Since I've entered this project in the 2020 Hackaday Prize (UCPLA non-profit category), It's worth reviewing the judging criteria to make sure I've got everything covered.

First, here's a link to the actual Competition Submission video:   

According to the rules, the first step is to be included in the Entry round.  

Entry Round: At the close of the Entry Round Period, a panel of qualified judges
appointed by Sponsor will select up to one hundred (100) submissions to advance to the
Final Round based on the following four (4) evenly-weighted judging criteria:

1. How effective of a solution is the entry to the challenge it is responding to?
2. How thoroughly documented were the design process & design decisions?
3. How ready is this design to be manufactured?
4. How complete is the project?

In my case I've submitted my project for:
The Best Nonprofit Solution, sponsored by United Cerebral Palsy Los Angeles (UCPLA).  

Their open challenge is for High Quality Tools and Devices For Creative Expression:

Cerebral Palsy is a group of disorders that affects movement, muscle tone, or posture.
Generalized symptoms appear during infancy or in early childhood and include impaired movement, abnormal reflexes, involuntary movements, unsteady walking, trouble swallowing, or eye muscle imbalance, which makes it difficult for both eyes to focus on the same thing.

This challenge seeks new designs for adaptive tools like tripods, workstations, trackballs, or joysticks that can be made affordable and open source. The purpose of these designs is to give individuals with cerebral palsy and/or other physical challenges greater independence in their lives. 

So.. It's time to self-evaluate, and see if I'm covering the goals of the evaluation criteria.

1)  Effectiveness.

Since the basic action of walking can be difficult for a person with CP, my project addresses the specific problem of powered mobility.  My assumption is that any creative task is made more difficult if the person is tied to a single location, and is dependant on others to help them prepare work areas, collect materials, and take breaks.  By providing someone with greater mobility, they can have greater independence and are able to take on more creative challenges.  

Another key creative outlet for young children is play.  Role-play and other social interactions will always be more interactive if the child has mobility, so my goal is to reduce the cost of powered mobility for young children with CP.

Being a technology designer, I felt that my best contribution would be devising a low cost, yet reliable way to add powered mobility to a wide range of wheeled assistive devices.  My rationale was that many people could address the mechanical aspects of making a wheeled chair/stander/car/walker, but not everyone was capable of adding a joystick controlled power drive that was safe and easy to use.

Throughout this project I have taken different paths, and tried different approaches.  I have eliminated unnecessary complexity where it wasn't beneficial, and I am honing in on a very elegant and versatile approach.   

My theory that a hoverboard could provide a very cost efficient drive system was proven to be correct, and the bluetooth joystick controller that I have created provides an extremely flexible interface, which can be used with a wide variety of adaptive controls.  My software focuses on safety, and adaptability.

I have demonstrated that a hoverboard can be adapted to Medical Grade devices as well as DIY wheeled devices.  If you put a chair on wheels, my hoverboard hack can make it mobile.

2) Documented design process

Each of my major design approaches or decisions has been documented with a project log (there are currently 12 logs).  Wherever possible I have included the rationale for my decisions, live demonstration videos, construction photos, code descriptions and cad files.  

At the beginning of the project I created a hyper-linked index of project logs.  As I add each new log, I update this index.  My goal is for anyone to be able to easily find elements of this project that interest them.

I started out with a selection of code repositories and files, but I have recently combined the various components into a single Open Source Github Repository.  This contains Hoverboard Firmware, Joystick Interface code, schematics and PCB designs, as well some CAD files for basic metalwork.  

3) Manufacture

Whenever I embark on a meaningful project, I always assume that at some point I may want to reproduce it, so I will always opt for Engineered components rather than makeshift.  I invariably end up re-using components on latter projects so this inevitably save me future time.  For example, if I'm developing an electronic circuit, I always quickly transition to a manufactured printed circuit board rather than a proto-board.   

In the case of this project, I have already produced three iterations of two different printed circuit boards.  Consequently, the Eagle CAD files for manufacturing the latest BluJoy Joystick controllers are included in the new combined github repository.

Likewise, I hand cut two custom mounting plates to adapt the hoverboard to the Jenx Multi-stander.  But once I had verified the dimensions, I drew up the plates using Autodesk Inventor, and shipped the files to a Laser Cutting shop to fabricate several more sets of plates.  I now knew that I could replicate this generic mounting system and use it on a wide range of devices.

4) Completeness.

The concept for this project has been through several major direction changes, and the current implementation is in the refinement stage.  

The primary output of this project is a modified Hoverboard, combined with a wireless Joystick interface board.  These are the essential components required to adapt a wheeled device to a motorized device.  The secondary output of this project is a range of recommended implementations (instructions/hacks) that show how the primary components can be used in specific applications.

The primary system components are in slightly different states of completion:

        a) Hoverboard Firmware: Well developed and stable.  Complete.

        b) Joystick Software: Basic Functionality complete.  Still needs expanded features.

        c) Joystick Electronics: 2nd Generation ready for testing.  

        d) Joystick Mechanical:  Off-The-Shelf solutions working.  Needs more innovation.

The tasks that remain are:

        1) Add features to Joystick Firmware:  Multiple Speed Modes, & Analog Joystick.

        2) Explore new joystick designs to enable more gross movement.

        3) Document the process of breaking down the hoverboard and adding the mounting plates.

        4) Finalize the DIY Mobile Car Seat concept and produce construction docs.

5) Future Plans.

If Prize funds became available, they would be used to create "Mobility Kits" that could be requested by hackers to motorize an Assistive device.