Introduction: Three Wheel Bike Kinetic Sculpture

About: four tires and wheel? you've got yourself a deal

Hello! Welcome to a project that took many elements, much thought, and an enormous amount of FUN

The direction of the project changed throughout its construction and it ended up being an award-winning Kinetic Sculpture in the 2015 Baltimore Inner Harbor Kinetic Sculpture Race (KSR)

A kinetic sculpture is self-explanatory: it's a human-powered vehicle that is dressed up to look like art and has to navigate different obstacles like mud, water, and hills. Some sculptures are much more fantastic than others, but the event is a great time and I wouldn't miss it.

There are races throughout the country every year, but the races aren't the only places you will see these silly things; they can be found at the Burning Man celebration, in High schools, and in tinkerers' back yards

This tale begins with the idea to build a big, reverse recumbent tricycle that had nothing at all to do with Kinetic Sculptureism. There was no direct, clear-cut plan as to what the trike would look like when it was finished, but I can say that it had inspiration from this splendid instructable as well as bikes and bike parts I had lying around my little workshop.

The trike then transforms from a working recumbent to a even better-working Kinetic Sculpture after more people started helping with the construction. Our vehicle was then redesigned to be able to go up hills and through the water.

Things to keep in mind while reading/seeing this instructable

• This was my first project that involved welding (I bought a very cheap stick welder (Never failed me!)) so don't expect pretty welds that look professional
• I will purposely not cover every detail of the construction because I don't want people to build exactly what I did (make your own, unique version!)
• I probably didn't have enough mechanical/bikeanical knowledge to dive right into a big project like this, but I did anyway
• If you notice the surroundings of the vehicle are different in the later pics, that is because it was moved (not easy!) to a different, better equipped shop
• There are probably better Kinetic Sculptures out there

Step 1: Materials and Tools

This project will require a pretty extensive array of tools as well as materials. Keep in mind I have no clue what the final cost of the Sculpture was.

Warning: This project requires welding, grinding, lots of saws, and probably other notably dangerous devices. If not used properly, you could get hurt. Be careful but have fun.

I will try to put together a rough parts list of what I used, just keep in mind to make your version unique and different!


1. A welder of some kind (I used an AC arc welder as well as a MIG welder when we switched shops)

2. Power tools like a grinder, jigsaw, abrasive cutoff saw, power drill, the works

3. Basic workshop hand tool assortment (screwdrivers, sockets, wrenches, sand paper, hacksaw, files)

4. Welding hammer/ wire brush

5. Bike chain tool


1. A couple lengths of 1" black steel pipe for the frame ( very heavy stuff, maybe not such a great idea)

2. Several old bikes (I think I used 3, bought them at yard sales for around $10 each

3. 2 solid-tire wheelchair wheels and the bolts to use as axles for them

4. We made spindles out of these, I don't know what they are supposed to be used for, but they had "U" shaped pieces in them and thats what we needed

5. Many, many lengths of 1/2" CPVC to make the frame for the fish's body as well as "T" and 45 degree connectors to make connections in the ribs

6. A big roll of plastic mesh net

7. A bigger roll of thin, rubber mesh net to make the scales and face of the fish (it is blue and works great as a semi-flexible shell for Kinetic Sculptures)

8. 3ish cheap table cloths

9. Pink insulation foam to use here and there (fins and jaw)

10. A completely ridiculous amount of various colored spray paint (we must have gone through 30)

11. A few lengths of 1/2" EMT conduit was used to make some strong, "key" ribs as well as the tail

12. Pool noodles really come in handy when adding the art factor of Kinetic sculptures because they can be used as many different things (our fish's lip is made of them)

13. Whatever you wish to make your seat out of

14. A chain idler

15. A couple sheets of 1/4" plywood to make fins and the tongue out of

16. Various types of hardware (we used a combination of brass and galvanized nuts and bolts)

...Plus whatever you need to make your Kinetic Sculpture unique!

Step 2: Dive in (Build the Frame)

To begin this big fish, I built the frame from 1" black steel pipe because it was the strongest weldable material that wasn't crazy pricey. The frame was a simple, triangular arrangement that had a 24" bike fork on the back for the drive wheels. Since this was going to be a tadpole arrangement trike, the front was a wide piece of steel to put the steering wheels on.If you want to make your frame from a material like PVC or PVC itself, don't. I actually gave it a try with 1.5" schedule 40 and gave it several gussets, but it was far too weak. I would strongly advise making frames from weldable steels or aluminum.

To build the frame, cut the pieces with an abrasive cutoff saw and grind the ends so the pipes fit together, this is called fish-mouthing the pipes. Also make sure to grind all the paint off the ends of the pipes to make sure the weld is strong. After that, link the tubes together with your welder. I added a seat backrest column behind the back of seat so it supported the passenger when pushing on the pedals. Then, I connected the seat tube of the bike fork on the very back to the seat post column with the top tube of a donor bike.

To finish the frame, I drilled holes on the ends of the front tube for the king pins and the spindles.

