping sketch of robot over white cardboard
Tracing sketch with a pencil with enough pressure to leave an indentation
Coloring robot
Measuring / designing a 3D printed plastic part to fit the servo (before I committed more plastic to it)
Scratching my head and jamming together circuitpython code for servos and musical notes together. I had really wanted to also have the eyes light up with Neopixels too, but…
Ultimately, I had a sketch for lights + musical tones and another for servo + musical tones. My daughter made the executive decision to go with servo + musical tones. 1
Revising the design to include some “wings” for more surface area to glue to the card board and increase stability
Adding extra “wings” so that the popsicle sticks could pivot on a piece of paperclip in the plastic holder, rather than in the cardboard
“Drilling” holes in the popsicle sticks with drill bits rotated by hand
Gluing in servo holder and just lashing bits of things together in the back with hot glue, blue tape, and some wire
Testing different kinds of tails before gluing the final version in place
The code and STL’s aren’t anything amazing and I didn’t do a lot to comment them. However, if you might find them useful, I’ve uploaded them to PrusaPrinters.

Here’s the final robot in action:

Companion Robots: Building Robot Friends

What can I say? In order to bring her onto the project, I had to agree to give her final cut. [↩]

An Assembled CuttleBot Body

Posted on June 24, 2019 by Maker Block

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It’s one thing to hack away in CAD software, rendering the idea of a model. It’s another thing entirely to pull it off the print bed and pop it all together.

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Last night before going to sleep I started the 2+ hour print job that became the center body piece for the CuttleBot. When I woke up in the middle of the night, I plucked it off the build platform, started the tail section printing (a 90 minute print job), and passed out again. This morning I printed 15 connector pins while getting ready for work.

Just before leaving for work, I yanked out the support structures using some needle nose pliers and popped it all together with the connector pins, and took some pictures to share with you, dear reader.

This was an incredibly satisfying result. Sometimes the work spent on something like the little pins and sockets feels so removed from the design of the main object – so very far from the goals. It feels similar to the work that goes into painting a house – you spend all this time NOT painting before you actually paint. Moving and covering furniture and decorations, taping and masking areas off, removing cabinets and doors. But, as long as I was able to keep my eye on the vision of the final model, laying that ground work on these components meant that I really could assemble a foot long plastic CuttleBot body in a few seconds.

Sigh. At this point, it kinda resembles a CyberMat more than a robotic cuttle fish.

I enjoy sketching out my ideas, so here’s one in case you like looking at them.

It’s NOT a CyberMat! It’s a robotic cuttlefish!

So, what’s left to do? A whole lot. I need to:

Design newer, thinner tentacles, so I can fit more into the CuttleBot’s head.
Hollow out the robot’s head or at least create channels for wiring for LED’s inside the eyes.
There needs to be some mounting areas inside the robot to secure one or two micro servo motors, a small circuit board, a battery, and possibly a few additional components.
Possibly create a door allow easy access to the interior of the robot. Once I start adding electronics, it might be great to have an on/off switch and nice to be able to connect a USB cable to it to recharge an internal battery or reprogram the behavior.
Add the electronics and program them.
1. This is probably two servos, several chained NeoPixel LED’s, a LiPo battery, an Adafruit Trinket, and possibly a LiPo charger (if I have one lying around).
2. If I’m already working towards building a new version anyhow, I might want to drop a few dollars on an OSHPark Board to help make the power from the LiPo easier to route to the servos, LED’s, and board.

However, I don’t think I’m going to be able to finish the robot before Friday.

I think I could probably manage blinking LED eyes by Friday.

Maybe.

Companion Robots: Building Robot Friends

CuttleBot Body and OpenSCAD Design Tips

Posted on June 23, 2019 by Maker Block

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I really like 3D printing – but really dislike post-processing. This means I’ll make extra efforts to design things that can just be plucked off the build platform and hand assembled without tools. With my limited build volume, this also means larger objects need to be printed in sections.

