Middle School Robotics Presentation

The HipMonster.com’s team was invited to do a middle school robotics presentation last month to show kids the fun side of robotics and technology. The audience was so awesome and engaged making it a fun experience for everyone.

Steam punk slide on robots

The theme was how to take over the world using robots, making it fun to keep the students engaged. We used a steampunk template for our slides to match our robot designs and channeled Girl Genius when presenting.

Steam punk robots in a presentation at school
Testing the controllers

The robots got banged up a bit in transport but nothing completely broke. The biggest issue was the wires getting pulled out from the Arduinos. Luckily, it was only the breadboard jumper wires which are easy to put back in place. None of the soldered wires were broken which could have been very hard to fix. Breadboard jumpers are designed to be repeatedly taken on and off. They are like tiny USB cables and colored which helps see how what each cable is connected to (this is important because sometimes you can have dozens of wires). When you solder a wire to a controller      it can only be broken to be removed. You solder wires by using melted metal called solder and a really hot device to melt the metal. When a solder connection breaks you need to melt the metal again to reattach.

Two steam punk robots with two kids
Fixing the wiring

Here we are putting the finishing touches on Number Two and Number Three. All the robots traveled well and were up in running in thirty minutes except for one whose battery was faulty. When transporting batteries, we take extra care not to damage them and use a special carrying case.

We wrote a quick intro for the robots to perform to set the mood. After the intro, we dove right into robotics.

Three steam punk robots

Here are three robot bodies. The first is Number Three. She can move his arms and hands, and talk. The middle is called Number Five. He can walk forward on his own using his four legs. The last is Number Two. He can’t do much, but he can still talk and move part of his arms.

Four steam punk robots at a school
All the robots lined up in the gym

For each robot body, you need to do several things. There needs to be a skeleton, a power source, and something that makes the robot move. When we are thinking of designs for our robots we often think of animals that already exist. We also take inspiration from robots in different books and webcomics.

Robots at a school presentation
Presenting to the school

Number Four is the most complicated one. It took us over one year to build her, and she is still being modified. Many other robots were also not built all at once but were gradually assembled as we got new ideas.

Arduino and a robot

After you build the body, you have to give the robot a brain. in our robots, we use something called an Arduino.

It is basically a tiny computer that you can program to do different things. For our robots, we use Arduino to make the robot walk on its own, so we don’t have to use a remote control. For one robot, the Arduino can also choose the direction that it walks in, and how fast it walks. You can find a simple example here.

We code the Arduino from our computer, then the Arduino sends messages to the robot to control it. We edit the code based on our observations and new ideas.

Steampunk cat robot

We have many different types of robots that can move their whole body, each type demonstrates a different way of moving. We have the 4-legged walkers, which are our first moving robot design. They are made of metal pipes and have four legs and wheels for feet. We put wheels on their feet because we wanted less resistance and friction, but we didn’t want the robots to just be like a remote-controlled car. We wanted them to walk. The design of the legs and the “knee” has made a big difference.

Robot seal

Another design is our Seal robot. This one is very different, as it only has two legs and no wheels. The legs pull themselves forward, powered by linear actuators. To make sure that the legs don’t just go backwards and stay in place, we put wedge-shaped bits of foam at the bottom of the seal’s legs. When the seal moves forward, the wedges give no resistance, but when the legs pull back, the wedges stop them.

Steam punk Robot Bunny

The next robot is our Bunny robot. The bunny robot is also unique because it was originally designed to hop. The two back legs push it forward, thanks to the springs. This one is powered by air and pistons, so you can get the sudden jolt that is harder to achieve with linear actuators. This robot is also one of the only robots made mostly out of wood. We took the idea for the legs from our wooden toys.

steampunk kangaroo robot

This is the Kangaroo. The kangaroo’s main difference besides the number of legs is the feet. The feet are small animal toys, designed to only go in one direction so they can move forward more efficiently. The back leg powers the whole robot, and we used linear actuators.

Steampunk mouse robot

The last robot is the Mouse. The mouse is just a broken blow-dryer attached to wheels from some old toys. It is very simple, so we decided to make it walk on its own, completely uncontrolled and completely randomly, controlled by the Arduino. You can see the code here.

The mouse in action

Sorry, this photo was blurry, but the mouse was super fast that day-well charged batteries.

We want to give a big thanks to all who came to our presentation, and everyone who helped and supported us! this was our first big presentation, and we couldn’t be more happy with how it turned out!