I think that's about it for the frame...

Step 3: Keep Going (Drivetrain)

After I completed the frame, I decided to tackle what I would do for the driveline. I knew this would be difficult because of such a long chain I had to keep tension in. Getting the chain from the pedals all the way back to the drive wheel without rubbing against anything was a feat. I went through several different designs for the chain idlers including tubes for the chain to go through as well as several different pulley formations. In this section of the instructable, I'll touch on what I found to be the best way to create the drivetrain.

I studied pictures of real recumbent trikes and others projects and how they routed the chain.

To create the driveline, I first sawed off the bottom bracket from one of the donor bikes and welded it to the center tube of the frame after placing it where it was comfortable to pedal. I didn't even touch the primary shifter that was still on the donor bike's seat tube because I wanted to reuse it. Then, I linked all three donor bikes' chains together using the bike chain tool. After the chain was put together, I began to test different idler designs. I started with a series of small metal tubes for the chain to slide through, and this worked decently, but the chain would slowly tear a groove in the metal and it eventually broke. It also created an unwanted noise. The next design included one of the chain pulleys from a donor bike attached to a flat steel plate coming from the frame tube on a "U" bolt. This worked very wheel compared to the previous, but the chain would consistently fall off the pulley wheel. It needed a track on both sides of the pulley's teeth so the chain had no where to go. We also needed to do something with the returning chain which has no tension.

What we did was buy a full power chain and returning chain idler from terra trike. This had two wheels, one with teeth and both with track walls that prevented the chain from falling out of place. The two wheels were attached to each other and they went on the same axle. The idler was attached eventually to a piece of 3/4" square steel tubing that attached to the frame with the same "U" bolt as before. That "U" bolt was actually welded to the frame because the plate that was supposed to hold it on kept bending.

The gearing of the vehicle was not going to work with the stock road donor bike gearing. The gearing was too high. This could be solved by giving the drive wheel a mountain bike cassette (smaller gears)

That pretty much covers what makes it move

Step 4: On to Steering

After the drivetrain was taken care of, I set out to design a steering system for the trike. At this point, the trike has been being worked on for around a month. I knew the steering wouldn't be an easy task because it doesn't act like bike steering so bike parts aren't able to be used.

What I first thought I could do for the steering was a cable system with two pulleys. The cables (the green paracord) would be tied to the steering arms, go around the pulleys (some washers on another "U" bolt) and finally tied to the steering handles. The steering handles were made from an old folding moon chair that I cut up and found pieces of steel that were the right shape. This cable steering worked for a while, but I wouldn't recommend recreating it because there was nothing stopping the cables from slackening, and then they would be too long to have precise steering.

To create the steering system that actually works, read this:

What we ended up doing was creating a system of push rods that were connected to the steering arms and the steering linkage. A hole was drilled in the center of the steering handle as well as in the frame. This was the steering handle pivot point. From the steering handle come two push rods, one on each side that connect to a steel plate coming at a 90 degree angle from the steering arms. The steering arms are then connected with a steering linkage. The steering knuckles were made from those brackets that there's a link to in the parts list. After some grinding and welding the arms onto them, they worked great as knuckles. 3/8" brass bolts with nylon lock nuts were used as kingpins. 1/4" galvanized bolts with nylon lock nuts were used for all the pivot points of the linkage and push rods.

To make the push rods and the linkage, I took some EMT conduit and bought some cheap go kart tie rods and extended them. I welded nuts into the ends of the pieces of conduit, and bolted the tie rods to the nuts.

This steering system proved to be reliable and accurate.

Step 5: First Test Drive

After the first design of all the components was complete, I decided to embark on the first test drive of the trike. This was before most of the components were improved, so the test was not very successful. The trike made it a whole mile though! When it came back, it was time to redo some stuff...

Step 6: Begin to Build the Sculpture

After the vehicle was a workingish moving platform to begin working off of, I set out to turn the trike into a big fish to match our Kinetic Sculpture team's other fish. There was much debate and discussion over what we wanted the fish to look like in the end. So, instead of having a exact idea of what the thing would look like in the end, we just made it up as we went along.

We started wit the fish's skeleton which was going to be made out of 1/2" CPVC. We chose CPVC because it's more flexible than PVC and we didn't want our fish to look like a box. We had five main horizontal ribs for the fish. The ribs are connected to the main frame with pieces of 3/4" square steel tubing (same as chain idler) and the ends of the pipe just sit in the tubes. The tubing is welded to mounting points all over the main frame. We also added cotter pins through the ribs and their mounting points to anchor them in place. The bottom two ribs connect at the very front of the vehicle to form the bottom jaw. The ribs are connected to each other throughout the skeleton with CPVC "T"s and 45 degree connectors. The second level of ribs have connectors with arced pieces of pipe going to the other side to create a curved top for the fish. Make sure to allow for head room! Keep the ergonomics of the vehicle comfortable because if you are going to compete with it, it's an all day race.

