Champaign-Urbana Community Fab Lab
Champaign-Urbana Community Fab Lab

Locamoting Pom Pom Robots Project – David He

Motivation and Initial Design:

Instead of doing something that mimicked walking, as seemed the case for most others, I decided to work with something more mechanical instead. Now, obviously wheels and propellers were out of the question, since the servo could only rotate 180 degrees at most. Instead, I happened upon the idea of a rowboat, and realized I could obtain a loop-like motion by chaining two servos together (https://www.youtube.com/watch?v=bpvC5AVfEVY for inspiration)

I wanted to use the base of a Grecian/Viking warship, with a large number of oars as propulsion. The ‘oars’ would be made using basic wooden dowels, and for lightness’s consideration I wanted to use cardboard/paper for the body. However, the main issue was the ‘slots’ for the oars to be sturdy enough to withstand the oar’s rotating motion, so I decided to stick with cardboard for the first prototype and hopefully laser-cut a housing for the second one.

The basic sketch/conception of the robot.

Build Process and Modification

There were a few things that came up on the prototype. The first was the fact that the servos had tiny extensions on the side to allow them to be screwed or bolted on external surfaces. This becomes problematic when attempting to lay the servo on its side, so I had to use some extra cardboard to elevate the servo so it stayed flat:

Padding at the bottom of the servo to allow it to lay flat

I also used thin-gauge wire to substitute in as a push rod/extension for the servo arms. The thin gauge allowed it to loop and slot into the servo arms nicely, but when placed under pressure and movement it also began to bend easily.

A good view of the arm extensions and oar mechanism. Note the bending in the extensions (green wire)

I attempted to rectify this by reinforcing the center areas with thicker-gauge steel wire, but its effect was limited. This are is probably the weakest part of the design, with the best alternative to use actual push rods found with servos.

The overall result was a bit lackluster (demo video found here: IMG_5476). The primary issues were that the servos were not properly secured to the cardboard, the extensions bent too much and the overall robot was a tad too heavy for the wooden dowels to move without sufficient leverage. I will likely transition to using paper and glue for the next iteration to help secure the servos more, as well as reduce weight. I may also have to acquire more servos and push rods in order to complete this, so until I find push rods the second iteration may have to be held back a bit.

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Pom Pom Bot

Initial Conception

Last week when we started designing our bots, I just doodled a snowman (Christmas may still be on my mind) and thought that it would be interesting to make something that doesn’t have feet move. The most a snowman could do if they could move would be a waddle, so I tried to replicate that throughout this process. Here’s my initial design:

 

I thought at first that it would give better traction to have the propeller stand on popsicle sticks, but once I tried this the whole thing either collapsed or didn’t move at all. I also thought along with this original design that I could hollow out a pom pom to fit the motor inside of it. Once I got to constructing, this also fell apart since I realized pom poms aren’t that big nor is it possible to hollow one out. 

 

Initial Construction/Prototype

My first prototype was just the base of the bot with one motor that would be the primary movement and a ring of pom poms around the motor. I played around quite a lot here with the code to make it move the way I wanted. If the motor moved too fast or slow to go back to its original position, it would reverse the movement just made so I had to find the perfect delays and angles that the propeller would go to in order for it to move properly. 

 

https://drive.google.com/open?id=1LoO4YJfeYrNpetLo_WwR_FuweoMOJ0oa 

https://drive.google.com/open?id=1BEyZ–wSuuta6knbVUoLYBRcOx_N-NKa

 

As seen above, I just did random colored pom poms for my prototype since there weren’t many white ones and I wanted to save those for my final design. Moving on, I had to decide how I would build the base up with another motor and the pom poms surrounding the entire thing. Pom poms were working pretty well, I just had to be careful about my placement of them so they would not interrupt the movement. 

 

2nd Prototype 

Once I had the primary motor functioning properly, I had to add my second motor. I wanted it on top of the previous one since it would be the least likely to interrupt the movement of the base. I didn’t want to glue the motors together obviously, so I took some putty and sealed the two motors together temporarily. The code for the second motor was easier since it didn’t effect the movement of the entire bot too much, but there was still some playing around that took place in order for it to be correct. It looks a little spastic, but I had to program it a little strange so it wouldn’t hit the pom poms as much as it could have. 

https://drive.google.com/open?id=16TMO5dl5-ZzabVmcvdfGU7yiyB2pAiZW

https://drive.google.com/open?id=1hTjOB2YfbNIyyKAaiEjf_iPE6FDjpDdT


Overall, I was trying to create a snowman image with my additions. The motor ended up being a broom made out of pipe cleaners, and I experimented with adding more pom poms in order for it to appear like it had three tiers, each smaller than the last. 

