I built a 4-grocery bag sized trailer for my dad and his wife for his Jazzy Power Chair for warm weather grocery shopping. The basket is an Elfa shelf system #3 sized basket. I machined the 3-axis hitch (roll, pitch and yaw or turn) and trailer draw bar out of 6061 aluminum with a steel eye rolling in a 1018 steel pitch axis rotation pin. The trailer hitches up using the smooth shank section and head of a cut down 5/8″ dia. bolt and it is retained with a 1/8″ dia. hair pin. The 14″ dia. semi-pneumatic ball bearing wheels were bought from McMaster-Carr. The basket is attached to the axle/draw bar unit with small hose clamps whose tails are turned downwards to insure the interior of the basket remained totally snag free.