After the CPVC frame was complete, we thought about what we would do to skin the fish. We started by putting a foundation skinning of a thin plastic mesh netting all over the frame. The netting was attached with small zip ties on the CPVC skeleton.

Before we started putting scales on the fish, we covered it with cheap gray table cloths with more zip ties. This created a smooth surface to attach the scales.

Step 7: Scales!!

Once we thought we were ready, we started to put scales on guppy. This process took a long time and much energy but we were very satisfied with the result. I would recommend using this method when making outside shells on Kinetic sculptures.

We started with a material that was foreign to me prior to making this sculpture. It was a very thick, blue, rubber mesh that was flexible and strong. I don't know what the material is called (I didn't order it!) but I'm sure it won't be hard to find.

To make the scales, we cut the mesh out in the scale-shape we wanted. It took two layers of the mesh per scale, and this created a shimmering pattern when they were placed on top of each other. Also, since the top and bottom layer of each scale was a different color, they made an appealing contrast. After we made (cut out) very many of these scales, we attached them to the fish. We did this by zip tying three our four ties per scale through the scale, table cloth, and plastic mesh, making sure the ugly end of the zip tie was on the inside of the sculpture. One person had to be on the outside pushing the zip tie through, and another on the inside tightening the zip tie. When applying them, we made sure to overlap them in the right direction so the front of the fish didn't look like the back.

Still more to come but getting there...

Step 8: Make a Face

Once we liked the way the scales looked, we needed to give this guppy a face so it wasn't just an ugly table cloth.

Making the face was easy. We draped a big piece of the same material that we made the scales from over where we knew the face was going to go. We then marked off what we needed to cut out, then we cut off the excess. After that, we experimented with facial colors and ended up liking a red over a blue layer. This created a nice, deep red for our fish's face. We had to add a few more scales around where the edge of the face met to make it not such a clear-cut line where the face met the body.

At this point we really started to like the way it was going to turn out.

Step 9: Make It Float

Part of the Baltimore KSR involves having the vehicles go through the Inner Harbor (WATER). This actually wasn't as big of a challenge as we thought because guppy was pretty light and it only had to carry one passenger.

To make this fish float, we looked at it and decided where the places we would put the flotation devices. We decided we would put flotation devices under the jaw and fin-flotation around the rear wheel.

To make the flotation devices, we glued together three pieces of 2" green foam board and cut out our shapes, then we attached the devices to the fish with 1/2" EMT conduit and glue. We hid the front one under the jaw so it didn't have to look pretty, but we painted the rear ones to look like fins.

Sorry for being short on pictures at this step, we were getting excited to see it when it was finished.

Step 10: Accessories Time

The fish is nearing completion, but still needed a few things...

1. We needed to make the lower jaw surface; to make this, we cut the shape out of 1/4" plywood and painted it bright red, then we glued to to the top of the front flotation device.

2. The top of the fish looked too empty, so we made a fin from 1/4" plywood and a Styrofoam sheet to give it a little more dimension. Supporting the fin is a piece of 1/2" EMT conduit coming from around where the pedals are connected to the main frame. (this turned out to be right in front of the driver's face, so much for ergonomics!) The fin is then attached to the conduit with cotter pins through pre-drilled holes. We ended up painting the fin orange

3. We needed to make a tail for this thing. What the tail would look like sparked much debate among the team and it was difficult to come to a conclusion. What we finally did was add a piece of steel tubing that fit inside the seat tube of the bike triangle on the back of the main frame and weld a piece of rebar through holes in it. The rebar created the perfect post to make the tail from, and at the right angle. The tail itself is the same material that we made the scales and face from hung from a long, curved piece of 1/2" EMT conduit with zip ties. We then added orange pieces of the material in a stripe formation to give it some color contrast.

4. EYES!! We wanted the eyes on this fish to really pop out and give it character. We decided the best way to make them was to start with cheap dollar-store plastic bowls and paint pupils on them. We painted the fish's scleras (white part) yellow to match other colors on it. (we were starting to make too big of a variety of colors on guppy) The pupils on guppy are NASA logos (don't ask)

5. LIPS!! Like the eyes, we wanted the lips on guppy to get attention. They are simple to make, paint pool noodles your desired color (yellow again was ours), cut a groove in them with a utility knife, and put them on there!

6. Bubble machine... why not?

Step 11: The End

Well well well, looks like this guppy is looking pretty finished. After a few more road tests and some tuning, the fishy was ready to go with barely any time left before the race.

The race was for the most part, a success. Guppy and guppy's big brother, Rainbow fish made it through thick and thin. Whether it was hills, water, or mud, these fish were tough as nails. (weak nails)

They ended up earning the Art award at the 2015 race and are most likely going to compete again next year!

Please visit here for more pictures of our completed fish and a look at many other sculptures!

Step 12: The Future...

I wanted to add some designs for a few more vehicle platforms that could be built. Maybe they could be inspiration for future Kinetic Sculptures!

Thanks for reading!

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