I’m very proud of a particular design method in the CuttleBot. I designed the organic and non-angular design of the CuttleBot body by using the “hull” function and several carefully deformed and positioned spheres. However, it would be very difficult to hollow out the interior – since it would mean designing another entire structure to be subtracted out. Instead of creating the outside shape I wanted and using difference to hollow the interior, I designed the interior shape and used that to create the exterior with the “minkowski” function.

Here’s an OpenSCAD code example:

difference()
    {
    //  Traces sphere around exterior of cube
    minkowski()
        {
        //  Main object
        cube(50, center=true);
        //  Object to trace around main object
        sphere(r=5);
        }
    //  Removing center of object
    cube(50, center=true);
    // Arbitrarily large cutout
    cube(10000, center=false);
    }

Minkowski sample

Although, now that I think about it, there’s probably an even cooler way to do this! Since the above code needs to refer to the “target” object twice, that code can be simplified by using the “children” function. The below code creates an identical shape.

hollowObject(5) cube(50, center=true);

module hollowObject(thickness)
    {
    difference()
        {
        minkowski()
            {
            children();
            sphere(r=thickness);
            }
        children();
        //  Arbitrarily large cutout
        cube(10000, center=false);
        }
    }

The great thing about a modeling process like this is it allows you to maintain an even thickness all the way around the model. This would be increasingly difficult as the complexity of the underlying model increases.

Lastly, to return to the model, after hollowing out the interior of the CuttleBot, I added areas for the pins to connect the sections together. The body of the robot is in three sections – the head, the mid-body, and the tail sections.

There’s still more to do on the model. Ideally, I’d create a way to open the robot without having to completely take it apart each time. A hinged door would work fine. Also, I should probably add an area where one or more micro servos could be zip-tied or otherwise secured in place. Also, I’ll need to modify the robot’s head later on to allow for multiple (smaller) tentacles and channels for adding wiring for LED’s to the eyes.

There’s also the whole “adding electronics” thing. You know, to make this less a puppet and more a robot.

Companion Robots: Building Robot Friends

Cephalopod Robot Friend Progress

Posted on June 21, 2019 by Maker Block

Well, it’s here! Today is the start of #CephalopodWeek on ScienceFriday! There’s a little progress to report on my, tentatively named, CuttleBot. I’ll post a picture first, then get to describing the progress so far.

Assembled CuttleBot head, side view

In the prior post I listed some of my sources of inspiration. Another such source is the work of Sean Charlesworth and his awesome Octopod, Gowanus Monster, and newly published Scuttleship. ((If you like his work, be sure and check out his Etsy shop!))

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Since I need special connectors for the articulated/articulating tentacles and I wasn’t able to edit the files in OpenSCAD, I wasn’t able to use Sean’s STL files. However, I really like the aesthetic of his designs1 and how they really evoke the form of an octopus or cuttlefish. Here’s a mock up I used to help me visualize what a full-scale Scuttlefish head might look like with the tentacles I designed.

Scuttlefish with placeholders for tentacles

Unfortunately, the Scuttlefish head and body parts are just a tad too large for my small printer’s build volume. However, even if I were using a larger printer, I would still not want such a large robot as I’m hoping for this to be a shoulder-mounted companion.

Thus, I began work creating an OpenSCAD cephalopod cuttlefish head inspired by Sean’s work.

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Now that I had a design, I set the printer to work over night. This design is mostly to see if the various parts for the tentacles would work with this head. Since I want to put some LED’s in the eyes and possibly the mouth, I’ll need to hollow it out later.

The print took a little over an hour for the head.

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How about a video of it working?

I’m very happy with the progress so far. If I can shrink down the tentacle mechanisms, I can add more tentacles for more interesting emoting and animations. The video just shows the results of me yanking the fishing line running through the CuttleBot’s head.

Here’s a few more sketches of how I am planning on putting it all together.

