Cosplay Tail

March 30, 2024March 30, 2024 Lutin

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.

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.

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”.

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.

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.

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.

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

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.

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!

Making of Number Six and Number Seven

October 7, 2023November 15, 2023 Lutin

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.

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.

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.

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.

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.

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.

Here is Number Six walking in our yard.

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!

Making Mandrake Roots

September 10, 2023October 7, 2023 Lutin

Inspired by the character Professor Sprout (from Harry Potter) and this wonderful article, we set out to make our mandrake root for Halloween.

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.

Mandrake roots are a mythical plant that has a root that looks like a person. They scream when they get pulled out of the ground, and hearing the screams can knock you out, or even kill you. They are featured in Harry Potter, but were invented before that. For more information, go to the article above.

For our mandrake roots, we used a type of foam-like clay called Foam-Mo. Foam-mo is really useful for making organic details like plants and animals. It air-drys and can be painted, but has to be sprayed with a plastic spray, or else it will disintegrate. We recommend using several layers of the under-coat spray for maximum protection. We painted the mandrakes with acrylic paint.

DIY mandrake root

Make sure to use a nonporous surface for a build table or the Foam-Mo will stick to it once it dries. We used old cutting boards.

To make the mandrakes, we made ovals for the head and body, and tubes for the legs. We also rolled out thinner tubes for the tree branches and flattened small diamond shapes for the leaves. We used a pencil to made the lines in the leaves and to make the eyes, lines on the body, and the mouth. Remember, no two mandrakes are the same, so make them all slightly different.

Foam-mo is pretty delicate, so we needed to be careful when attaching stuff. To make it hold it’s shape, we used stuff to prop up the mandrake roots while they were drying. to make the edged look like roots, we gently pulled out thin strands of Foam-Mo at the end of all of the limbs.

After the Foam-Mo dries, we sprayed it with a plastic spray and painted it with acrylic paint. We painted them all slightly different shades of brown and green.

Please DO NOT water your mandrake, even if they tell you to! They are definitely not waterproof.

Happy creating!

Upgrades to Number 3

July 15, 2023October 7, 2023 Lutin

Since we discovered how to make Number 5 move, we decided to upgrade Number 3. We tried to preserve as much of the original design as possible, so we didn’t mess with the decorations or redesign the frame. We also made the legs stronger so the robot could support itself easily and won’t fall. Professor Brockenhoff was very pleased with being able to more effectively scare strangers!

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

We started off by disassembling number three. Given how Number Three was designed as a framework, it was pretty easy to take apart.

Number 3’s Arm being Upgraded

We wanted to upgrade Number 3 to make it move. Since walking with two legs is incredibly hard, we decided to only make the arms and hands move. We first used hinges to upgrade the hands so that they could open and close. Next, we had to replace the fixed joints with movable joints. Borrowing from extra part from Number Five, we added flexible joints for pipes to power a air brush. The added weight of the metal join required use adding more support for the legs. We tried plastic joints, but they failed durning testing.

Then we attached lightweight linear actuators to the joints to move them. Given we wanted more controlled movement and a quieter robot for our front parlor, we opted for electronic verse pneumatic power. We attached the linear actuators so that when they extended, the arms reached out and when they pull back, the arms bent.

And finally, for controls, we used a remote control unit for garage doors. Since we need the polarity to switch (the wires reverse, positive/negative to negative/positive) to have the linear actuators go in and out we had to make sure the control unit reversed the polarity not just turned the power off and on.

And now you see the update Number Three testing its arms with Professor Brockenhoff at the controls!

Happy Creating!

Color Splash Collection, Summer 2023

July 15, 2023July 15, 2023 Lutin

The Summer 2023 release of the Color Splash Collection is in!

Made from wood and painted in acrylic paint, each necklace is uniquely painted and secured with a silver wire. The color pallet is rich and drawn from nature. The wood is rough cut to give a natural, unrestrained look and feel. Look below to see each necklace in detail.

