This miniQuad build is meant for racing. My goal is to build a low-budget version of this:
Charpu’s quad is around 1000 € and I think I can achieve about the same performance with a fourth of that money.
I am using the same technique as I did with the big Quad V2.0. A sandwich frame, but instead of the round profile booms, I am using square profile because it is easier to make the connection between the carbon fibre bars.
One year ago I joined this amazing student team. DUT15 is the name of the car that 80 people worked on so hard to bring it to life. Today I am proud to say that we are the overall winners of FSUK 2015, on the Silverstone circuit and the overall winners of FSG 2015 on the Hockenheim circuit!
About the car
DUT is a 4WD electric car, each wheel being powered by a motor.
Total weight (no driver): 160kg
Motors: 4 x AMK 35kW
Accumulator: 7.2kWh LiPo
Acceleration: 0-100Km/h in 2.3s
From sketch to victory
I worked on the car as a part time Powertrain engineer. During the period of 9 months the entire team went through conceptual preliminary and detailed design, as well as manufacturing and testing. During the design phase, I was responsible for the water cooling system of the four motor controllers. During the manufacturing phase I was in the mechanical crew milling the suspension brackets and lathing the shafts of the car.
All in all, it was an amazing experience. I improved my design and manufacturing skills and most important, I had a lot of fun building this car!
I am creating the second version of the quad because I wasn’t happy with the performance of the first one. It was too heavy for the generated thrust. The 4 NTM 3536 motors were producing only 150% of the aircraft’s weight. That means the quad was hovering at 66% throttle which is not ok for my requirements, since I want to transport a 400g camera onboard.
My plan is to change the battery from a 3S (11.1V) to a 4S (14.8V) and change the propellers to generate more thrust. I also want to minimize the weight, so I am completely changing the frame structure. I am going again for a sandwich structure. I am using the 14mm booms for the main structure, which will be reinforced by the bottom and upper plates made of PCB. By doing this, I will also benefit from the copper paths and thus, have a distribution board for my ESCs.
The dxf files for the frame are my own design and can be downloaded for free from here under GNU license.
Few days ago I had the amazing opportunity to go to ‘t Harde, at a military base to launch few rockets. Among these was my team’s rocket (John) which was designed and build by Aleksandar Petrov, Chris Niemeijer, Aleksader Parelo, Hardi Njo and myself. The goal was simple, yet challenging: to fire up a rocket up to 1 km with an egg on board and land safely to protect the payload.
And this is what happened (video by Hardi Njo):
Unfortunately, the egg did not survive and that is because the parachute did not deploy, but we did achieve about 800 m of altitude as the rocket was quite stable. That is mostly because of a detailed design in OpenRocket where the CG and the CP were properly placed. Another reason might be the fins that were 3D printed at an accurate angle between each other. The parachute wasn’t supposed to be deployed using pyrotechnics. The cone was meant to be pushed by a spring out of the body. In this way, the airflow had only one job: to open the parachute. This did not happen because of the timing. The spring was released too early, when the rocket was few moments before its apogee and the aerodynamic force was still pressing the cone downwards.
The interesting fact was that the main body of the rocket survived, despite the crash at about 200 km/h with the ground. The conclusion: it was over designed, but it was a fun experience laminating it, layer by layer.
A new RC project is coming! This time, the achieved CAD skills from TU Delft helped me to simulate the entire model and therefore make the optimal design:
The dxf files for the frame are my own design and can be downloaded for free from here under GNU license. I chose to make the frame out of 2mm carbon fiber because I found cheap sheets on http://www.hobbyking.com. Unfortunately, I couldn’t find a laser that cuts carbon fiber sheets, so I cut them with the Dremel.
After few crashes, the flying wing V1.0 wasn’t able to rich the same performance as it did in the beginning, so I came up with V2.0 (not necessary better, but the build took only 1 hour) and I got up in the air again.
I was concerned that this project is never going to be finished, but here it is, a rear wheel drive buggy with front suspension!
After 2 years I decided to finish this project this summer. To be honest, not only did I slightly overtake my budget of €1,000, but I also had to work extra hours besides the 4 hours per day working schedule.
Nevertheless, a lap in this thing worths every single cent and time invested in it!
The project ended in a successful way, with the first prize of the national contest Infoeducatie 2013 and a special prize from Google. After a one week camp I managed to connect with different people working on very interesting projects. I got valuable feedback which I tried to implement quickly in order to improve my project. Here are a few pictures with Xtion Arm and with the rest of the competitors from Robotics and Software sections.
As I am qualified to participate to “Infoeducatie” National Contest, robotics section, I have started to build a new arm, 1:1 scale, stronger and which is capable of moving in 3 axis. In order to do this, I used 3 independent motors for the shoulder joint, one for elbow and one for rotation (in the biceps). In all, there are 5 motors (this model) 12 V DC, which I chose for its included gearbox with a powerful ratio (1:131) and as well as for its compactness.
Here are my sketches for the lathe man:
And here is the result:
For the skeleton, I used plexiglass as in the previous version, but this time a thicker one (6 mm). Here is the draft:
The following pdfs are exported from CAD. This project is open source, so feel free to cut your own parts using my sketches.