 

Final Bot

After I had worked out the kinks with the code, my final bot design was focused on the look of it and how it moved with the extra weight on top. I got a bunch of white pom poms and hot glued them together to create the closest image of a snowman I could. I couldn’t glue the entire thing together, or else I thought I would damage the motors, so the top part is just stuck on top with some more putty and a paperclip as support. The bot definitely moved slower that it did without all the other additions, but it can still move from point a to point b – just a little slower than it did before. Overall, the final bot was not too different from my original concept, I just had to adapt to changes and be creative about fixing problems. While programming and crafting as not new to me separately, I had never done them together before which was a really interesting experience and it occurred to me just how much you can do with simple technologies like this. 

 

google drive link: https://drive.google.com/open?id=1IDozK0A9jRfa95ccKO-WBvoDQPOqyyjX 

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Jacob Pruiett Arduino Locomoting Robot Post

For this design, I wanted to make a robot that dragged itself across the floor with an arm. I decided I wanted to give it an alien look, and wanted to give it a look inspired by the face huggers from the aliens movies. I think just using popsicle sticks, glue, and rubber bands will be all I need to construct the robot. Below are the bare-bones of my pompom bot I built in class, and later used in the construction of my first prototype.

Most of my different prototypes were in the different iterations of movement style, as actually getting the robot to move was much harder than I had anticipated. In my initial design I tried to make the robot move with its arm in one big sweeping motion, having the shoulder joint lower first, then having the elbow joint turn 90 degrees rapidly. This caused the bot to fall over a lot, so changes to the weight of my robot and the speeds/angles of the motors would be necessary.

For my next iteration I decided to give the bot a broader body, and to try having it push with the arm at the rear, rather than pull from the front. I also shaped the popsicle stick on the front part of the arm to be somewhat more pointed, to allow for better grip. This ended up being able to move, but not very well, and went to one side for some reason.

For my final design, I really wanted to get the forward dragging motion correct, so I used a body similar to my second design, and tried to apply that to a design with forward movement. I tuned the angles to move between 45 and 135 degrees, and that seemed to work well. 

Here are some pics from the building process, I decided to use a green color and a bunch of eyes to give it a cartoony, but alien look. I also had to keep the profile lower to the ground to get it moving.

  

My initial tests for this design didn’t go great:

So I decided to try added some more friction to the arm with a rubber band:

And it works pretty well! The bot itself has a much larger body than my initial design, and the additional friction at the tip and changes to the angles the arm functioned at really seemed to help. I was surprised with how much difficulty I had with a lot of this design. I had figured it would be a piece of cake, but there were a lot more nuances to it than I had anticipated. In the futures I would want to try running multiple arms to further imitate my original inspiration and give it a creepier look, and maybe try for actual walking rather than dragging as a form of locomotion. 

 

Overall I was pretty satisfied with my final design, and had a lot of fun making it to boot. Many of the issues were in minor details of the build, but just as in the first arduino lab, it was a familiar kind of process, so it wasn’t frustrating to debug these issues. Learning to use the servos was a lot of fun, and will actually be useful for me in other classes as I need to work with servo motors in my senior design class.

An additional note, I took a number of videos, but the website wouldn’t allow me to upload them to the page, so I only had the shortest videos I made available.

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Pom Pom bot but by air.

Description.

For this assignment we are to use arduino and some 9g servo motors to creating a robot of some kind that can move at least an inch. Over the course of the assignment we are to: design a concept, design a prototype, make a 2nd prototype, and make a final bot that moves the inch. For the concept we are to put our ideas out on paper in a sketch or in words. For the prototypes, we are to describe what challenges we face and how we plan to combat these challenges. Same goes for the 2nd prototype except we have to talk about what improvements we made from the first prototype. I went about this project a little bit differently, my robot traveled by air. Air as in it traveled along two balance beams that were held up by two tables (you’ll see in the video). This project was a bit stressful, I’ll speak more about that in the reflection. 

 

Initial Design.

The initial design for was air travel robot was to have a single skewer hold the servo in the air and move each end a couple degrees at a time. Basically my robot was going to look like have of the thing constructed below.