Sea Foam

Lava Flow

Night Ocean

Red Night

Summer Pond

Orange Sunset

Night Waves

All jewelry made at HipMonsters is crafted and designed by kids. Each is made with love and inspired by nature, science and a love of creating something new.

Happy creating, and wearing!

Herbal Potions

July 9, 2023July 9, 2023 Lutin

One of the small projects that we do is make herbal potions, tiny jars or pouches full of crushed up herbs and flowers from our herb garden. They keep away the spiders and smell very nice. We also use some of our dried herbs for cooking, to give the food more flavor.

We grow lots of herbs in our yard, so when we trim the branches, we can dry them and put them in jars to be used for potion making. Make sure to label the jars so you don’t forget what they are filled with.

You don’t want to add lavender into your potions instead of rosemary! We also use some of the dried roses to make herbal potions because they smell very good, but they are much harder to crush.

After we finish grinding them up, we carefully pour the herbs onto wax paper, or in a tiny jar. If you pour them on wax paper, make sure to fold it carefully so the herbs don’t fall out. We also tie them up securely in twine after folding them. If you put them in jars, use a funnel or a rolled up piece of paper to make sure that you are pouring into the jar, not onto the table

This it what they look like when they are done. You can gift them to a friend, keep them, or use them for cooking.

Happy creating!

The Making of the Hand of Glory

July 9, 2023July 9, 2023 Lutin

Inspired by Harry Potter, we made our own Hand of Glory out of Foam-Mo and paint for Halloween.

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.

Foam-Mo is a foamy clay that we use for many of our projects. It is great for making organic stuff like plants and animals. After it dries, you spray it with a plastic coating to make it last longer. You can paint over the plastic coating.

For our first attempts, We used our own hands as a model to make them, but we felt like they didn’t look very much like magical objects. They were also very flat and 2d looking, not like the real hand of glory at all.

For our final hand of glory, we made the fingers more long and skinny to make it both more realistic and creepy. To get the shape, we rested it over a bowl to dry. We also added more texture to make it look more like dry skin instead of making it smooth. We also defined the knuckles more to make it more creepy. like it is trying to grab you. We also added more of a wrist to make it more like it is in the movie, and so we could easily mount it.

Once we finished the hand, we made a wooden stand for it to be mounted on. We stained it and sanded it to make it look distressed, and made a wooden plaque. We attached the Hand of Glory to the stand by screwing it in.

DIY hand of glory — The completed Hand of Glory

This is it completed! It is a great addition to our Halloween decoration cabinet, just don’t touch it, unless you want it to grab you.

Happy Creating!

Wooden Deer Sculpture

July 7, 2023July 15, 2023 Lutin

This is our wooden deer sculpture, made as a Christmas present. We only used wood from our yard to make it more meaningful. We always save leftover wood, so we can use it in our woodworking projects instead of wasting it.

DIY Wooden toy deer

This is the back view of the deer. As you can see, we attached the tail, limbs and antlers by drilling holes and fitting them into the holes, like a peg. We attached the head and the neck by drilling a smaller hole inside the neck and the body, then used a strong piece of aluminium wire to connect them together. To make the tail look more realistic, we rounded the end of it and drilled the hole at an angle instead of straight down.

DIY Wooden toy deer

The head was made from sanding part of a tree branch. We chose that branch because it already looked like a deer head, so we didn’t have to work on it very much. It even had little indents for the eyes! All we had to do was sand it, trim the ears, and drill two small holes for the antlers.

DIY wooden toy deer We attached the antlers of the deer by taking small branches from our birch tree and putting them in the holes that we drilled on the head. The antlers were very important because it would help people recognize this as a deer. We had to find branches that were strong so they won’t break, but small enough to look realistic. Luckily, birch trees shed a lot of branches, so it wasn’t too hard to find perfect branches.

Happy Creating!

Making a Toy Bunny

July 7, 2023November 15, 2023 Lutin

It was the end of the school year and we want to make a toy for one of our teachers. She loved bunnies and Beatrice Potter, so we thought that we should make her a toy bunny.

