By Jack Horton

ORIGINALLY, I built this little machineas a child's de luxe toy; after a few

runs on it I realized it was a novel but prac-tical form of transporation.

It will do 15 mph and the range is around20 miles. I have driven my Electrobike asmuch as 11 continuous miles—enough toshow that it could be useful for errands andwould be great for an afternoon's fun.

Acceleration is smooth and fast, the mo-tor is quiet and the ride is vibrationless.Overnight charging with a $10 tricklecharger keeps the battery up for about 7cents per charge. A good battery treatedthis way will last more than a year. Abonus: the trickle charger has many otheruses. I often use mine for small electro-plating jobs.

What you need. Use a good six-volt golf-cart battery—but make it a good one, nota cheap 74-hour type or a 12-volt job. Thecells of a 12-volt battery are too small togive you a good cruising range. Any tricklecharger of four-to-six amps rating will do.

Use standard five-inch go-kart wheelswith ball bearings and three-inch tires. Donot use wheels with sleeve bearings; if yourwheels do not roll freely your motor willuse current needlessly. Use a 5/8-in. axle.

Don't use a bicycle chain for the drive. Itwon't stand up under this treatment. Use aNo. 35 roller chain and sprockets. A V-beltcould be used but performance would suffer.

The bicycle frame I used was a 20-inchjob and it took lots of body English to findroom for all the parts. A 24-inch bike framewould be ideal.

Exact dimensions are determined by thesize of the components you pick up. Wheelsand battery should be on hand when you

Build this

Electric ScooterForty bucks' worth of bike, car and motor parts will

give you a scooter for errands or an afternoon's fun.

DETAILS OF FRAME, FORK AND HANDLE BARS

FRAME with battery' motor and seat in-stalled. Rear fork is spread, reinforced.

WHEELS are go-kart jobs. Sleeve-bearingtypes would not perform satisfactorily here..

NOTE FOOT PEG on front wheel foot restbehind battery. Regular bike seat is used.

BRAKE is a standard go-kart type clampedon front fork with a pedal on the brake arm.

Electric Scooter

begin so you can fit them to your frame.Begin by cleaning the frame and re-

moving pedals and crank. Cut throughthe tube two inches ahead of the crankhanger. Heat the tube near the front-fork bearing and bend the tube downand forward to make room for thebattery. Cut a length of high-qualitysteel tube to join the two ends of thecut tube and weld it in place.

To the new section of tube, weld thebattery carrier—a rectangle of lightl x l-in. angle iron.

Use auto hold-down bolts to hold thebattery in the carrier and aircraftbattery caps to prevent spilling fluid.Snazzy but optional: a plastic battery

cover from a marine supply dealer.Forks must be heated and spread to

take the wheels; you can do this withtwo torches if you work carefully. If youaren't a welder a shop should do theframework for about $7.

If slots for mounting the front wheelcan't be enlarged enough for the newaxle, weld on washers with holes of theright size. Axle-bearing blocks of cold-rolled steel should be used on the rearfork (see drawing).

Cut iron-pipe spacers (or heavywashers) to hold the wheels in placebetween the tines of the fork. Use axlesof cold-rolled steel made to fit the wheelbearings and threaded to take nuts and

Electric Scooter

jam nuts. Mount the wheels and linethem up with a straightedge so theytrack properly.

Bend the handlebars, as shown in thedrawings, to accommodate grown-upknees. Use a standard bike seat; no fit-ting is required. Foot pegs are mountedon front axle and foot rests in thesprocket hanger.

Use a drive sprocket of about 60 teeth.Through it drill three equally-spacedholes to match the wheel bolts of yourwheels. This work must be done ac-curately if the sprocket is to run true.Use three spacers on long wheel bolts tohold the sprocket far enough from thewheel for chain clearance.

Use a standard go-kart brake on thefront wheel; simply mount a pedal onthe brake arm and clamp the brake as-sembly to the fork.