Happy creating!

Number Three’s Controller

Please note, this material is provided for informational purposes only and is not a guide on how to create the designs. Please take a look at our disclaimer.

This post is an old one we forgot to publish a while back. Currently, Number Three is controlled by a script that is run on a Raspberry Pi sending commands to an Arduino. But originally Number Three was controlled by a wireless relay switch. We used wireless relays at first because they are simpler and we could just focus on the mechanics of the robots. As our robots got more complex, we had to migrate to Raspberry Pis. This post is a good overview of wiring a relay and even if outdated gives good insights. Also, a wireless relay may be useful in other situations.

wiring for a robot control unit

Here is a 12-volt, 16 relay wireless board. It is typically used for lighting but we have other purposes in mind- robots! To begin here are some basics. To control motor you change the power going it. A motor needs positive (red wires) and negative (black wires) energy to work. A relay controls power going to an engine. When wiring a relay the wire that gives the signal (what tells the relay to be on or off) is usually a color other than red or black. In this case the color is light blue.

wiring for a robot control unit

Honestly there is not too many parts to this build just the relay, linear actuators, wire nuts and a lot of wires. We recommend doing the build in an area easy to clean and free from pets. When you cut the wires little bits of wires can fall to the floor may end up in the foot o a pet.

wiring for a robot control unit

The wiring for the relays proved to be more difficult than we thought because the wires were slightly thinker than the connection wanted.  We had to twisted them tightly to fit them in. If you are buying wire go with a thin grade.

wiring for a robot control unit

When doing a wiring job of this scale, over 64 wires, it is best have a plan laid out before starting and if possible divide the labor. Our plan was to wire in order or wire type (signal, positive, negative, output).  To make it easy we cut all the wires the same length. To attach the wires we used wire nuts but have migrate to using lever connection nuts for quick builds.  The wire nuts proved to be too finicky and we don’t recommend them until the final build.

wiring for a robot control unit

Here is a pile of pre-linked positive wires. Since we wanted to control a linear actuator we need to use two relays to control on the power. To make an actuator extend and retract you need to you flip positive to negative,  this is called reversing polarity. But one relay can on turn power on and off. So to be able to reverse polarity we needed to wire XOR logic gate. This is a good overview of how to control linear actuators and here is a good diagram on a XOR XOR logic gate.

wiring for a robot control unit

Here is the completed relay ready for testing.  Make sure all the wires are screwed in tightly and no fray wires are touching before pugging in the relay.

And what better way to test than knock something over and make a big mess!

wiring for a robot control unit

Here is the new controller installed on the back of Number Three. Since we are aiming for a steam punk robot the mass of wires is exactly the look we wanted.

Happy Creating!

Cosplay Tail

Please note, this material is provided for informational purposes only and is not a guide on how to create the designs. Please read our disclaimer.

One thing we have always been jealous of is tails. Cats and dogs flaunt them as they strut around waving them in the air. So when making our dragon costume, we wanted a moving tail that seemed alive. Not a dead tail but one that had a personality of its own.

We searched through our past builds and thought the joint work on our little wooden robots would do the job. We also so some cool designs on the web like this one.

Parts needed to build a cosplay, wooden, flexible tail.

This build just needed some wood, bolts, wood glue, rubber bands and lots of duct tape.

sistering two wooden dowels

Since we wanted the tail segments to interlocked we glued two pieces of 2 X2 wooden dowels together. Be careful not to put too much wooden glue- it just needs a thin coat. Give it two days to dry; you don’t want it to come apart when you start cutting.

measuring wooded dowels

Measure out the segments carefully. You can vary the lengths depending one what look you are going for. We went with four inches length on the top part and one inch slots on the backside.

Here is a view of the final design. Each segment will have the same “hat” shape.

a cosplay, wooden, flexible tail.

Each hat will fit together in an alternation pattern. We tried making the segment in “z-shape” but it did not move as organically as the “hat-shape”.


Drill press

After carefully measuring, we used our trusty drill press to make the holes. Try to make a tight fit for the bolts. If the holes are too big the tail may stick over time as the bolt cuts into the wood.

Making a cosplay, wooden, flexible tail.

Now it is time to assemble! It fits together like puzzle pieces. Make sure to put bees wax on the segments to protect the wood.

