SET UP.
A
B
C
D
E
F
MATERIALS
TOOLS
A. Plywood:
» ½" birch or oak, 2'× 4', 5 ply
minimum
» ¼" birch or oak, 2'× 2'
B. Gearmotor, 12V, windshield wiper
manufacturer part #F78U-17B571-AA.
Online sources list this as fitting a
1996–1999 Ford Windstar.
C. V-belt pulley, 4" with ½" bore
Grainger part #3X909,
grainger.com
D. Aluminum square tube, ¾",
8¾" length
E. Extension spring, 3¼"×
3"×0.072"
F. Tennis ball, regulation
No substitutions.
Gunther Kirsch
» Wood dowel, 1¼"× 20"
» Steel spacer for ¼" screw,
unthreaded, round, ½" OD × 1½"
long McMaster-Carr #92415A871,
mcmaster.com
» Battery and charger, 12V–18V
» Switch, SPST, on-off toggle
All Electronics #STS- 56,
allelectronics.com
» Switch, SPDT snap-action micro All
Electronics #SMS-196
» Rectifier diode, 1N5406
All Electronics #1N5406
» Hookup wire, 18–22 gauge,
stranded: red ( 3'), black ( 3')
» Blade connectors:
1" (or slightly
larger) female ( 2), ¼" female ( 2)
» Bolts, ¼-20: 1¼" long ( 3); 1" long,
round head ( 2)
» Bolt,
7-18, 1" long
» Bolt, M6, 6mm, 1mm/thread
× 60mm long
» Lock washer, 6mm
» Washers: ¼" ID × ¾" OD ( 9),
½" OD ( 6)
» Nuts: ¼- 20 ( 4),
7-18 ( 2)
» Wood screws: ½" ( 4), #6× 1½" ( 50)
» Metal screws, #4×¾" ( 5)
» Conduit straps, 1" ( 2) or pipe strap
» Nails, finishing, ¾" ( 4)
» Cloth strips, 1"× 8" ( 4)
» Wood glue
» Thread-locker fluid such as Loctite
» Masking tape
» Heat-shrink tubing
» Circular saw or table saw
» Jigsaw
» Hacksaw
» Tap and holder, ¼- 20
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