Fenders are optional. I happened tohave a sheet of heavy Duralumin lyingaround and I shaped the fenders fromthis. They are mounted like bikefenders.

The motor should have high torqueand low current consumption. Don't use

an auto starter motor. The motor I madefor the Electrobike has a maximumdraw of 60 amps in a stalled condition.To make one like it get a two-brush,

shunt-wound, six-volt auto generatorfrom an auto wrecking yard; also twofield coils from a six-volt starter motorfound on Chevy Sixes. Conversion con-sists of replacing the generator field coilswith the Chevy starter coils and rewir-ing for series operation.

Disassemble and clean the generator.Make sure all parts are in working con-dition. Remove and discard the fieldcoils but save the two retaining slugs orpole pieces. Grind or hack-saw thesepole pieces so the starter coils will slideon them snugly. Install new fields in thecase and tighten securely. The motor isnow wired for series operation.

The current flows from the insulatedterminal through the first field coil in aclockwise direction, through the secondfield in a counter-clockwise direction tothe insulated brush, through the arma-ture, grounded brush and ground. Cur-rent must flow through the field coils inopposite directions. Use bus bar to make

field connections. Flatten a copper tubeand use it instead of bus bar if you wish.Solder all connections and assemblemotor.

Next, install a ten- or eleven-toothsprocket on the motor shaft. The key-way is already cut. When testing, re-member that the motor speed dependson the load. The motor must not beallowed to run light—that is, without aload. Don't run it on your bench morethan a second or two.

The case of your new motor hasmounting flanges, so installation in theframe is simple (see the drawings). Usebicycle seat-post clamps to install themotor. Line up the motor sprocket withthe rear wheel sprocket and cut spacertubes of proper length to maintain thisposition. Chain is adjusted by a slottedsteel strap connecting motor and seat-post tube. Slotted strap is a standardauto part. The Electrobike has twospeeds and is controlled by push buttonslocated on the handle bars. The wiringdiagram shows the hookup. A singlespeed is all right, however, since filespeed can be controlled by on-and-offoperation of the button.

For a single speed, simply omit onesolenoid and the resistance. The lengthof the resistance wire for the two-speedjob is a cut-and-try proposition. Startwith 18 inches of 1/8-in. resistance wire.Form in a coil and connect as shown inthe diagram. Cut off an inch or two at atime until the desired low speed isreached. You'd best shield this coil be-cause it becomes red hot in operation.

The solenoids are six-volt Ford parts.The push buttons are two-terminalclamp-on type and, like all the electricalparts, can be bought at an auto partsstore.

Be sure to include a locking switch inthe circuit as indicated in the wiringdiagram; otherwise, some helpful citi-zen can be counted on to push thebuttons and send the parked scooter onits riderless way. A key-lock ignitionswitch works fine.

Drill and tap the frame at any con-venient location and mount the sole-noids, using small screws or bolts. Thisalso applies to the lock switch. The pushbuttons are located atop the handle bars

RIDE is smooth, motor quiet: top speed is 15mph—a reasonable pace for a young rider.To soup up the rig one might install an-other motor, supply power to both wheels.

under your thumb. Drill a pair of holesin the handle bars and run the wires in-side the bars.

With a little patient shopping aroundfor parts and making the most of ma-terials you should be able to build thisElectrobike for around $40, including agood set of kart wheels—essential forsatisfactory operation. Auto junkyardsand parts stores will have nearly every-thing you need. For things you can'tfind locally, try the classified auto andmotorcycle ads in MI. Ocelot Engineer-ing, 950 Kendall Drive, San Bernardino,Cahf., can also supply anything you mayneed.

Which brings us around to the paintjob. The original Electrobike. wasfinished in bright orange enamel andwith black wheels, seat and motor.Whatever colors you choose for yours,do a good job. Electrobike can be asharp-looking rig. When the kids get itout for a run around the block Dad willbe in line for his turn at the fun. Wannabet? •