Introduction: Windtrain Umbrella
What if the power of the wind could be harnessed to travel? What if anyone could produce low-energy, modular, wind-powered vehicles? What if new technology reconnected us to the power of nature, to ancient technologies?
Windtrain is a modular shape-shifting vehicle that is intended to be capable of carrying heavy things with very little energy, using wind power. A hybrid of a train and a sailboat of some sort. Several versions of the WindTrain have been built already to demonstrate the concept of " Protei": Windtrain " Mister T", " Baltic", " Heads or tails", " Ace", " MakerCamp", " Farting Flamingos" (last one documented on Instructables). This is Harbour School G4B version of WindTrain, we called it "Umbrella" - inspired by the domestic accessory. It is radio-controlled. It comprises of 4 modules for a total length of 536cm, width 126cm, height 180cm. It an educational project to introduce to students the use of tools, fabrication, collaboration to prototype wind-powered machines. Further prototypes are coming. This project was developed at MakerBay, Hong Kong Makerspace and taught by Cesar Jung-Harada, Harry Churchill and Edward Ip Chi Ching with the Harbour School teachers. The introductory presentation by Cesar is here as a google slides.
This is still an early prototype and has many issues. On step 10, we explain the resonance issue we have and how we intend to fix it. We would love to have your comments and suggestions how to improve our design and increase the performance of the Windtrain.
Step 1: Drawing, Presenting to Class
We made a drawing to plan our design. We made a model that was made out of cardboard to check . We made a paper sail and tape it to the cardboard model. We made cardboard wheels. We looked at the model that G4A made, the " Farting Flamingo". Then we drew our new version of the WindTrain. We added new ideas to improve the model. We shared our ideas to our classmates and teachers. Then we got into small groups and combined all our ideas into a second draft. After the second draft, we made a small sample version of our ideas.
Step 2: Create Groups. Combine Ideas
First, we all have our own model design, then we decided that to choose the best part our models and put them into one model. We designed a sail boat shape WindTrain with a triangular base, one sail and three wheels.
Step 3: Inspiration From Umbrella
We found inspiration looking at an umbrella. We used the same design and lightweight materials as an umbrella. We built similar parts on the WindTrain. This design of a wind train is that it can fold into a smaller size and be easy to carry.
Step 4: Model Made of Cardboard, Plastic Bags, Paper and Tape
We kept working on the design, thinking particularly how the modules could be attached to one another.
Step 5: Plastic Bag Sail Test
Before we scale in size and building multiple modules, we tried a "prototype of the prototype". The sail was made out of a plastic bag. It worked decently well during the test, so we decided to move forward.
Step 6: Look at the Models. Plan Out the Next Steps
We looked at our cardboard models. We decided on the best parts for our final model. The next step is when we took our design and decided what materials to use to build our WindTrain. We decided to build it out of wood, Aluminium bars, fabric, string, motor, rubber wheels and wires. We split up into 3 groups, one group was in charge of wood, another of metal, the last one of textile works.
Step 7: Parts List, Technical Drawings, Laser Cutting File
- Laser cutter
- Sewing machine & kit
- MakerBench (hacksaw, drill, file, sanding paper, measuring tape, ruler, hot glue,
- Technical drawings
- Aluminium 8mm ø hollow rods (structure)
- 4.5mm plywood (joints)
- Rollerblade Wheels with low-friction bearings
- Steel wire (temporary pins, would be 3mm nylon screws)
- Golden fabric
- Nylon String for the sails
- 2 channels radio controller
- Bamboo Toothpicks (prototyping)
- Cardboard (prototyping)
- A lot of masking tape
You can find attached here all the laser cutting files.
Below, the 3d model of Windtrain "Umbrella"
Step 8: Make!
We started building our WindTrain on Wednesday 2nd and Thursday 3rd March 2016. We worked in different groups. The different groups were cutting wood, sewing fabric, and cutting metal. Each group was responsible for a different part and assembling the parts together. We took one day to measure and design all the parts and another day for assembly and testing.
- Sam H, Chanti, David
Step 9: Indoor Observations
On our last day tested the WindTrain. First we tested the front WindTrain with the remote controlled front steering. We used a big fan to move the WindTrain forward. It moved very fast and was easy to steer. There was nothing to change on the first test. Next we were ready to test the whole WindTrain. We added the next 3 cars to test. The train did not move very far or fast. It was too heavy for the fan. We changed the angle of the train so the front train could get more wind. This allowed it to move faster and farther.
Step 10: Outdoor Testing
Finally, we brought the wind train outside to test with natural wind. There was not much wind so we pulled it around and someone steered with the remote. The WindTrain worked well and we were happy with our model and design. It was nice and light and collapsible.
As you can see in the video, while being pulled the first module of the WindTrain is nice and sturdy, but the 3rd module wobbles a bit, and the 4th module wobbles a lot. After a bit of research, we found that this phenomenon is called mechanical resonance. We selected this videos to explain this phenomenon, several of them demonstrating with the Barton pendulum:
- Video 3: If you want to understand the science of resonance and harmonics
- Video 4: Explains energy transfer between linked pendulums
- Video 5:.How frequency influences different structure depending on their elasticity
- Video 6: Barton Pendulum
In further prototypes we need to build structure so they are less resonant, provided by better mass distribution, damping, less elasticity in the structure.
Step 11: Documentation
With all the students, we assembled around a big table and we documented each of the steps. We wrote together this instructable you are now reading :)
Step 12: Conclusions
Friday March 4, 2016: It’s the last day of MakerBay. Most people feel sad but others feel normal. We had a blast planning and building our WindTrains. It was a very complicated and detailed project. It took us a whole week to put it together and the results were really awesome.
We asked people what they learnt in MakerBay. The whole class learnt at least one thing in Maker Bay including drafting plans, using power tools, assembling different parts, and testing models. We all had fun but some say they kind of had fun. Ms.Wong says ‘‘I hope the class had lots of fun. The improvements the class could make would be listening better’’. Mr. Weizer says we could improve on teamwork being respectful and following directions. The whole class says “we could improve on building more stuff”. G4B would like to say a big thank you to Cesar, Edward and Harry for teaching us this week. We learned some really cool stuff. Thank you, MakerBay!
- Charlotte and Kwenzi