 

My robot would use: pipe cleaners, skewer, pom poms, Popsicle sticks, servo, and a bent paperclip. Pipe cleaners were used to hold everything in place. Skewer was used to hold the servo in the air. Pom poms would act as anchor points, these would ideally move down the balance beams. Popsicle sticks would be used to construct the beams it would balance on. Servo for movement. Finally, the bent paperclip would be weaved through the servo fin to hold the pipe cleaner skewer in place when moving. 

 

Initial prototype.

This video shows my first prototype and the biggest issue that I would spend many hours trying to solve. That issue being the fact that the skewer and servo motor are separate entities. Since these two are independent from each other they will not move in unison. Either the servo moves or the skewer moves. If I were to pinch the servo motor with my hands the robot would travel that inch no problem. So, I started to think how I can unify these two parts. I will not change the base of my design but, I could add a couple things to the servo to hold it all together. I thought of using rubber bands and an extra pipe cleaner to hold everything more tightly together.  

2nd prototype

Here is what the 2nd version looked like. The new pink pipe cleaner is wrapped around the center of the skewer and motor. This pipe cleaner actually did a nice job of holding it all together! Next I would take two rubber band and quadruple bind both side of the skewer. The servo motor has these little notches on the side that made for great rubber band sockets. Overall the 2nd prototype was far more secure that the first one. 

I don’t have footage of the testing but the same thing happened, it didn’t move. The servo was still acting as an independent body. This is where I discovered that force was not my solution so I began to look elsewhere (not force) for my final design. 

I began to think back to my initial design, about why it didn’t work. I said that, if the servo didn’t move the skewer would, thus I should try to find a way to hold the servo still. I tried to work against the separate bodies when I should have been working with them. Once I thought of this, I finished the project in the next 20 min. 

Final Bot.

https://www.dropbox.com/s/90vp1q8sacqmz94/20190408_181624.mp4?dl=0

Side note: I will never get over hearing myself in recordings, yuck.

So, here is the final design! Like is said the problem was not the force but of holding only the servo in place. The way I did this was by putting two large Popsicle sticks right next to the motor. These Popsicle sticks would be held in place by the force of two tables pushing on them. These forcefully held Popsicle sticks would act as walls for the servo to stay in place. In the video, one of the Popsicle sticks fell. This reduced my robots movement speed to a shimmy but still got the job done. Instead of being held still the whole time, it would only stay still for a small about of time, thus the shimmy.In this assignment (I’d imagine) one would have three key components: Means of travel, motor, and a core. For the bulk of this assignment I only had the motor and core. Not until I found my means of travel, did I complete this assignment. These side sticks seem odd, but think of it like they are feet. They are a means to move not directly connect to the main body. Would a robot with just toothpick legs be able to move? That is how I justify this addition. 

Reflection

Once again, I made this projects leagues harder then it really needed to be. Traveling by air proved to be a bigger challenge than I initially thought. Physics and stubbornness were my biggest issues for this project.

The issue of physics was the initial problem that made this assignment harder than it needed to be. To start off, the wacky physics I had to deal with we solely because my robot was in the air. Where most would have a robot that would exude a force back on the table, keeping everything together, my robot exudes a force downward, pulling on the sticks. I do not have the physics expertise to competently explain this, but this pulling down force seems to have made the two bodies separate. Moving on, stubbornness forces me to not give up fast enough to pursue alternative solutions. I usually get so fixated on a route to the point where I end up forcing it to work. This is more of just a personality trait that gets in the way more than a specific assignment issue.  Overall, stubbornness and ignorance do what they do and delay progress. 

As you have noticed my robot only had one motor and not the required two. This was due to be just assuming details instead of actually reading them. I figured we just had to make a robot move, and that the two motor robot was only for class. Since learning this error, I have thought about about a couple designs that I felt I should throw in, for what it’s worth. first design would look something like this -> \_🔲|🔲_/ The boxes are the servo motors and the lines are the Popsicle sticks. This robot would employ a climbing movement along the Popsicle sticks. I would have to put notches on the outer side of the popsicle sticks and something on the ends of the arms so that the arms would have something to hook onto. Almost a sliding lock. The other model would be like the initial two motor design at the top of the post. The design would be a cross that would spin continually on top of two layers of Popsicle sticks. Once one half of the wheel crossed into the middle (where it would fall) the other half would be holding it up. Ideally, in a perfect world, this design would act like a wheel as it spins down the lines of sticks. 