Create a base for a tail

Now on to the belt for the tail. To create a base for the tail we used cardboard and high grade duct tape.  An earlier build with standard duct tape did not last very long.  First cut out a piece of cardboard about 5 by 8 to help guide you as you “weave” the duct tape.  The cardboard does not provide any real support but just helps you remember the shape.  The bigger the base, the more stable the tail will be.

creating a base for a tail

Weave strips of duct tape alternating between vertical and horizontal directions. You want to use several layer, enough that it can support the tail.

creating a base for a tail

Next careful cut four slits in the base for the belts. We recommend two belts but one top belt can work depending on your custom. We used camping stapes for the belts with fast release clips to making taking the tail on and off easy.  Here is another design that we borrowed element from.

detail of a cosplay, wooden, flexible tail.

Next punch two holes in the base for the bolts to secure the L-braces. The L-braces will attach the tail to the belt. Use big washers when attaching the L-braces to prevent them from twisting into the duct-tape.

A cosplay, wooden, flexible tail being assembled.

Now, attached the tail using four wood screws. Use small screw and drill guide holes; you do not want to split the wood.

Top view of a cosplay, wooden, flexible tail.

Finally, add two rubber bands at the base to give it some life and your tail is ready to be flaunted!

Back of a cosplay, wooden, flexible tail.

Here is a back view showing how the base looks when completed.


Two cosplay, wooden, flexible tails side by side.

Here are both tails completed!

Happy Creating!

Carved Wooden Seals

Please note, that this material is provided for informational purposes only and is not a guide on how to create the designs. Please read our disclaimer.

As presents for our teachers last year, we decided to make a series of stamps. we chose cats because we like cats  We prefer using a Japanese saw because it gives us a clean cut and is much easier to use.

Making Wooden Seals

To get the basic cat shape we do rough cuts with the saw, then use a craving tool to  clean up the edges.  The make sure the vice does not cut into the wood we used scrape from an old pair of jeans.

Making Wooden Seals

To get the ears we need to create a negative space between the slanted edges we just cut. The do this we first cut several slots making sure to stop just short of the end of the slanted edge. You do not want got beyond that point or the ears will more like bunny ears than cat ears.

Making Wooden Seals

You want to have several slots cut to to make removing them easy. If the slots are too thick when you try to pop them out (the next step you could instead break off the ears.

Making Wooden Seals

Once we have cut the slots we use a chisel to pop them off. Make sure to go slow and start with the center slot. When you pop off the ones next to the ears make sure to have the flat edge of the chisel pointed towards the ear. Most of the time this works like a charm but sometimes the wood refuse to cooperate. If this happens to you try you best then try using other tools like a flat head screw driver. Worst case use the chisel to cut the out and if nothing works just start over.

Making Wooden Seals

Then we used the chisel to clean up the rough parts between the ears. Two of the seals in this batch had slots that broke off half way making the clean up job a bit hard. Go slot and do not use force. If the chisel is sticking it is either at the wrong angle or you are trying to carve out too much in one go.

Making Wooden Seals

We use a rasp to finish it out.  You can use sand paper as well but we like how you can shape thing with a rasp.

Making Wooden Seals

Next we used a spoke shave to round the edges of the square dowel to make it more cat-like. Again, do not force the tool. Just use a gentile motion while applied light pressure. If you use too much force you can cut into the wood.

Making Wooden Seals

Then sand to get the finished look. And remember to take the time to sand it right.  After all the work it took to get here you do not want to spoil it by not having a clean surface for painting.

Making Wooden Seals

For a finishing touch we made a cut all the way around the seal to create a neck for the cat, We made sure the cut was not too deep and went evenly al the way around the body.

Making Wooden Seals

We then used a craving tool to widened the cur being careful not to cut too much out.

Making Wooden Seals

Here is a line up of all six seals ready for painting!

Making Wooden Seals

For each seal we picked three different colors to create a unique theme.  We used acrylic paint for these seals but you can us wood stain or oil paint if you prefer.

Making Wooden Seals

This one reminded us of lava!Making Wooden Seals

We painted the layers over time to make sure each color stood out and did not blend in with the rest too much.

Making Wooden Seals

All six seals with their paint jobs finished!

Making Wooden Seals

The seal for the seals was made of an eraser.  We used wood carving tools to engrave them. Make sure you do a reverse image of what you want printed!

Making Wooden Seals

Here are the seals with their seals.Making Wooden Seals

We attached the eraser to the seal using hot glue. Make sure to score the bottom of the wood seal and the eraser so you get a strong bound.


Happy Creating!

