Barrel roll

barrel-roll

Slightly dissassembled view of barrel roll.

Currently there are some issues with this project

TODO

• Fix the pcb to have the correct footprint

What is this

Barrel roll is a 150g combat robot that has a 2.706693 inch long bar spinner. There are two options for the microcontroller of the robot. Right now I have a pcb designed with a RP2040 in mind. I also have a version of the schematic/firmware with an esp32 as the microcontroller.

Why I created this

I created barrel roll because the way I got into robotics/programming/stem in general is through watching various battlebots-like shows and videos on the internet. So for a long time, I wanted to create my own battle bot. Once I saw the Fallout event by Hack Club I decided that it would be an amazing opportunity to create something similar to what got me into this in the first place. My goal with barrel roll is to create a bar spinner battle bot that could compete in the 150g weight class.(not necessarily well)

PCB

Above are the images of the PCB version of the electrical components of the robot(To be honest right now it feels more like a glorified pinout board)

Above is a picture of the pcb using DIP sodering. The schematic is the same as the original SMD sodered PCB.

The above is a picture of the schematic for anyone using the DOIT esp32 devkit v1. I made this one because it could cut down on the cost of the project as a whole.

Assembly

Onshape link: https://cad.onshape.com/documents/4d0cf8c11fd66439fc3e30b0/w/a8064dfad10d7d33689fe150/e/62081654516d84e6ca0ee160 A note about the assembly: I could not find 3d models of the bearings I wanted to use so I made a model with the same dimensions as the bearings. /n

As a note I intend on using the PCB SMD BOM.

PCBs/Electronics

For this project I made several usable versions of the electronics. I did this to make sure that when it comes time for me to actually build this I can still build it even if I don't have some of the equipment that I need. The main distinction between all of the options are the different ways to soder on the microcontroller. For the no pcb method you could just use an esp32 instead of a xiao rp2040.

PCB SMD

IF you are using a PCB to create Barrel Roll then you need to get the Gerbers.zip from barrel-roll folder in the repo. After this you need to go to your preferred PCB manufacteror of your choice to have it manufactured. Gerbers.zip You could use this as a reference for SMD sodering the xiao RP2040.

PCB DIP

If you are using the DIP version of the pcb then you need to follow many of the same steps as using the SMD pcb method. However, since you are using DIP for the RP2040, sodering the PCB should be significantly simpler. Gerbers.zip

No PCB

If you are not using a PCB your costs will be a little bit lower since you don't need to by the PCB. To find the wiring diagram you can look in the barrel-roll-nopcb folder of the repo. This is a kicad project that contains a wiring diagram if you have a DOIT ESP32 devkit 1(The esp32 from the electronics kits that commonly come from hackclub events).

Assembling the weapon system shell

In order to assemble the weapon system properly you want to make sure that you place the parts on the axle in the correct order. Axle stopper, Weapon with bearing, Axle stopper. Then you need to place the axle onto the two pieces on the Side shell. Here is a picture of the front assembly that you should try to replicate.

3D printing

To assemble the barrel-roll you first need to print out the parts specified in the onshape document. All the parts in the FINAL folder must be printed There will be a note with the quantity and the infill amount. The fillament for all of these will be up to you. I will personally be using TPU. If you do not want to go into the Onshape, All of the final .step files will be in models/FinalParts.\

You need to print:

• 1 BodyFinalPart1.step Link
• 1 BodyFinalPart2.step Link
• 2 n20motorToWheel.step Link
• 1 ShaftCap Link
• 1 WeaponDirectDrive.step Link
• Weapon Cap Link

Assembling the shell

For context:

.Step File The above is the main shell .Step File

The above is the side shell For the rest of it you should look at the onshape document.

To assemble the Main shell with the Side Shells you can use the bowtie connector along side the fastening rod to attach each part of the SIDE_SHELL without the use of metal connectors. To do this, follow the instructions below.

• 1. you first need to slide the shell into place directly into the bowtie connector. The next thing you want to do is slot in the pin connectors into the respective hole. video. (Yes I knbow the video is outdated I made the video before making a bunch of design changes relating to the side shell.)
• 2. After this you want to slide the shaft onto the side piece. The next thing that you want to do is attach a shaft cap directly on the inside of the side shell. video.
• 3. You need to slide the weapon onto the shaft. Next you need to slide the other shaft cap onto the shaft. video. After you do this you need to attach the belt to the timing wheel of the weapon.
• 4. The next thing that you need to do is you need to repeat step 1 for the other side of the case. With this you are finished with the shell assembly.

Assembling the weapon motor system

Assemblint the weapon system involves, using the weapon motor screws to secure the motor to the side of the shell with the "shield" like so . Next to finish securing the weapon onto the motor, simply slide the weapon onto the motor shaft then place the cap onto the motor shaft like so . With this you are almost done with the weapon motor system. n/

The next thing that you need to do is slide the shaft into the bearings. Before doing this you need to cut the (90mm) shaft into a 60mm shaft.(The reason for this is to cut down on the weight and to to make the shaft super long.) An alternative to this would be to print out a similarly sized rod out of ABS or petg Here

Electronics

For the electronics you want to reference the Schematic and the . First you want to wire the drive motors to AOUT and BOUT pin holes respectively. Do this for both of the drive motors. The next thing that you want to do is attach the motor driver to the respective pins. Next you have to attach the ESC motor controller for the brushless motor. Next you have to soder the jumper wires to their respective ports based on the schematic of the pcb. The schematic should have all the pins that you need to soder to.

Usage

To use barrel roll you need to connect the radio recever to the radio sender. After this you should be able to control the robot using your controller.

BOM

There are three BOMs one for SMD, DIP and one if you are simply using a esp32. The "master" BOM can be found here BOM(This will be the most convienient to use and will be the most updated in the coming months.)

BOM for PCB

Here is the .csv for the BOM

BOM if you are not using a PCB

Here is the .csv for the BOM

BOM PCB-DIP

Here is the .csv for the BOM

Poster

Poster