The Bulldogs Ri3D Megathread

Day 2 Recap starting!

Day 3 of Ri3D is on! This little robot is really coming along and will be playing the Infinite Recharge at Home Challenges this evening!

Robot Reveal and Q&A at 7:30pm eastern
Matches to start after at approx. 8:00pm eastern

Watch live:

Day 2 Recap with Q&A -

Fixing Common Issues -

It appears that the shooter changed from belt driven to direct drive. Was there a specific reason for this? Thanks. Great videos.

We made a design error with the belt spacing between the Falcon and shooter wheel, making the belt overly tight. This caused many issues, such as melting our 3DP pulleys or persuading the belt to jump off of them.

Due to time constraints, the simplest fix was just to direct drive instead of fixing the spacing.

I love you guys’ talking about how useful Git is, specifically in making it easy for teams to collaborate remotely.

Over at Full Moon Robotics we actually put out a more in-depth tutorial on how teams can use Git in their projects and the benefits of doing so - if you’re reading this thread and want to learn more about it, check out our video here!

2021-01-13_10h22_07 2021-01-13_10h22_15 2021-01-13_10h22_24

Here is some screenshots of the CAD. That is how it was designed to work, the PVC was used because we didn’t have the correct Polycarbonate tube in stock, so we used the PVC couplings to adapt to the 3D printed parts we made before hand.

The 3D printed part (in black) is 2 24T pullies with a 0.5" ID x 0.875" OD bearing, which is press fit into the part. This rides on a 0.5" round stock which is bolted into the side plate of the intake. The bottom intake roller has a solid axle to help the with rigidity of the intake.

We determined that the smooth PVC surface would be sufficient to pickup the balls, but could be improved with silicon self adhesive tape. This was not tested, as I was unable to attend RI3D on Monday due to a work conflict. If I was to redo the intake in a less time sensitive build, I would have expanded it to cover the whole robot width, as it can technically pickup 3 wide, it really only worked with 2 wide in combination to the V-hopper.

I did the design work for the Hopper/Intake/Shooter, so if you have any specific questions I am able to answer them.

The center distance was 0.1" under the calculated distance. I am not sure on why it was so tight, but if I did it over again I would router plates with various spacings to get a best fit. Because of the speed of the falcons, I wanted the belt to be pretty tight.

The big thing we were missing was supports for the rigidity of the shooter. With the configuration of the robot we were limited to 1/8" polycarbonate, we should have had more bracing which would have helped with the issues experienced in the practice matches we had in Monday.

The bearing setup is what I was interested in. How you are holding the bearing in the tube etc. We typically put the bearing in the lexan plate and it can be a challenge keeping the bearing in. So in your setup if the intake was hit the shaft would just slide out a bit but could not slide enough to make anything come loose.

Forgot to post some more videos:

Hyperdrive Challenge Runs:

Power Port Challenge Runs:

Robot Reveal - Nick. (what the internet named the robot):

2020 vs 2021 Robot Matches:

1 Like