Very late one night, our mentor Kevin had a vision of a can grabber that would use a rope to squeeze a pair of Lexan arms around a can. Herr Profesor Doktor Urs worked with a few students to make this fever dream into a reality.
Aaron shows off our new recycle container grabber, design 2.1. The grabber arms are made of Lexan® reinforced with thin plywood sheets, with strips of grippy tread material bolted on. These arms hug the cans while the crank on top pulls the arms together by winding up the rope on a central shaft.
The team has explored the geometry of the problem, which calls for lifting the can five feet high to place it on top of 5 square bins. This grabber works for cans that are upside down, right-side up, and even sideways. A can on its side is top-heavy, so when the grabber holds the can near the bottom and lifts it, its off-balance grip causes the can to rotate onto its top, after which it can be picked up in its upside-down state and put on the stack.
The Bit Buckets spent a good bit of time today working on getting the new elevator put together.
We finally got the new holonomic drive base running! This robot is rather nice. Here it is, driving around on the Franklin Docks. It seems to handle the 2″ tall platform bump rather calmly.
We installed the elevator on the robot and added the pneumatic tilting system. Next up is getting the tote carriages installed and running.
We got some nice 3D printed spool for our elevator directly out of the Forbes manufacturing facility. Its our first prototype that will pull the carriages up in the elevator track by a rope that is windup onto this spool.
A thorough stress test was professionally conducted by Sparky.
Today after crawling out of bed and sleep walking to robotics we started to work on our new drive train and recycling bin lifter. We got to spend several hours watching the lasers cutter cut the drive train. Then we had to cram square nuts into wood using pliers for our ingenious drive train design. It was time consuming and tedious, but by the end of the day we were rewarded with a mostly functioning structure for our drive train!
Our other group got to work on motorizing our can lifter, which will run off of some bag motors and some chain. It looks like it is going to work very well, and we are all looking forward to see the completed version!
Xochitl used aluminum 1/2″ hex shaft, turned on the lathe to fit into bearings. One end had a further step to fit into an encoder coupling.
This was the first time the Bit Buckets had used Xerocraft’s Logan lathe to make robot parts, and we were very pleased with the results.
Before Xochitl could turn the shaft, she had to create a high-speed cutting tool, using the grinder.
Today after school we started work on the Bin lifter to allow us to stack the recycling bin on top of a stack to triple the score. We have made this a significant part of our team’s strategy and believe that it is one of the most important aspects of the game. Our design is based off of that of a garbage truck, so the can is placed upside-down on the top of the stack. This is not a problem because their are no rules about the configuration of the recycling bin. Also, it is heavier on the bottom so it actually more stable.
Linus did some soldering on the electronics panel of the practice robot. We are using connectors from the talon SRX controllers to the motors, so it’s easy to replace them in the field. We make the whole panel removable so that it’s easy to work on.
We also worked on the design of the drive train today and hope to be able to make it soon! We had a lot of practice designing drive bases out of laser-cut plywood in December. This helped us to quickly design a holonomic drive base.
It is day eleven of the build season and the bit buckets are keeping positive throughout all the many setbacks and sweet victories. There are a slue of tasks to be done including finishing the design of the robot, building and refining all the field elements, programming, configuring the electronics and public outreach.
A few of the students got to develop their skills on the lathe by making one (as well as an additional unusable one) of the four drive shafts the will be used on the drive train. They learned that there are challenges (like loose bits) that come with using a 90 year old lathe. The pictures below chronicle that journey:
Another group continued their work on the field elements—getting to explore the wonders of the wood shop and the fun of nail guns and table saws.
Linus continued his excellent work wiring up the control panel:
And the programmers, as always were 100% on task:
Last but certainly not least, the robot design also had to get done as well as some assembly work (drive pods etc.):
At dinner the bit buckets had a special treat in honor of the wonderful team President, Alia’s birthday:
The team will also be getting an awesome treat at the end of the week in the form of a movie night. The bit buckets will be leaving the comfort of their workspace on Friday and going to the movie theater to watch the great film, Spare Parts. The movie chronicles the amazing achievements of a Carl Hayden high school robotics team. The bit buckets have had the tremendous honor of working with Carl Hayden high school robotics students and is so excited to support them and see their stories played out on the big screen. Definitely check out the movie!
Today we did some work mainly with determining additional designs to the subsystems, especially the can-grabby.
For the can-grabber we added a structure to have it tilt up and down, like it will have to when attached to the whole robot, and tomorrow we plan to have it become actuated and powered by the new pneumatics system.
For the drivetrain, we wired the pneumatic components for controlling the can-lifter and other things that will need it!
And finally in terms of software, James continued to work on drive train code!
Let’s hope to get stuff done tomorrow!
Today was quite productive! To begin with we had a meeting where we started finalizing our robot design. We had some debate about minor elements like what type of drive we should use, but we have a general consensus about what the final robot will look like.
Then we started prototyping the Recycle Bin grabber. We went with a pneumatic powered claw type design. Its a very rough prototype, but a great start. Next we finished our human player station. It’s not the most pretty thing, but it gets the job done. It’s to spec and made of plywood. It is great, because it allows us to test how our robot picks up totes, and if we decide to use them litter, from the station. Also it lets us give our human player practice. It was a great day and I can’t wait to see where some of the things made and ideas presented in this meeting.
At the end of week one, our build is starting to take shape. With the design all but finalized, work on the code and prototype mechanisms can continue at full speed.
The robot prototyping continues as our design for a can grabber begins to take shape. The added friction from the wheels show here lets us more reliably pick up the bins, and the rotating join will allow the robot to flip the can over and achieve as high of a stack as possible.
The rest of the build is coming along nicely. The electronics board and basic drive code is finished, resulting in a successful test of the laser cut plywood drivetrain design we build during the offseason, and the rest of the field elements such as the tote chute are nearly complete.