The original mock-up (middle pic) is held together by magnets, spring clamps and gravity.  The bender worked well, but after welding it all together (left pic). I discovered that the detachable handlebars (middle pic) were too far back, so I did a quick mod (right pic) using some leftover wheelchair sections.

   NOTES:

- The wheelchair armrests become the front bumpers in the above left girl pic - shown better here -

- The above right two pics show the "quick change, anti-tip" training wheels - from the wheelchair.

- The shopping basket is a Supercycle bicycle basket from Canadian Tire.

- The handlebars and grips fold down - from the wheelchair.

- The finger controlled smooth joystick ball was "plasti-dipped" in liquid rubber and is now thumb operated.

- The joystick controller is clamped to the right handlebar and can be easily moved to the left handlebar.

- The originally horizontal motors, are now vertical.

- The machine adds 4 inches to the rider's height, making it an easier "high shelf reach" for many shoppers.

- The large, normally rear drive wheels are now in the front and the front casters are now in the rear.

- To reverse the forward/backward direction, I just swapped the original location of the two drive wheels.

Princess Auto in Kingston, Ontario,  August 2013

Home Hardware in Napanee, Ontario,  July 2015

So I bought a cheap foldable battery powered electric wheelchair and disassembled it. Then I designed a whole new frame to stand on, which would accept the wheelchair motors, wheels and welded tubing.

I did not own a 1" tubing bender so I had to design and build my own. The above picture shows the radius cutting tool I built to cut a perfect 1/2" radius groove in the 6" round block of steel, then I cut another 1/2" radius groove in a 2.5" round steel block. To drill a perfect 90°, 5/8" hole in the workbench, I positioned my drill press in the right photo (NOTE - the sand bag damping and the red hydraulic jack, locking the drill press base to the work bench which is bolted to the concrete floor) and installed my bender, below.

After noticing the mobility problems my late mother had in her eighties with two artificial knees and an artificial hip, I began to think about personal transports.

"Mother is the Necessity of my Invention."

There are many high tech personal transport marvels out there, including the grandfather of them all, the Segway, introduced in 2001.  After watching its assembly on a "How It's Made" TV show, I was impressed by the genius of Dean Kamen who's means and ability were beyond this poor backyard inventor.  Also, it did not appear that his quick, slick (and accident prone) machine was designed for mobility impaired "little old ladies".  A wheelchair was more my mother's "speed" but she resisted that thought as she (like many) did not wish to be seen as (and therefore feel) "crippled".  Besides, she could stand and move about a room.  She just needed something to increase her range.  That's when the idea hit me.

Why not  "re-invent the wheel"  chair?

 "The true difficulty is building the machine that makes the machine."  Elon Musk

Above pic and below right pic were taken inside, where -

"The camera flash made the normally inconspicuous conspicuity tape conspicuous."

In the following quote, Mark Twain compares the Mergenthaler type setting machine to the complex Paige Compositor, into which he had invested, and eventually lost, his life savings.

At this time, both machines were in the middle stages of experimental development.

"The Mergenthaler, although slower, was simpler, less expensive and occupied less room. There was not so much about it to get out of order and these were immense advantages."   Mark Twain  (1890)