 

 

 

 

 

 

 

 

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Locomotion Pom Bot

This week, I tried to build a machine powered by an arduino and two servos that would walk. My initial design had two servos tightly rubber banded together, with popsicle sticks glued onto the mounts. I did a lot of experimentation with getting it to move differently by changing the rates and timings of turning the sticks. I couldn’t achieve very coordinated motion with this initial design. The main issue I had to consider was how to get the bot to be able to reset the servos after they carried it forward (without the reset moving it backward too much).

I came back to the bot and decided to create a pipe cleaner tripod underneath it and shorten one of the sticks. I thought this might make the movement easier to analyze and increment off of. Unfortunately I had less time than I would have liked to spend with this because I had to go through a lengthy process of elimination of working/faulty parts, which came down to a single malfunctioning wire. I ended up with a robot that moves slowly sideways, and only when set up in a very particular way.

https://drive.google.com/open?id=1pn0TUxjTbDS4RYzyzRfdT4cyWXoqRGjK

I don’t think the video portrays it well, but the bot almost fell off the table while I was tweaking the code and the tripod position.

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Pom Pom Bot Assignment

Initial Pom Pom Design

After considering how different animals move, I initially decided to have my pom pom bot crawl along the ground–with 2 servos with popsicle sticks attached that would act as “arms” that dug into the ground and pulled the bot forward.  The bot would have regular cycles of the arms starting in front of the body, rotating under the body and pulling the body forward, and then the arms quickly rotating the opposite direction to reset the arms back in front of the body and to start the cycle again. Before I started building the circuit or writing code, I drew a quick sketch of how the bot would move (the “Locomotion” section”)  and what the final bot would look like (the “Aesthetics” section).

 

 

Initial Prototype Sketch During Lab Section

A green caterpillar, the image that comes to my mind when I think “caterpillar”

Since the bot would be crawling along the ground, I wanted the appearance of the bot to resemble an animal that crawled along the ground.  Caterpillars and snakes were the first animals that came to mind, but after I saw the pipe cleaners in the lab, that reminded me of the ribbing around caterpillars and that finalized my decision to make my pom pom bot look like a caterpillar; the main body would be a felt cylinder and the ribbing of the body would be made out of pipe-cleaners that ran across the diameter of the felt cylinder to mimic the cylindrical torso of a caterpillar.  The skeleton of the body would be made with popsicle sticks to provide a rigid platform to attach the servos to.  Finally, the eyes would be made with googly eyes or layered cotton balls, whichever one looked sillier 😛

 

Initial Prototype Construction

My initial prototype was a disaster.  Writing the code was easy, but I didn’t realize the servos’ 180 degree rotation restriction would be an issue.  My initial design had both servos resting on top of the popsicle stick skeleton, with one servo motor on the left and right side of the bot, and each servo would sweep under the body at the same time.  However, because the servos could only turn 180 degrees, there was no way to orient the servos such that they rested on top of the skeleton and both rotated under the skeleton.

If you look in the below picture, both servos rest on top of the body (Popsicle sticks).  But because the servos only rotate 180 degrees, the left servo is only able to sweep from in front of the body to under the body (which i want), but the right servo can only sweep from in front of the body to above the body (which is not what I wanted).

The result was that the bot just flailed around instead of making any progress since servos could not sweep the same direction at the same time. See this Google Drive video or this video to see how the 180 degree degree rotation restriction resulted in a flailing bot.

So going forward I had to reconsider how the servos would be placed on the skeleton of the bot.

 

Updated Designs

v2

My next design was a small fix to just place the right servo on the bottom of the skeleton rather than on top–that way the right servo’s 180 degrees of motion would sweep under the body just like the left servo.  As you can see in the below picture, the left servo is above the skeleton (red rubber bands) and the right servo is below the skeleton (left rubber bands), and now both servos could rotate the same direction (in the direction of the blue arrows, under the skeleton)

v3

That small modification for v2 allowed the servos to sweep together under the main body, but after running this design I realized that the popsicle stick arms were not generating enough friction with the table to pull the body forward.  At this point, I had not even added the felt body to the pom pom bot, so the weight that the arms were going to have to pull was only going to get larger and a re-design was required.  After seeing the servos run for a bit, I shifted gears from the popsicle sticks pulling the bot forward as arms, to instead having the popsicle sticks pushing the bot forward as legs since this would require less friction from the servos’ attached popsicle sticks to work effectively.  So the shift from v2 to v3 was adding the felt body and running the servos so that they pushed the bot forward.

