PART I

For one-third the

price of a commercial

unit you can build

this 60-plus miles per

gallon motor scooter.

BY MARYLOU ANDPETER GERLACH

ESIGNED expressly for readers of ME-CHANIX ILLUSTRATED, the Super Scooter

can be constructed by anyone who has accessto the average number of metal-workingtools. The power Unit in the original is a1½-hp. Briggs & Stratton Series "N" air-cooled gasoline engine. This was consideredto be sufficient power for Jacksonville. Flor-ida, its home, because that area is so flat thathill-climbing ability isn't required. For hillycountry—or if you like to "get away" with azoom—we suggest you install the largerSeries "B" Briggs & Stratton power plant oran engine of comparable size. The interior ofthe MI Super Scooter is sufficiently large topermit easy mounting of the bulkiest ¾ hpengines on the market.

Although somewhat larger than the popularcommercial units, you'll find the MI SuperScooter as easy to ride as it is to build. Theleatherette upholstered seat and sprungwheels will make riding soft while the rearcompartment will easily accommodate a fairsized assortment of groceries, picnic lunch,tools or the like. And don't forget the 60 plusmiles to the gallon

3/16 X 2 STRAPIRON

SPRUNGWHEELFRAME

BICYCLE CHAINAND SPROCKETS

GEARBOX

BODY OUTLINESSHOWN BYPHANTOMLINES

3/16 X 2"STRAP IRON

ALL FRAME MEMBERS3/16" x 1-1/2" x 1-1/2"ANGLE IRON (OR NOTED)

D

The frame is built up entirely of angleiron and does not require any welding,which is unusual for a project of this type.The frame is covered with sheet alumi-num and contains simple, easy to develop,curves- Large working drawings of thisproject w i l l be available after Part II ap-pears in the July issue of MECHANIX IL-LUSTRATED, which goes on sale about June20. Building the frame wi l l be describedthis month; installation of the motor andall finishing touches, next month.

Begin construction by fabricating therear-wheel frame, which is detailed inFig. 1. It is made from eight pieces of3/16 x 1½ x 1½-in. angle iron and fastenedtogether with machine screws. The rear-wheel axle, which is a length of 1-in.standard steel pipe, is secured to i t , asshown in Photo No. 3, by means of twoeasily removable bolts. Two collars, madeof 1¼-in. pipe, slide on the axle betweenthe frame and the wheel to keep the latterproperly centered.

The main frame. Fig. 2, consists of twolongitudinal members, six cross pieces.

The rear set of main-frame cross members and therear-wheel frame are temporarily bolted together.

FRONT FRAME3/16" x 1-1/2" x 1-1/2"ANGLE IRON

1-1/4" BRONZEBUSHING

FRONT SPRING

GENERAL JUMBO14 x 4.50 x 6

119s c sMASONITE AND

DURAL FLOORINGBRAKEPEDAL

V-BELTDRIVE PULLEYS

IDLER

KICKSTARTERPEDAL

CLUTCH PEDAL

BRIGGS & STRATTONENGINE

HAND THROTTLEFORD CHOKE CONTROL

LARGE BICYCLEHANDLE BARS

Here, ready for final assembly, are a l l but theforwardmost angle-iron main-frame cross members.

Clearly shown here are the two semi-ellipticaltail pieces and the rear-wheel spring support.The engine has been temporarily set in placeto make sure that it will clear the framework.

Three layers, of different materials, make upthe flooring. On the bottom is a full-lengthpiece of Masonite. in the middle is a sheet ofboiler plate, and aluminum or dural is on top.

and 12 clips, all made of angle iron. Thetwo aftermost cross pieces are bolted to-gether to form a single unit, as detailedin Fig. 1. Mounted atop this unit are twoadditional angle-iron clips. These haveholes drilled in them to take the piece of¼-in. drill rod about which the rear-wheel frame pivots. Photo No. 2 showsthis cross member and the rear-wheelframe temporarily bolted together so youcan check clearances and alignment.

