Robotics, Hip Monsters, Page 2

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!

We saw the need for a new robot for halloween, so we made one. This is our steampunk squirrel powered robot Number Three. We wanted it to be as big as a kid to help with our Halloween decorations. Our other robots were small and not easy to see. Our plan was for a big robot with lights and room to grow as we came up with new ideas.

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.

Getting started on steampunk inspired robot — Getting started

These are some of the parts that we used. We gathered most of it from unused parts from other projects. This project ended up being a great way to recycle old parts and scapes and it made it look even more steam-punky.

Odd and ends for the steampunk inspired robot — Scrape parts

We used PVC pipes for the skeleton of our robot because its strong and lightweight. Also we had fitting from remodeling that would attach to the pipes and let us hangs details. The pipes are standard so if we did need to buy anything it would be easy.

Completed steampunk inspired robot — Completed Robot

The image to the right is the completed robot. The starting images ended up not as good as we expected so the final image was the best to show how the tubing was used. First, we cut the pipes to the right size using one of us to figure out lengths arms, legs and spine. Then we assembled it and added feet to keep it stable as we worked. The feet were harder than expected to get the right balance and weight. We used concrete bolts with extra washers as needed.

Then we assembled the PVC pipes and painted it with two coats. The first was sliver; the second was bronze. Next, we used an old security camera mount and attached a plastic jar on the neck. We added a toy squirrel inside and a few parts that looked like little controls for it. We named the squirrel Professor Brookenhoff.

For a fake engine core we used an old battery powered lantern connected to an old water bottle.

Building the gear box for the steampunk inspired robot — Assembling the gear box

Now we started on the fake control box. To make is steampunk we used gears and only a few wires. Then we assembled the gears to control the robot. We used old wood as a base and stain and distressed it by hitting it with a hammer.

After that, we drilled a bunch of holes on the back and put thin, long bolts through them to create a framework for the gears. Before we assembled it we laid out the gears on the table in the pattern we wanted then transferred the gears to the rig. You must remember to lay out the gears in the opposite way you want them in the rig.

Gear box side view for steampunk inspired robot — Side view of the gear box

Here is a view of gears completed with the control boxes on each side.

The gears took the most time and ended up being a lot harder than we imagined. It was difficult to screw the tiny nuts into place to give it a 3d look. Also, the bolts proved to be sharp. We attached some gears to the side of the control boxes so it would look like they actually controlled the gears.

Close up of the gear box to the steampunk inspired robot — Close up of the gear box

Then we attached a box to run the wirer through. We had a plan on the gears, engine, wire, pistons that we made before we started work that was our best attempt at design an honest working robot. The things we added is what Number Three would have needed if it was real.

Side view of the gear box for the steampunk inspired robot — Side view

We then added a second box next to the gears for attaching the control wires.

Close up of the gear box for the steampunk inspired robot — Close up

Here is a close up of the gears. Getting a 3-D design is important to make it look real. Each gear needs two bolts. One on top and one on the bottom. Make sure they are tightly screwed together.

Back view of the steampunk inspired robot — Back view

Now we focused on putting on details that would make it look like Number Three could move. Since it was supposed to be steam powered we used four left over pistons. We attached pneumatic tubing to the pistons then attached the other end to the engine. The idea is the power from the engine would create steam, and Professor Brookenhoff would give commands to the gears which would send the steam to the right piston to make it move. The idea of the head came from Carmichael from The Umbrella Academy.

Feet for the steampunk inspired robot — Close up of the feet

As we added more details to Number Three, we also needed to add more heavy things to the feet for stability.

Close up of the head of the steampunk inspired robot — Close up of the head

A close up of Professor Brookenhoff piloting Number Three.

Close up of the chest of the steampunk inspired robot — Close up of the chest

A close up of the tubing from the engine to the joints.

Side view of steampunk inspired robot — Side View

Number Three from side view. Here you can see the hands which also ended up being hard to make. Finally we made the hands out of wires and springs so it can hold things.

Front view of steampunk inspired robot — Front View

Here is the completed Number Three.

Happy Creating!

Tag: Robotics

The Making of Number Five

The Making of Number Three