However, in v3 the max angle that the servos would sweep to was too extreme and the servos swept too fast (servos swept to a maximum of 140 degrees with minimal delay), so the pom pom bot would erratically jump around rather than moving forward in a consistent manner (as you can see in this Google Drive Video).

v3.5

v3.5 had the same physical construction of v3, but the maximum angle that the servos would sweep to was reduced to 65 degrees in the code.  This stopped the bot from jumping around erratically like v3 did, but now the bot just moved up and down rather than making any forward progress (as you can see in this Google Drive Video)

 

Final Prototype

For the final prototype I made a few mechanical adjustments from v3.5 to make the pom pom bot effectively move forward

  • Changed the maximum sweep angle to 120 degrees so the legs would go underneath the body far enough to be able to push the body forward, but not sweep so far that the bot would jump around when the legs were retracted
  • Added a small 250ms delay between cycles to allow the bot to settle down before rotating the legs again
  • Added a popsicle stick “tongue” to the front of the the body.  Before, the front of the felt body was the only other point of contact between the pom pom bot and the ground when the legs were fully rotated.  But the friction between the felt and the table was too high so the bot had trouble moving forward.  The addition of the popsicle stick tongue lowered the friction between the front of the pom pom bot and the ground (since popsicle sticks have lower friction than felt), so the legs had an easier time pushing the bot forward

This allowed the bot to move forward in a consistent manner.  See this Google Drive Video to see the final bot in action.

And now that the pom pom bot was moving correctly, I added the rest of the aesthetic materials to the bot (pipe cleaners for ribbing and tail, and cotton balls for eyes and nose) to make it look like a caterpillar.  Here are some pictures of the final bot.

 

Reflections on Final Prototype

My final prototype was similar in spirit to my initial design, but physical restrictions (servos only able to rotate 180 degrees, friction with the table) required me to update the mechanics design.  The main change was having the servos push the bot forward rather than pull the bot forward, while the aesthetics of the bot remained the same.

I was surprised how much I enjoyed making the face of the bot.  Maybe it was the relief of not dealing with the servos anymore, but I had some solid giggles when putting on the eyes and the nose of the bot…perhaps the elongated tongue and slightly off-kilter eyeballs gave the bot a derpy charm.

Most importantly, I named my pom pom bot Harrington.

 

 

 

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Arduino 2

For this project I initially wanted to make a robot that does the Woah, a new dance move that’s been all over Twitter these past few weeks. I drew out the arm motions and quickly realized that I’d actually need at least 2 servos going 360* and another servo to move both arms side to side, and so it wasn’t going to happen.

My second thought was to make an old lady with a walker. The idea came from using something similar to skis to grip the floor and bring the object forward. 

The robot was going to be constructed from two servos, which I later placed together at the top of the walker rather than the bottom legs, popsicle sticks for the walker, pom pom tennis balls on the bottom of the sticks for added height and stability, and a little lady made of light weight materials like pipecleaners. 

As previously mentioned, I decided to connect the servos together so that they would be at equal height on the legs instead of trying to measure them later. This would also be more stable on the front of the walker, keeping the robot from falling down. I added popsicle sticks to the servo propellers to act as the front legs of the walker. 

It was at this point that I realized it wouldn’t walk like a walker, but instead the walker would walk and the old lady would follow behind. I decided that this walker would now be intended to drag the person behind while they wear slippers, kind of like when a rollerskater grips on to a moving car.

I added a second leg, then connected 2 short popsicle sticks perpendicularly, and another 2 for the second set of legs. 

IMG_1793

This immediately fell over. So I connected the back legs, hoping that would make the robot more stable, but that fell over too. But here is my prototype. The legs move 45* and one after another, the servos are the front legs to move the walker and also support it upright, and the back end is static. 

This time when I redrew my design, I was a little more detailed about the construction.

I changed the code so the servos would move simultaneously, and to different positions with a shorter delay. I added a third set of legs, so that the walker would be box shaped and that the servo legs would left and drag the walker forward, pulling the woman behind it. I made the servos faster because I thought that would be helpful given the additional weight of the old lady. And I added in the necessary slippers.

IMG_1808

Here’s the robot dragging itself along, and the successful code.

and my final pom pom bot!

IMG_1812

It’s a lot more stable, which was my main goal after the first prototype! It doesn’t fall over, and is successfully able to wobble itself from point A to point B, although not necessarily in the straightest line (I think that has to do with the wires connecting it to the arduino. 