At this point, your work will be madeeasier if you construct a wooden jig tosupport the framework while you assem-ble it. The jig, which is made of two-by-fours and other scrap lumber, is shown inPhotos No. 4 and 5. When bolting thecomponent members of the frame to-gether, the t h r ee intermediate crosspieces are positioned to suit the engineselected, the two rear ones being placedunder the mounting lugs on the engine totake the hold-down bolts and the otherone being secured about halfway betweenthe forwardmost engine-bearing crosspiece and the front end of the frame.

Your next chore is to add the piece of3/16x2-in. strap iron, 148 in. long, to themain frame. Make a mark at the centerpoint of its length and bend it about thatpoint into a "U" shape, using one of thetires—which are 14.30 in. outside diam-eter—as a jig. Since the main frame iswider than the outside diameter of thetire, the part of the strap iron falling be-tween the frame and the "U" bend, eachside, should be gently curved to "fairinto" both the frame and the bend. Thiswill give a tail that is semielliptical inshape.

Next, install the rear-wheel spring sup-port, which is shown in Photo No. 5,bending it from a piece of 3/16x2-in. strap

Construct a jig of scrap lumber to support themain frame while you go on with the assembly.

Secure the rear-wheel axle, which is made ofsteel pipe, to the frame with bolts and nuts.

iron and securing it in place, at the pointindicated in Fig. 2, with ¼-in. No. 20 ma-chine screws.

The flooring is now added. It is madeup of three layers. On the bottom is a full-length piece of 1/8-in. Masonite. Next,extending from the rear cross piece to themiddle one, is a sheet of 1/8-in. boilerplate. And finally, on top is a layer of1/16-in. aluminum or dural (see Photo No.6).

The next step is to install the uprightpieces of the framework. Cut them tolength, as shown in Fig. 2: then drill and

MAIN-FRAMEREARCROSSMEMBER

10"MAXIMUM DRILL

1/4" HOLE

2-1/2" LONG

17-1/2"

1-1/8" LONG4 REQ'D.

1-1/2" LONG8 REQ'D.

MAIN-FRAMECROSS PIECE3/16 X 1-1/2 X 1-1/2"ANGLE IRON4 REQ'D.23"

13"

REAR-WHEEL FRAME3/16 X 1-1/2 X 1-1/2" ANGLE IRON

22-5/8" LONG

1"

DRILL 1/4"

DRILL 1/4"HOLE

10"MINIMUM

3/4"ALL SCREW HOLESDRILLED AND TAPPED1/4"- 20

10"

1-1/2" LONG, 4 REQ'D. 2 0 "S. C.S.

tap the holes and secure the pieces to thelower part of the main frame w i t h screwsand 18-in. lengths of angle iron.

Now is a good time to make sure thatthe engine that you have selected w i l l fitinto the scooter w i t h sufficient clearanceall around, especially if you have fol-lowed our advice and chosen a morepowerful one than was used in our ex-ample. Set it on the flooring at the pointwhere it w i l l ultimately be bolted. If i textends above or in front of the forwarduprights, you ' l l have to make them longeror move them farther forward.

After making this clearance test, re-move the engine and prepare and installthe upper piece of strap iron, bending i t ,as you did the lower one, around one ofthe tires and securing it to the uprightswi th machine screws. Note that its afterend doesn't extend as far to the rear asdoes that of the lower strap iron. Com-plete the frame by adding the two uppercross pieces.

You are now ready to proceed wi th thefront-strut assembly. The first step here

is to make the bearing. It is in threepieces and is cut from a 12-in. length ofbronze bushing, as shown in Fig. 3. Next,obtain a 12-in. length of 5/8-in. d r i l l rodto act as a shaft. The front struts, two foreach side, are cut to the lengths shown.After bolting them to the main frame atthe angle indicated, bend them inward sotheir upper ends are directly in line wi ththe center of the frame. This is importantbecause the balance and ease of steeringof the finished scooter depend on thesestruts being accurately centered. Theirupper ends are next screwed to the 8-in.length of bearing, taking care to set thebearing at exactly the angle given in Fig.3. Wi th the shaft inserted in place, thefront part of the frame w i l l look as inPhoto No. 8.