First, we drew a design for the toy bunny. We wanted it to be able to move its legs and ears so the design had to have a lot of details. It make sure it could more we used balsa wood for most of the parts to the bunny put together with nuts and bolts.

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.

Here is a picture of us cutting the wood. We had to use a fine saw because the balsa wood split with the Japanese saw.

Next, we drilled holes for the nuts and bolts. We don’t use wood screws because over time they loosen and damage the wood if the toy is played with it. To drill the holes we used a bench press and a secured the wood carefully. Because Balsa wood is so soft, it couldn’t be hand drilled.

After all the parts were cut, drilled, and sanded it was time to assemble!

Assembling a wooden toy bunny

If the plans are good enough, once you have the pieces done, it is like assembling a puzzle!

Assembling a wooden toy bunny

We made the ears out of plastic because the wooden ears broke too easily. We could also easily cut the plastic to be whatever shape we want.

To finish it off we added a purple pompom for a tail. And here is the completed bunny with a scarf!

Because it is posable, you can change how it looks year round!

This is what it looks like when it’s finished!

Happy Creating!

The Making of Number Five

February 13, 2023July 9, 2023 Dryad and Harpy

Inspired by the Boston Dynamics robot videos, steampunk art, and Girl Genius, the HipMonster team set out to make their robotic dog walk to take for a walk on our city street. This project ended up being a lot harder than we imaged and took two years to complete. This greatly impacted our work on the HipMonsters’ website which is just now being updated with new content. So, finally, we give you the making of Number Five!

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

Getting started on a DIY robotic dog projects — Getting Started

Base supplies to get started:

Brass Pipe Fitting, 4-Way Tee, Female Pipe (1, 1/4″ x 1/4″ x 1/4″ x 1/4″ NPT)
Brass Pipe Fitting, 90 Degree Barstock Street Elbow, 1/4″ Male Pipe x 1/4″
Brass Pipe Fitting, Barstock Tee, 1/4″ x 1/4″ x 1/4″ NPT Female Pipe
Black Steel Pipes ,close nipple pipe, 1/4 in. x 8 in, Black, 5 Pack
Black Steel Pipes, close nipple pipe, 1/4 in. x 6 in, Black, 5 Pack
Black Steel Pipes, close nipple pipe, 1/4 in. x 2 in, Black, 5 Pack
Hex Nipple Coupling Set – 1/4-Inch NPT x 1/4-Inch NPT,Solid Brass, Female Pipe
3/8 Inch Stainless Steel Cable Clamp
90-degree Swivel 1/4-Inch Male NPT x 1/4-Inch Female NPT
Clear 6mm OD 4mm ID Polyurethane PU Air Hose Pipe Tube Kit 10 Meter 32.8ft
Pneumatic Rotary Lever Hand Valve 1/4” N PT Air Flow Control 3 Position 4 Way
Pneumatic 16mm Bore 150mm Stroke Air Cylinder Double Action
Bike Pump

Building on our experience creating Number Three, we used piping to build the skeleton for the robot. To make it stronger to withstand the force of walking we used 1/4-inch steel pipes and pneumatic pivot joints rather than PVC tubing. After that, we assembled the legs using the pivot joins to allow the legs to move.

Assembly begins on a DIY robotic dog project. — Assembly begins!

After the legs were completed, we built a spine to help attach the legs and provide an attachment platform for the batteries, controller, and engine.

DYI robotic walker skeleton is coming together — The skeleton is coming together

When Number Three moved, the legs would frequently come loose so we made sure to be attached tightly to the spine. We knew from other robots we built that the vibrations of a running robot tended to unscrew bolts and screws. So, getting everything put together as tight as possible is essential.

Final tightening of the frame of the DIY walking robot dog — Final tightening of the frame

The spine takes a little patience to screw together because we used three parallel sets of pipes for strength. It proved difficult to screw them in at the same time and the best approach was to take it slow and calmly.

Side view of the completed DIY robotic dog skeleton — Side view of the completed skeleton

This is the side view of Number Five with most of the pneumatic pistons in place. We had two powering the back legs and four to power the front legs which did most of the pulling. We found from the full-scale test pull was better than push for control. If a front leg got stuck and the back legs still pushed forward the robot would veer to the left or right.