I think the design process was pretty typical. I haven’t felt the need to draw a second design in the past, but since I did this over the course of two days it didn’t feel unusual to start the second day with a different design. I think if it had been different materials I might have completely scrapped the first design without thinking. But I’m not sure how much servos cost, and really the servos were going to be the same in the second one anyway so I’m glad I was able to just add onto the first prototype and fix it’s shortcomings.

 

In case the videos aren’t showing up, here’s the final product:

https://drive.google.com/file/d/1MPIllrtDecOEFC3xaA6Oh6T3FRdgZZMU/view?usp=sharing

 

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Pom Bots!

Initial Idea: My initial idea was to make a caterpillar like bot that moves by rapidly shaking back and forth. The design can be seen below.

In terms of materials I wanted to use pipe cleaners for the bottom so it could grip onto the table and move. Then I would use paper, popsicle sticks and balls of fluff to make the remainder of the body. 

Prototype: Before I started creating the the entire design I wanted to make a smaller prototype to test if the movement I want actually worked.

 IMG_0368

As can be seen in the video the bot did in fact move, technically. It was able to shimmy across the table ever so slightly. Even though my concept would technically work, I decided to try a completely different approach to the pom bot entirely since I wanted the bot to move in a more fluid way. I also found that in terms of code this prototype would only move if the motor was programed to run at a fast speed, with this in mind I also wanted to make the next prototype able to move with a lower motor speed.

2nd Prototype: Instead of making the bot more box shaped like my initial design, I made it lanky and upright so I could attach the motor right side up instead of outside down like the first prototype. Also unlike the first prototype I also worked to make the bot more aesthetically pleasing by making it colorful. This new design can be seen below.

To my surprise this bot worked much better than my first prototype and was able to move at a variety of motor speeds. The only issues I ended up running into with this prototype was legs becoming separated from the motor, to help mitigate this I wrapped a pipe cleaner around the servo motor itself to keep the legs close to the motor even if they fell off of the propeller. The bot in action can be seen below.

Untitled

Comparing this version to the first prototype, it is easy to see that the movement is much smoother. With this in mind I felt that overall this design was pretty close to where I wanted the final product, the only improvements I wanted to explore was making the legs more stable and find a way to get the feet to not cross over each other as much.

Final Pom Bot:

I unfortunately did not have the time to completely finish the idea of my final pom bot. However, I do have an image of how I would have gone about stabilizing the feet.

While I didn’t get to test this with the motor, I feel like having one or two piper cleaners attached to the feet would help make the bot shake less violently, which would also help in keeping the bot together.

In terms of the locomotion the first  bot just kinda spun in place and slightly shimmied forward, whereas the final bot actually moved forward with a very janky form of walking. 

I was surprised how I made a pretty specific drawn concept, however once I actually got the hardware and started working on it I quickly threw out my initial idea and designed something very different. With this in mind for future projects, I should create more than just one initial idea so I have more to work off of if one of the ideas doesn’t pan out. 

 

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Locomoting Pom Pom Bot Assignment

For this week’s assignment, we worked with Arduino to create locomotive pom pom robots.

In lab, we explored servo motors and played around with the servo example sweep code. We added a second servo and tinkered the code to gain a better understanding of the operations. We had a few minutes to change the delay, angles, and positions.

After, I sketched a rough concept of my locomotive pom pom bot. My idea was inspired by the way penguins move; they waddle. To mimic the movement, I played around with angles and started off with two sweeping 90 degree angles to act as the feet.

IMG_2088

IMG_2110

Initially, I thought I would make my pom pom robot out of a bunch of pom poms but ended up using foam because I needed a more stable overall structure. Instead of cutting and crafting the parts of a penguin, I decided to origami fold one. I had to super clue the folds down because I was using a thicker material. Then I fashioned platforms to which I would connect the penguin to the servo motors using popsicle sticks. And taped around the servo motors to the popsicle sticks to be positioned on the ground surface.

The initial construction of the pom pom bot had difficulty moving because the way base structure of the foam restricted flexibility in movement. Therefore, I had to do a bit of tinkering of the prototype. I cut the tail of the penguin down the middle to allow for better mobility. Therefore, the servo motors could begin to movie from A to B at 90 degree angles.