Wood Carvings: Pony

Please note, that this material is provided for informational purposes only and is not a guide on how to create the designs. Please read our disclaimer.

This quick creation was inspired by Pinkie Pie from My Little Pony. We love Pinkie Pie’s bright outlook and humor!  When we found a scrape of bright colored faux fur in our recycled fabric box we all thought of her right away.

Carved toy pony
This is a side view

We used balsa wood for the body and faux fur for the mane. It took a while to carve since ponies have a specific body shape. We first drew the basic outline on the balsa wood then cut out the rough shape with a saw. To make sure we did not damage the wood we wrapped it in leather when it was in the vice. Then we used wood carving tools and sand paper to finish the shape. The head was the hardest part to get right. Ponies have a very specific look to them. We used a wood carving tool with a groove to get the fur just right.

Carved toy pony

The mane was stapled on to the body then pulled over to cover up the staples. To give it a bright color we used a red wood dye. The dye also showed off the pony’s carved fur.

Wooden little pony

After a quick comb our little pony was ready to roam the world!

Happy creating!

Foam-Mo Fun

This is an introduction to one of our favorite making materials, Foam-Mo. Foam-Mo is really great for making models of organic stuff, such as plants and animals, whereas regular air-dry clay has the wrong texture. The Hand of Glory, from one of our other posts, was also made out of Foam-Mo.

This is an introduction to one of our favorite making materials, Foam-Mo. Foam-Mo is really great for making models of organic stuff, such as plants and animals, whereas regular air-dry clay has the wrong texture. The Hand of Glory, from one of our other posts, was also made out of Foam-Mo.

Please note, this material is provided for informational purposes only and is not a guide on how to create the designs. Please take a look at our disclaimer.


This is what Foam-Mo looks like when it’s packaged. If you want to work with Foam-Mo, you should also get some plastic spray, because without the plastic spray Foam-Mo can disintegrate over time.

Foam-Mo creationFoam-Mo creation

Here are some of the small designs that we made. Like we said earlier, Foam-Mo works well with organic stuff. Foam-Mo is really soft, and moldable, and not sticky at all. You should not need to add water, because water can damage the Foam-Mo. While working with Foam-Mo, we used some of the same techniques that you would use for regular clay to mold it.
Foam-Mo creation

Here are some more animals that we did, two small snakes. Foam-mo can be rolled really thin, but it holds the same risk as air-dry clay when it it thin. As it is very soft, it also might need supports while it is drying. For this project, we had to prop up the heads to prevent drooping.

Foam-Mo creation

This is what it looks like after is is sprayed with plastic. Make sure to do multiple layers, and get every part of the clay. Make sure to spray it AFTER the clay has finished drying.

Foam-Mo creation

Here is a cat that we sprayed and painted next to one that we didn’t. The cat that didn’t get sprayed looks droopy, and has the wrong texture, due to the fact that we left it unsprayed for over a year, and it started disintegrating.

Foam-Mo creation Foam-Mo creation

Here are two projects that we finished spraying and painting. The colors show up pretty bright, even though the plastic spray was black. We did multiple layers for some of them, but I think that the paint worked pretty well. We used acrylic paint, but you can research and find your own paint.

Happy creating!

DIY Moss Terrarium

Please note, this material is provided for informational purposes only and is not a guide on how to create the designs. Please read our disclaimer.

What do you do if you break a pot? This fun DIY moss terrarium will teach you a great way to decorate your space with recyclable materials! It will brighten up your space and help you avoid throwing away useful pottery!

moss terrarium

Let’s make a moss terrarium! The first step is to pack in as much mud as you can without the mud falling off. You can press in flat shaped rocks for stairs and platforms, then put more mud on top of it for more support. To create stairs, find similar sized rocks and stack them on top of each other, with space in front of it.

moss terrarium

Here is what it first looks like after you attach the platforms. We used slate as our rock, because it is very flat. We also put some rocks along the side of the pot to look like the side of a cliff.

moss terrarium

Use a paintbrush and water to clean mud off of the rocks and the front edge of the pot so it doesn’t look too dirty.

moss terrarium

Next, before the mud dries, walk around outside to gather mosses and small plants. Gently tear the moss to the right size and press it into the mud. More is more, so put moss on every available surface to make it look more like a forest. If the soil is too dry, or not sticking, slowly add water in small amounts.

moss terrarium

For the small plants, poke a small hole and press it in. Put more moss over the exposed soil around it and press. If it is too small, first make a ball of mud around the roots of the plant and then press it in.

moss terrarium

Gently water all of the plants with a mister or with your finger. Do not dump too much water all at once or you will kill your small plants and/or sweep away the rocks and mud.

moss terrarium

You can also add some small decorations on the terrarium to create a landscape or a scene. Make sure to water it regularly! But if your plants die, you can use the same method to replace them!