Below is a top view. The front part of the skeleton does not have a spine. This was originally to enable us to adjust the strides of the legs but that ended up being too finicky and we instead locked them in place. Sadly, we don’t have a clean attachment point for a head if we ever want to add one.

Top view of the completed DIY robotic walker skeleton — Top view of the skeleton

Next, we started connecting the air tubes to the pistons. We first laid out how the piston would attach to the frame then cut the tubes to link them to the engine. We made sure that they were long enough not to get yanked out, but short enough not to get caught in the robot’s legs.

Fitting the pneumatic tubes to power the piston on the DYI robotics dog — Fitting the pneumatic tubes

The tubing took a few attempts to get the length right. It is better to be too long than too short, so we have a bag filled with little bits of extra tubing. The tubing connects the piston to the engine. In the beginning, the engine was a bike pump powered by a kid but the final version would have a car air pump.

While attaching the pipes we recommend color coding the pipes with a little bit of nail polish or colored tape. You want the legs to be connected oppositely. If a right piston is rigged to push when the air is redirected, you want its mirror to pull.

Each piston has two connections:

one at the top which makes the rod push out,
one in the middle pulls the rod back.

Below is a gif of two pistons connected in opposition. This will enable the robot to walk with a stride.

Testing the pistons on the DYI Robotic dog. — Testing the pistons

Below is the first full-scale test. We used a bike pump to better control power. The bike pump worked remarkably well for most of our small-scale tests and was significantly quieter than the air pump. Plus it is cool to power a robot with a bike pump. As you can see… this test failed hilariously.

First test of the DYI robotic dog. — Test number one

The first test showed that controlling double-jointed legs was very difficult so we decided to shorten the legs as well as do tons of additional modifications. With lots of tubing, it tangles easily and it is hard to figure out where the problem is. We also added knees to stop the legs from overextending and falling.

Setting up the tubing on the DYI robotic dog — After tons of modifications

The second full-scale test was much more successful and operated as we expected. This floor has a slight downward tilt but it also works in the opposite direction; admittedly a bit slower. It is still operated by a manual switch but the engine is now a car pump.

Test number 2 of the DIY robotic dog — Test 2

At this point, number five was powered externally and controlled with a manual switch. Our final goal was to be able to walk number five in our neighborhood on Halloween, so we added batteries, electronic air flow controls, and a remote control.

Adding wiring and remote control to DIY robotic dog — Adding control units

The engine was an old portable air compressor for car tires that was super light and used little power. To make Number Five portable, it needed to run on a 12-volt battery which meant all the electronics had to run off of 12 volts as well. Luckily 12 volts is the standard power supply so finding the right parts wasn’t too difficult.

Adding pump to DIY robotic dog — Adding the engine

At this point Number Five was completely self-contained and controlled by a remote. We moved the battery to the center of Number Five to give it a lower center of gravity. When we first put it together the first time it was clear it would fall over easily if the battery was on top. So we quickly built a lower platform that rested between the leg. The pump was light enough to stay in the back clear from the movement of the front legs.

DIY Robotic dog walking, Made by kids

Here is the first test of the fully remote Number Five. We had more slippage than we had in the prior tests; the weight of the battery and air pump impacted the wheel traction more than we expected. So back to tinkering…

The key improvements this time were:

A rubber wedge in the wheels made them only spin in one direction
Shifting more weight forward.
Extended the forward stretch of the front legs giving a lurching motion forward that was very effective on flat or downhill surfaces.

DIY Robotic dog walking on sidewalk — Taking Number Five for a Walk

After the modifications were complete, the sister team was ready to take Number Five for a walk in our neighborhood! Number Five worked well on the rough city sidewalks and could even manage to walk up a slight incline as shown in this clip. Downhill Number Five went almost too fast. We have learned a ton and stay tuned for the next modifications!

For high res videos of Number Five in action check out our YouTube Channel!

Happy Creating!