Dar Pedestrian Bridge (Inverted Version)

My name is Jacob Nord, I am 15 years old and I live in Klamath Falls, Oregon. I am in 9th grade and home-schooled.

I've been using Tinkercad for a while and it's been very useful to build different projects and develop ideas so I have some experience with how it works.

For a few weeks I tried working with Fusion 360 on this bridge, but it was not working well for me, so I've chosen to work with Tinkercad for all of my demonstrations.

I've read all of the 'official rules' and I've tried to incorporate as many ideas that will go with the rules...

I've always have wanted to fly a plane, and flight school is very expensive, so when I saw this contest I got excited and built a bridge hoping there might be a chance of winning so I can pursue my dream of flying.

If I had a 3D printer I would have printed out my design and made a small model bridge with a landscape for this contest, but I can't afford a 3D printer, so I used Tinkercad for the demonstration.

• Tinkercad

• $100,000+ 3D printing robot with GPS and Al technology ( If you so happen to have one )
• Plastic pellets - for printing
• Concrete - for the foundation blocks

• Internet ( I have poor internet, so I struggled with that )

There are some supplies that may vary...

After designing two other bridge designs, I tried to picture the bridge to be 'inverted', and built it on Tinkercad. Once I built it, I thought it would be a good design to add for the 'make it bridge' contest. It appears it can hold some more weight than the other two bridge designs.

This bridge design would hold the weight of the robot the whole distance as it prints it's way to the other side, and wouldn't need a temporary support such as a pillar or piling (Referred to on my first two Instructables, the links to the other bridges are at the bottom of the page. ). So, with this design, it will eliminate one step.

It didn't take me that long to build this specific design because there wasn't much to modify on the original bridge.

• The nice thing about this design is that it can be either lengthened shortened and/or widened on a Cad program and then 3D printed in life-size form and will still be plenty strong, therefore making it easy to make it fit into any location were it needs to fit. Other bridge designs usually require lots of engineering for a bridge to fit into a planned location.

• With this bridge it can be lengthened without needing a pillar underneath for support.

I wanted to incorporate "made with Autodesk Software" on the 'threshold' of the bridge so everyone knows how the design was made.

Here in southern Oregon there has been a harsh drought, and the farmers, the local Tribal members, and environmentalists, have been fighting over what little water there is in Klamath Lake. This is where farmers get their water. Finally after many years of little rain and water, this year we had lots of rain and the lake is now full and the irrigation ditches are full also, and everyone has water. Therefore I think this bridge would be a great way to "bridge gaps", even if in the future there is a drought.

• There is a big irrigation canal that goes right through town that would be a great place because people wouldn't need to go on the bridge where cars are racing on by. There are bike trails on both sides, a few hundred feet away there are grocery stores on one side and on the other side a few hundred yards away there are houses. So there are plenty of people to use the bridge regularly. (I have this bridge planned out in the same location as the very first bridge l put up.)

The idea of having a robot print it's way across a ditch or creek can be very efficient and quick when things go right. With the right equipment and ideas, it will make it even easier to print a bridge in the elements.

I have done some more research and found out that people want to have a robot print it's way to the other side on the bridge... I think there is a saying, or at least there should be one: 'One day you invent something new, just to find out it was just invented before you'.

Here is a list of things that might help with the bridge build on-site;

Required steps/supplies to accomplish the build efficiently:

• Have a vehicle to transport the robot and the materials needed to the job site.
• The vehicle should have a crane/boom to place the foundation or 'pile' to the right location. The robot then has a good spot to print off of.
• Equip the vehicle to be able to provide some concrete to pour into the plastic hollow foundation blocks.
• Have the vehicle to be able to re-charge the robot at any time and quickly on-site. Also the vehicle can carry additional tools for the workers to use to make different adjustments for the robot or the ground around the bridge location.
• Construct the pre-cast hollow foundation blocks to have magnets imbedded in the plastic were the robot will calibrate. This will enable the robot to know exactly where to start printing, thus allowing the robot to print the bridge very accurately.
• A mechanical grabber on the robot addition to the printing nozzle will improve productivity.

