This is another design that is at the top of my 'Why didn't I think of this' list...
Check out the video below showing this brilliant design for an electric powered hand cycle attachment for a wheelchair.
Well done... well done :)
Hit the link at the bottom to review the Amazon page featuring the Firefly Electric Attachable Handcycle for Wheelchair:
• Firefly electric attachable hand cycle for wheelchair
• Converts your manual wheelchair into a 10mph speed machine!
• Go the distance with a high-capacity battery that lets you travel over 15 real-world miles (24 km) on a single charge.
• Get there quickly with a powerful and quiet hub motor that climbs the hills for you.
• Remove the strain from your shoulders, maneuverable, easy to control direction even on side slope.