A glance at Photo No. 9 w i l l show thecomponent parts of the front end, whichis detailed in Fig. 4. Made of angle iron,it consists of six 8-in. cross pieces, two12½-in. spring retainers, and two 32-in.uprights. In addition, there are two 3/16-in.boiler-plate shaft mounts that are cut and

Mechanix Illustrated122

drilled as indicated. With the shaft inplace in the 8-in. bearing and the two2-in. bearings slid onto the ends of theshaft, the boiler-plate shaft mounts onthe assembled front end will just slideover the ends of the short bearings, towhich they are secured with machinescrews. To complete the front end, mounta large bicycle handlebar atop the top-most cross piece and securely bolt it inplace.

The front-wheel axle is a piece of 1-in.standard steel pipe, 7¾ in. long. Like therear one, the front wheel is centered bymeans of collar spacers. Passing througheach end of the axle is a length of ¼-in.drill rod. The front springs go over theserods.

The rest of the story, which will coverinstallation of the engine and drive, willbe described next month. Watch for theJuly MI! •

WE'RE now ready to go ahead on thesecond and final lap in the building

of Super Scooter. The first thing to dois to install the rear springs, Photo No. 11.These are of the compression type, 1-1/2 in.in diameter and, when extended, 9 in. long.They are held in place by two 11-in. lengthsof 1/4-in. drill rod that pass through holesdrilled in the rear-wheel frame and the3/16x2-in. spring support. Collars made from3/4-in. drill rod go over the ends of thesespring retainers and are secured with set-screws.

Next, the rear-wheel assembly is under-taken. The wheel is a General Jumbo,14x4:50x6, with ball-bearing rim. Alsoneeded is a 33-tooth sprocket, obtainableat your local bicycle supply store. To bringthe sprocket out the proper distance fromthe wheel hub, cut five spacers, 3-1/2 in.long, from 1/8-in. standard pipe. The wheel.spacers, and sprocket all appear in PhotoNo. 14. The brake drum and face plateare detailed in Fig. 5. Turn them downto their proper diameters on a lathe, using1-in. boiler plate for the drum and 1/4-in.boiler plate for the face plate. For the

Part 2

Compression-type springs, set betweensupport and the rear-wheel frame, ease

the springyour ride.

14

Five spacers, made from standard pipe, are usedto keep the sprocket away from hub of the wheel.

brake, use half of a 4-1/2-in. pipe clamp,adding the parts shown in Fig. 5 and rivet-ing commercial brake lining to the innersurface. The component parts of the brakeappear in Photo No. 12. Using Vix6-in.bolts, spacers, and nuts, the face plate anddrums are installed on the wheel as inPhoto No. 13. The brake itself is bolted tothe frame. A piece of Ford Model-T brakerod connects the brake and a pivoted bar atthe front of the scooter. This bar is in turncoupled with an activating foot pedal, Fig. 6.

The next item is the kick stand detailedin Fig. 7. It consists of a 1/2-in. steel rod,which is bent as shown and hung from theside frame with a spring, washer, and cotterpins, and a 1/4-in. plate with two groovesin it, which is suspended from the sideframe by means of two short pieces ofangle. The grooves provide "up" and"down" locking positions for the stand andthe spring serves to hold the stand inwhichever locking positions you desire.

Now is the time to decide what type ofdrive you are going to use. Two alterna-tives are given. The first. Photo No. 15, isthe one used in the original scooter. Thesecond, Fig. 8, is perhaps simpler and easierto install.

In the first installation, a 1:1 war-surplus gear box is used to change overfrom belt to chain drive. The sprocket shaftfrom this box must be placed in direct ver-tical line with the pivot point of the rear-wheel frame so the chain drive will movecorrectly with the frame. The sprocket isan eight-tooth affair. On the other shaftof the gear box goes a 4-in. pulley for a1/2-in.V-belt. A 3-1/2-in. pulley is put onthe engine shaft. The idler-type clutch isdetailed in Fig. 9. A 2-in. polished wheelis mounted in a pivoted yoke and the wholebolted to the flooring in such a manner that.