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I might add some fabric frills / fins, instead of printed ones. I was also contemplating letting the top “shell” of the CuttleBot be formed from 3D printed spines with a fabric or thin plastic sheeting covering. This might help reduce weight or allow for internal lights to shine through the body.

Companion Robots: Building Robot Friends

Cephalopod Steampunk?! [↩]

Cephalopod Robot Friend, the story so far

Posted on June 18, 2019 by Maker Block

Quick lead in: I am trying to build a cephalopod robot shoulder friend.

I was disappointed that I only learned of Glow Ascii‘s owl robot companion, Archimedes, after Maker Faire Bay Area 2018. Over the year, leading up to Maker Faire Bay Area 2019, I followed Odd_Jayy‘s spider/bowler Anansi robot companion with similar rapt interest.

Still high off Maker Faire 20191 , I was also excited by the prospect of #CephalopodWeek on NPR’s ScienceFriday. Between cuttlefish, squid, and various octopuses (especially the “Opisthoteuthis Adorabilis“), there are a LOT of awesome little friends to consider making.

While trying to avoid work, I posted a sketches to Twitter.

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Last week I started designing a few parts, drawing from some experience designing printable prosthetics for the E-nable project a few years ago. I was trying to build it out of what I had on hand, which did not include elastic cord. I thought a zip tie might provide enough “spring” and “give” to work.

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I admit, this was a total mess. I suppose it is only fitting I use this meme featuring Dr. Zoidberg.

Thanks Dr. Z

Thanks to some kind encouragement from Odd_Jayy, I kept moving forward. Rather than focusing on the end of the tentacle, I got to work on the basics of the mechanics – channels for the elastic cord and fishing line, wedges cut into the faces so the tentacle could articulate.

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The tabs on these parts were too thin and tended to break when I assembled them. However, the next version worked really well.

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These worked a lot better, so I started cranking out parts.

The nice thing about these tentacles is that they look somewhat lifelike without actually requiring much in the way of electronics. As long as I can design a body/housing and put a servo inside, that one servo could possibly pull on 8 different sets of fishing line to articulate all the tentacles at the same time. And, since it’s just fishing line, there’s no special routing of brake cables necessary.

The tentacles are somewhat larger than I would like, so that means where they connect to the body needs to be similarly large. There’s definitely room for improving the tentacle segments. I’ve already designed two different “ends” for the tentacles, so they’re rounded instead of exposed connectors, fishing line, and elastic cord. Also, to make the curling tentacle look better, I should angle the the top and bottom of each segment. Another improvement would be to rotate the articulation angle for different segments to give the tentacle a more organic look when moving.

However, if I don’t get working on the body of the robot, it’s not going to ever get done. Given the size of the tentacles, I’d need to have them all on one side, lest the little robot take over my entire shoulder. Here are some “Cuttle-Bot” sketches along with a robot body design. If you look at the design, you’ll notice the connectors are rotated to different angles. This is so that the tentacles would each spring back together towards each other – and then splay outwards when articulated.

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However, this last design takes FOREVER2 to render in OpenSCAD. This is at least partially due to design and code inefficiencies, but also due to the number of spherical parts, facets, and “hull” operations needed to make these parts work.

I think I may want to try shrinking the tentacles slightly so I can build a smaller-bodied robot. Either way, I have to get cracking on at least some kind of housing/body and mounting motors/electronics before I can keep moving forward.

Companion Robots: Building Robot Friends

LONG LIVE MAKER FAIRE! [↩]
Well, a little over 5 minutes [↩]

MakerBlock

And I, for one, welcome our new robotic overlords

Category Archives: Companion Robot

Companion Robots and Maker Faire Season!

Beep Boop: Emotions for ED-E

ED-E Project: Origins

Building the Monocle Top Hat Cat for #MicrobitVirtualConcert

An Assembled CuttleBot Body

CuttleBot Body and OpenSCAD Design Tips

Cephalopod Robot Friend Progress

Cephalopod Robot Friend, the story so far