IMG_2114

After, I just had to adjust the positioning of the servo motors because they were at an angle of each other, rather than parallel. As well, I had to tinker the code in order to get the servo motors to move in the same direction if I had flipped the motor in order for the servos to be positioned with the rotating bit on the outside of the bot. This was the final code:

Servo myservo; 

Servo myservo2;

int pos = 0;    // variable to store the servo position

void setup() {

  myservo.attach(9);  // attaches the servo on pin 9 to the servo object

  myservo2.attach(11);

}

void loop() {

  for (pos = 0; pos <= 90; pos += 5) {    

    myservo.write(pos);           

    delay(15);                   

  }

  for (pos = 90; pos >= 0; pos -= 5) {

    myservo.write(pos);         

    delay(15);                 

  }

  //second servo

    for (pos = 90; pos >= 0; pos -= 5) { 

    myservo2.write(pos); 

    delay(15);                 

  }

  for (pos = 0; pos <= 90; pos += 5) { 

    myservo2.write(pos);         

    delay(15);                 

  }

  }

I tested the bot once more and found that it waddled exactly how I wanted, which I was really content with. I added a few decorative features, and I would actually say that even though it wasn’t a drastic change, it seemed to slow the bot down a bit. But it still moves from A to B. If I had to redo the assignment, I think I would elongate the connections of the rotating bits of the servo motor  in order to get the penguin possibly to move in longer strides and to essentially mimic the feet of penguins, and then probably design it in some way so that it looks like so.

IMG_2115

IMG_2116

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Arduino: Locomoting bots

Subtitle: shaoyie is not responsible enough to use a hot glue gun.

 

Finished product! Dragon!  (Video will be attached below)

 

I will readily admit I probably should have focused on the “locomoting” part of it a bit more. Got a little too excited about the dragon part, so it uh, it moves. Just… not effectively. Or in the expected direction.

Photo of completed + video:

https://drive.google.com/file/d/1jRvHn8NHHV5jsZw27p9LbVAPHLAmTVdm/view?usp=sharing

I promise it is actually moving. Just….. very incrementally. 

  I uhh… did not actually take that many pictures. /Technically/ this is my first iteration- 

Which is, clearly, having some stability issues. It did actually move a little, but was basically falling over every time it took a step.

https://drive.google.com/file/d/1Bz9OpVuoGCXtxtkIsnHlinu9w2ND1OSr/view?usp=sharing

Which was funny. But also not great.  So I decided to ease up on making it stand on its own, and gave it a little structure frame thing to hold it up properly. 

(This was also when I realized why I don’t normally use hot glue guns. I know the glue is hot. Its a hot glue gun. But I always, without fail, want to poke it.)

In addition, I modified the code a bit to make the steps smaller, so it wouldn’t be flailing its limbs everywhere. The pace of the steps seemed to be generally in line with how walking could actually work, so once I had the general setup down, I kept that. This was actually done by incrementing the degrees of the two legs in one single for loop, which kind of made it so that one leg… lags? might be the best way of phrasing it? behind the other.

 

The final product still wasn’t as good as I wanted. The legs would actually be moving it properly, I think, if I had some extra time to work on it. The issue had to do with the grip the “feet” had + the way they were alternating; they were basically gripping the floor enough to move a little, but the other food was moving with the right timing to then shift it back. I wanted to modify the frame a bit so it would tilt forward more, so that there is grip when the foot moves back, but not when it swings forward. I ran out of time in the fab lab though, so its still not in primo condition. Maybe I will do some extra fixes before class starts tomorrow? We shall see. 

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PomBot – Renuka Nannapaneni

In lab section this week we learned how to control the servo motor with the Arduino board. 

My idea was to get something moving and then create the creature around the movement. I wanted to have something along the lines of wheels so I created this. Originally, I had the connections to the motor in the 

middle of the spokes but the creature would only move back and forth, and then when I off-centered the connection and started the legs in different positions (one with long side down, and other with short side down) the bot moved forward. 

The code, was moving both “wheels” at the same time, but when most variations of the code kept moving the bot back and forth rather than overall forward, I switched it up so the wheels were moving at different speeds. 

This link: https://drive.google.com/file/d/1k-UyeoaqIPv_pwejwWRFfIb5XnK9L9pe/view?usp=sharing 

has the final movement captured. If I were to do the project over I would’ve tried to make the motion more deliberate rather than just doing it by trial and error, and I would’ve embellished my creature more, as of now he is a single eyes spider mutant with stripes on his legs. 

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