Happy creating!




SF Zoo Fundraiser Jewelry

To support the San Francisco Zoo, the HipMonsters’ sisters team, and a neighborhood friend decided to sell jewelry to raise money and awareness. Their efforts were a great success, raising nearly 400 dollars in two days of work, thanks to the generous and kind people of San Francisco.

Here is a selection of just some of the jewelry sold! The jewelry is made with molding clay and painted with acrylic paint.

Thanks again to our neighbor friend and all the kind people who donated!

Making of Number Six and Number Seven

After finishing Number three, we wanted to make smaller and lighter walking robots. Leveraging what we had learned from building our first walking robot, we made two mini robots, Number Six and Number Seven!

Please note, this material is provided for informational purposes only and is not a guide on how to create the designs.  Please read our disclaimer.

Because we had a completed robot design it was easy to make sure we had all the parts we needed before beginning. Since Number Six and Number Seven were smaller we were able to spend about the same amount of money but use lighter steal parts. We hoped the reduced weight would make for better walking performance.

making a robot

The steal tubes also had bolt threads as apposed to pipe threads. Pipe threads are “V” shaped which made it difficult to get a piece tightened pointing the correct direction. With bolt threads we could use a nuts to tighten the connection between the tube and the pivot joints however they were positioned.

Working as a team the assembling went fast and in less than a day we had the beginnings of two robot. One trick we have learned is to use the floor as an assembling space. We are cramped for space and using step stools can be tricky in a workshop so the floor tends to be safer.

Here is a completed frame. It cannot stand yet and has to be held up. Here we had the initial knee designs. The knee design was important when we were developing the first walker. Later we switched to a tube in the piston rod that acted more like a spring to prevent the leg from over extending. What is critical in our approached is letting the robot fall forward but stop the fall before the robot is in a position it cannot recover from. The sister team learned this trick from a class at school where the teacher said when humans walk forward it is more like a controlled fall.

Now we start on installing the air pistons. We had to repeat this process many time because we kept switching around to position of the pistons and the direction of the air tube couplings. If the pistons are not the same on both side the robot will veer to one side and if the coupling are facing apposing ways the tubing becomes impossible to arrange.  We have found facing the coupling up is typically the best orientation.

We did have to modify the piston attachment by removing the peg. This did require a parent’s help as the clip that secured the peg was difficult to remove without breaking it.

making a robot

Next we began attaching the pneumatic air tubes. When measuring make sure to know were the pneumatic solenoid valve will be attached and account for the full movement of the legs. It is best to do one tube, test it, then do the opposites side. We found as we added tubes we had to change the initial lay of of the tubes. The tube work is a bit of an art form much like wiring a control unit.

Here is a close up of the all the piston installed.


making a robot

Here is another view of the tubing being fitted and a close up of the pneumatic solenoid valve. Make sure to do clean, straight cuts with a sharp scissors to assure not leakage when attaching to the couplings.

making a robot

Here is a front view of a completed design for Number Six and Number Seven. For testing we used a leather book strap so we could reposition the components as needed. We also tested a number of different air pumps. This pump, which we did not use in the final design, was the quietest and used the least amount of power.  Latter, we switched to another model because this model kept shutting off after prolonged use.

DIY Robot

Like with other designed we used a garage door remote controller because it reverse polarity to the pneumatic solenoid valve which switches the air flow from one leg to the other enabling the robot to walk. It is the small black box in the center of the robot.

DIY Robot

The battery we secure to the underside for protection (the light blue box under Number Six). Instead of doing lead acid battery for Number Six and Number seven, we switched to a 12V 6Ah Lithium Iron Phosphate Battery from our lead-acid battery due to it much lighter weight and increased amps.

DIY Steampunk walking robot Number 6Here is Number Six walking in our yard.

DIY Steampunk walking robot Number 7

Here is Number Seven walking in our workshop.

Steampunk DIY walking robots

And here we have all three robots, Number Five, Number Six, and Number Seven going for a walk together! The larger robot is Number Three. Number Seven is in front and Number Six is on the left.

Happy creating!