Encore v2 · Project X004
An abandoned redesign of the original Encore t-shirt cannon robot.
Overview
Encore v2 was an abandoned redesign of Encore, my original t-shirt cannon robot. Encore v1 was my first robot project, so a lot of the design issues came from having very little robot design experience at the time.
The goal of v2 was to keep the general idea of Encore while improving the main mechanical areas I noticed after building the first version. These included barrel pivot stability, overall bulkiness, Geneva drive driver alignment, and the way the barrel articulation system was packaged into the robot.
The redesign tried to reuse many of the same parts from v1, including the Geneva drive driver, barrel, 80-20, and other existing components. This made the project more of a practical redesign than a completely new robot.
Outcome
Encore v2 was abandoned before becoming a finished robot, but it was still a useful redesign exercise. It helped me evaluate my first robot with more experience and understand what I would change if I rebuilt it.
I would be happy to resume this design in the future or use it as the starting point for an Encore v3. With what I know today, I would likely keep a similar barrel superstructure and Geneva driver mount to v2, but redesign the barrel pivot around a section gear or lantern gear system on a 2-4" OD aluminum tube dead axle structure.
Problem & Goal
Encore v1 worked as a first robot build, but it had several areas I wanted to improve after gaining more design experience.
The main areas I wanted to improve were:
- Barrel pivot stability
- Overall robot bulkiness
- Geneva drive driver misalignment
- Barrel articulation packaging
- Superstructure size and appearance
- Tank mounting quality-of-life issues
- Limited design-for-manufacturing experience in the original build
The goal of Encore v2 was to redesign the robot around a stronger, cleaner, and more compact mechanical structure while reusing as much of the original system as possible.
Design Requirements
- Improve barrel pivot stability
- Reduce overall bulk compared to v1
- Create a smaller and cleaner barrel superstructure
- Accommodate a new articulation mechanism
- Reuse the existing barrel where possible
- Reuse the Geneva drive driver where possible
- Reuse 80-20 and other existing components where practical
- Create a stronger base superstructure
- Improve the Geneva driver mount to reduce misalignment
- Improve SCUBA tank mounting for easier use and better safety
- Design the robot with better build and manufacturing practices than v1
Process
- 1Reviewed the biggest improvement areas from Encore v1
- 2Identified barrel pivot stability, bulkiness, articulation packaging, and Geneva driver alignment as major redesign targets
- 3Planned which v1 components could be reused
- 4Modeled a new barrel superstructure in SolidWorks
- 5Modeled a chain-driven pivot concept
- 6Strengthened the base superstructure
- 7Improved the Geneva driver mount concept
- 8Planned improved tank mounts
- 9Archived the project after getting busy with college and pursuing other projects
Technical Decisions
- Reused the existing barrel concept to avoid redesigning the entire launching system from scratch
- Reused the Geneva drive driver while improving its mounting structure
- Reused 80-20 and other existing components where practical
- Used a chain-driven pivot concept for improved barrel articulation
- Redesigned the barrel superstructure to be smaller, cleaner, and better suited for the new articulation mechanism
- Strengthened the base superstructure to better support the pivot and barrel system
- Planned better tank mounts for safer and easier use
- Focused on better design-for-manufacturing practices than the original Encore build
Redesign Approach
Encore v2 focused on improving the major mechanical systems that made v1 feel less refined than I wanted.
| Area | v2 Direction |
|---|---|
| Barrel pivot | Chain-driven pivot concept |
| Barrel support | Smaller, cleaner barrel superstructure |
| Articulation | New mechanism packaged into the updated superstructure |
| Base frame | Stronger base superstructure |
| Geneva drive | Stronger Geneva driver mount |
| Tank mounting | Better tank mounts, not pictured |
| Reused parts | Barrel, Geneva drive driver, 80-20, and other existing components |
Chain-Driven Pivot
One of the biggest planned changes was replacing the original barrel articulation approach with a chain-driven pivot. The goal was to create a more stable and controlled barrel movement system while still keeping the mechanism realistic for the team to manufacture.
The chain-driven pivot was meant to improve the barrel's support and reduce the instability I experienced with v1.
Barrel Superstructure
Encore v2 included a redesigned barrel superstructure. There was not necessarily anything wrong with the previous superstructure, but the new version was smaller, looked cleaner, and better accommodated the new barrel articulation mechanism.
This was one of the biggest visual and packaging improvements in the redesign. The new superstructure made the robot feel more intentional and helped move the design away from the bulkier layout of v1.
The updated barrel superstructure is one of the parts of v2 I would still consider carrying forward if I resumed the project or created a v3.
Base Superstructure
The base superstructure was also redesigned to be stronger and cleaner. Encore v1 was bulkier than I wanted, so v2 aimed to make the lower structure more rigid and easier to assemble while supporting the new pivot and barrel system.
This was part of learning how to design around manufacturability instead of only designing around whether something technically works.
Geneva Driver Mount
The Geneva drive driver was one of the components I wanted to reuse from v1, but the mounting needed to be improved. In the original robot, the Geneva driver had alignment issues, so v2 focused on creating a stronger mount that would better hold the driver in position.
A more rigid Geneva driver mount would make indexing more reliable and reduce the chance of the mechanism slipping out of alignment.
Tank Mounting
Encore v2 also planned to include better tank mounts, although they were not pictured in the CAD screenshots. The goal was to make the tank easier to mount, remove, and secure.
Since Encore was a pneumatic t-shirt cannon robot, tank mounting was both a quality-of-life issue and a safety consideration.
What I Learned
- How to evaluate and redesign an older robot after seeing its real problems
- How to improve barrel pivot stability in a larger mechanism
- How to design a smaller and cleaner superstructure around an existing mechanism
- How to package a new articulation system into a robot redesign
- How Geneva drive alignment affects reliability
- How to reuse existing parts while still improving the overall design
- How to design with better build and manufacturing practices than my first robot
- When to archive a project instead of forcing it forward without enough time