The list above just gives some ideas that could make 3D printing a bridge easier, quicker and more accurate.

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I also have some different ideas of elements that could be printed into the bridge.

• Carbon fiber string could be printed into the layers of the bridge adding extra strength to X,Y,Z axis.
• Mosquito repellent could be mixed into the plastic as it is being printed. (The oils that are in mosquito bracelets)
• Paint or dyes could be added to the the plastic to make different colors, patterns and themes.
• UV protective coating could be sprayed onto the bridge to prevent sun exposure on the plastic.

The ideas listed above are optional depending on where the bridge would be built, or how durable it needs to be.

The robot will need a GPS system, to allow the robot to print the bridge very straight and accurately. When the robot takes a break to go re-charge or re-fill on plastics, the GPS system will allow it to resume from the right location.

Having a GPS system programed into the robot will enable accomplishing the project quicker.

Carbon fiber string could be added into the melted plastic to add extra "stringth" (strength). The robot would push the string into/with the melted plastic as it is printing. This will give the plastic bridge extra strength, it will keep the plastic from chipping away when the sun breaks the plastic down.

(When the top walking surface of the bridge is damaged to a certain extent, it could be repaired with a machine that 'paves' the surface with new plastic. With thick plastic like this bridge, it would take a long time before the top surface needs to be repaired.)

Here in the Klamath Basin the mosquitos and midges get very thick and it becomes very hard to go out and enjoy the outdoors.

So l thought of how mosquito bracelets work, and looked into it. Natural oils are added into the plastics of the bracelets, and since the bridge is made of plastic, these oils could be incorporated into the material.

Because these bugs love the waterway where the bridge would be, the bridge would keep them away so that people could use the bridge without pesky bugs.

UV protective coating/clear-coat seal could be sprayed onto all of the surfaces of the bridge, this will make the bridge last a lot longer in the sun. Because this is a plastic bridge, it will definitely need a 'sunscreen' to make it last longer in the elements...

The mosquito repellent oils will need to be added into the UV protective coating also, in case the oils in the plastic can't go through it.

The robot could be programed so a person with a computer could make a custom, colorful/artsy design, and the robot will print it out exactly. Themes or crazy colors could be printed out for visual appeal, or make it blend into its surroundings such as, camouflage type colors and designs...

With the idea of colors printed into the plastic with a programable robot at your disposal, the sky is the limit of what could be colored/printed!

Check out the videos below that show all sorts of colors that could be added.



When the robot is printing across, manual labor will have to be involved. Before the robot has printed half-way across, the bolts will have to be bolted down. This will ensure the robot will make it across safely.

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The metal railing will have to be bolted down manually, once the bridge is fully printed.

This makes the bridge ready for people to start to use.

Then after a lot of steps... here we are with the finished product!

I think this would be a good bridge for our community because as l said before, there has been a lot of tension here in the Basin because there has been no water. But since there is plenty of water for everyone now this year, this bridge would be a good way to "bridge gaps", even for in the future.

This town is not a growing town, but a unique bridge would be a a good way to put Klamath Falls on the map.

I have really enjoyed the building process of this project. It seemed that it took a long time to build, and get to this point.

There was lots of videoing involved, editing the videos, taking screenshots, editing again, and writing this Instructable and editing that. So there was a lot of work put into this.

I'm not the best at writing, but I hope I have explained this bridge concept well enough to you.

You may see me put a few more bridge concepts/variations of this bridge or, other types of bridges in a few days.

I hope that this bridge will qualify for the contest and I wish good luck to fellow contestants, and happy building ;-)

Please check out my other bridge entries with the link(s) below:

https://www.instructables.com/Dar-Pedestrian-Bridge/

https://www.instructables.com/Double-Arched-DAR-Pedestrian-Bridge/