15

when the wheel is raised by depressing thefoot pedal, the V-belt is tightened about thetwo pulleys. Fig. 10 shows complete de-tails of the kick starter that was added tofacilitate starting the Briggs & StrattonSeries "N" engine. The gear can be se-cured from the Cushman Motor Works,Lincoln, Neb.

In the second installation, a larger en-

gine—the Briggs & Stratton Series "B"—is shown. Mounted directly on the driveshaft, is an AMSCO centrifugal clutch,manufactured by the American MotorScooter Co., 628 W. Lake Street, Chicago,111. Directly above the pivot point of therear-wheel frame is a 5/8-in. shaft that issupported by two pillow blocks. On thisshaft are a 3.6-in. pitch diameter "Bisec-tion pulley and an eight-tooth sprocket.A "B"-section V-belt couples the pulleyon the clutch and the one on the shaftand a chain connects the sprocket on theshaft and the one on the drive wheel.

Sizes of the various pieces making upHere's how the body looks with the Masonite andthe first three sheets of aluminum put in place.

BOILERPLATE

the body are given in Fig. 11. First cuttwo seat sides from 1-in. pine and one7xl7-in. back support from 1/2-in. plywood.The luggage flat, also of plywood, rests onthe rear spring support and the wall at itsforward end is bolted to the frame up-rights. Extending from the front edges ofthe forward frame uprights to the pointswhere the strap-iron tail frames start tocurve in, are two pieces of 1/8-in. Masonite,bolted to the framework. The back of thescooter is covered with a single sheet of1/16-in. aluminum. Two more pieces ofaluminum are placed over the Masoniteand seat sides. Photo No. 16 shows theprogress of the covering at this point. TheMasonite shown exposed in this picture isnext covered with aluminum. Now cut outthe luggage-compartment top and form itover a piece of plywood that is shaped tothe contour of the [Continued on page 168 ]

MI Super Scooter[Continued from page 150]

back top edge of the scooter frame. Twobutt hinges hold this cover in place. Next,make the seat from hardwood or plywood,pad it with 3 in. of Kapok, and cover it withleatherette. The back and arms of the seatare likewise padded and covered.

At the front end of the scooter, a piece of3/16 x 2-in. strap iron, 58 in. long is bent intoa "U" shape on a 7-in. radius and bolted tothe projecting ends of the 2-in. strap ironthat covers the main frame. A piece ofaluminum for the left front cover section isnow bolted to the forward strut and bentaround and bolted to the strap iron, PhotoNo. 17. Using the lower edge of the strap ironas a guide, scribe a line on the aluminum;then cut away the excess material. Install anidentical piece on the right side, overlappingthe left covering piece. Secure it in placewith a bolt passing through both coveringsand the strap iron. Draw a line down theexact center of the front covering and drillholes at 4-in. intervals; then put machinescrews through the two coverings, put onbolts, and tighten them home. An additionalsegment is added at the back end of each ofthese pieces to cover the rear pair of struts.A splash pan, if desired, is now installed. Itis triangular in shape to fit the openingframed by the two forward struts and theflooring and has three flanges that bolt to thestruts and the underside of the flooring.

Three wooden frames are next cut toshape, as shown in Fig. 11, and bolted to thefront-end assembly. An aluminum sheet isfastened to these frames and the uprightangle irons (see Photo No. 18).

The hand throttle is a 6-ft. Ford choke-control cable. The control end is fastened,with a hose clamp, to the righthand handlebar.The cable is then run down under the scooterand back up through a hole drilled at a pointdirectly below the engine's throttle control,to which the free end is connected. Install asix-volt bicycle spotlight and a small taillight.Power for the lights comes from a six-voltheavy-duty bicycle battery carried in theluggage compartment. A simple switch onthe battery turns on both lights.

Now the scooter is ready for painting. Theoriginal was finished in fire-engine red. Rub-ber matting, cut to fit the floor of the scooter,adds a final professional touch. A rubber heel,fastened to the floor where the kick starterhits prevents damage.

If you're going to use Super Scooter onpublic highways, you'll have to register it withyour state motor-vehicle commission and in-stall license plates. A length of flat bar boltedto the scooter acts as a license-plate bracket. •