This week we have been working on the projectile feature of the robot, as the original idea of firing nerf bullets is shooting them too fast and is unable to get them to drop into the top of the tank because the angle is wrong..
So, 2 members of the group spent their time designing the system of which projectiles could be flung off the robot into the Feed the Fish tank made last week. They started designing this concept based on the following loose design of a trebuchet- a medieval throwing machine.
Based on this Pavle began working on making a trebuchet like design to throw projectiles. He started designing this on CAD.
Another member worked on designing the projectiles that would be launched. He used Autodesk fusion to create two hemispheres as seen below, which can be glyed together after being 3D printed
Pavle also worked on laser cutting the sensor holder after designing it on CAD- here is the image of this being cut:
We 3D printed some of the projectile hemispheres as shown below:
Marin worked on printing the 2cm diameter circular projectiles from the Autodesk CAD design and then glued them together to make this :
Dhruv has been working on the code for the positioning of the robot for shooting the projectile balls designed earlier:
He also worked on the servo trigger for the shooting of the projectiles. Here is his code:
Akshat worked on fixing errors with the remote control but still has somethings to fix.
Robot club is on Easter holiday for 3 weeks now and will be back on 26th April
This week Pavle worked on assembling and gluing together the feed the fish obstacle course using the CAD model developed by James as guidance.
He also used tape to mark the robot’s position and we tested where the bullets were going to shoot, however currently they are shooting too hard, so we will look at a solution based on a Trebuchet instead.
Aarav has produced a CAD model for the 2cm diameter balls that the trebuchet will fire. We will 3D print them on the school 3D printers. Marin has been working on the text for the blog.
Dhruv and Akshat have been working on the infrared sensor programming and have fitted a new camera to the robot after the previous one failed last week. They have also been working on setting up the mic to control the robot. Akshat tried to do this on a pi zero but he could not get it to run so he has taken an old pi 1b home to try on that.
Everyone is very pleased to be able to run robot club back at school again for the first time since the last lockdown.
During this week Dhruv and Akshat worked extremely hard to add to the code to use infrared detection as well as ultrasonic for position sensing, thus enhancing the robot’s skills.
James and Aarav have been working on drawing the fish bowl in Autodesk Fusion CAD, that will be part of the pi wars at home competition course. We tried initially to use the one on the website but the scaling was coming out wrong and it would have been 4 meters high instead of 40 cm. We should be able to laser cut it from 6mm ply next week.
Marin has been looking at the garden path course and attempted to print out a paper version of it with help from Pavle. It is slightly undersize but will do for testing. The white gaps have been coloured in now with a black sharpie.
Pavle helped to change a faulty motor for the robot and covered a white 3D printed block with green vinyl. We now have blocks of red, green, blue black and white.
Akshat repositioned the grabber arm while Dhruv tested the grabber arm so that it captures the block
Here you can see the grabbers holding the green block.
While working on the robot this week the camera has failed so we may have to try to get a new one for next week.
Just a couple off members managed to log in to the virtual robot club this week.
We now know that our year 9 club members will be back in school on the 10th March, so we should be able to restart the physical robot club at school again on Monday March 15th. We will therefore hold one more virtual robot club on March 8th.
In the meantime, Dhruv hopes to do some more work on the IR sensors, and to check if all the motors are working ok now.
We talked about the contest course that we need to build when we get back to school. We want to have a black floor and walls, with white 19mm tape for the track for the “Up the garden path” challenge. We have access to some cardboard but will see if school DT dept can supply some thin ply or hardboard which would be better.
Over half term Dhruv has managed to replace the faulty servo on the front grabber and also install the replacement pi camera. He has done some code for the forward looking IR sensor and developed some code to connect the speech input to the motor controller.
Akshat has done some work on developing the line follower code, but needs access to the robot to test this.
The plan is for the “up the garden path” challenge is to have the robot doing autonomous line following but supplemented by voice commands to start, stop and turn right or left at the junctions. That should get us plenty of points !!
We are limited on what else we can be doing until we can get back to school in March.
We also had a chat about the Mars rover landing and the helicopter on board. There is a very good youtube presentation about it at
We are continuing as a weekly virtual robot club on Microsoft Teams
Akshat has been working on the voice input and recognition system which will use a separate pi held by the user which will then send the commands to the robot. He needs access to the robot and details of the IP addresses to be able to finish setting this up and to test it.
We have decided that we will try to drive the robot with voice commands for the explore challenge, but will look to have remote control as a backup
Dhruv has the robot moving up to a fixed distance from objects using the ultrasonics, but has not had time to fit and test the new pi camera as yet
James is looking at ideas for the explore course
Aarav is helping to get blog text together
We talked a bit about the new Raspberry Pi Pico board. Our tutor is attempting to have a pico controlled line follower robot working by next week, using one the UKMARSBOT chassis built by the club members last year
We are hoping to get back to school in early March so that we can be more productive and work on making the physical items for aspects of the challenges
We have got some new parts to replace some faulty one. A couple of servo and a new Pi camera. Our tutor has also 3D printed a couple of 50mm blocks in red and blue, so we just need a green one now.
One member of the team is looking at options for the obstacle course and one is collecting data for the blog from the others.
Two of our programmers have made progress on developing the ultrasonic code to detect walls and blocks
Because the microphone on the pi is picking up a lot of robot noise we have decided to move the voice input onto a separate Raspberry Pi which will be with the person in charge of the robot. Once the voice input has been recognised this can pass the data to the pi on the robot using a wireless socket connection. One of our programmers will be developing this code.
We spent part of this meeting looking at some of the sessions from the Pi wars virtual conference
To give us something else practical to do for everyone, our tutor is going to set up a virtual line following contest on roboton.io
We can develop our python line following code online on the Roboton site and run a virtual competition – probably over the Easter holiday
School is locked down so we have decided to run a virtual robot club on Teams at 6pm on a Monday until we can get back to school. One of the students has taken the robot home with them so we are able to do a bit of work on it. This week we were just thinking about what we needed to do and how we might be able to do some of it.
Not having access to the school laser cutter will limit some of what we can do.
We have circulated the details of the Pi wars virtual conference for any of the students who want to look at some of the sessions
James has offered to try to 3D print a 50mm block for the tidy up the toys challenge
We have just had an email saying that the schools competition is being moved back – so we now have until 24th June to run our robots and submit the videos
In this week, many new parts were fitted to hold items in place such as the fan, the raspberry pi camera, the 16 by 2 I2C display and the battery.
CAD models of these holders were used to generate STL files that were then used to print them on the 3D printer
Here is the CAD model for the servo controlled grabber arms that fit on the front of the robot : A slight modification was needed to remove a part of them so that they would open fully without hitting part of the main chassis
This image below is after all the holders were printed and then all parts which need holders were added to the robot. You can see the 16×2 LCD display on the top and the block grabber arms at the front with the camera mount just behind them.
One member spent his time designing the obstacle course the robot will travel in.
The programmers managed to get the grabbers working – but we had to replace one faulty servo. The controller and motors were combined in software so now we can drive the robot forward & back with the wireless gamepad style controller.
Two other boys have been working on the Nerf bullet firing mechanism this week.
We now break for Christmas this week, so will be back with more updates in January